Acoustic output device

Abstract

One or more embodiments of the present description relate to an acoustic output device, comprising: a housing in which an inner cavity is formed; a supporting structure, which enables the housing to be worn on the ear without blocking the external auditory meatus; a first loudspeaker, which is accommodated in the inner cavity, wherein the first loudspeaker comprises a first magnet and a first diaphragm, and the first magnet and the first diaphragm are spaced apart from each other in a vibration direction of the first diaphragm; and a second loudspeaker, which is accommodated in the inner cavity, wherein the second loudspeaker comprises a second magnet and a second diaphragm, and the second magnet and the second diaphragm are spaced apart from each other in a vibration direction of the second diaphragm.

Description

An acoustic output device Technical Field

[0001] This specification relates to the field of acoustic technology, and in particular to an acoustic output device. Background Technology

[0002] Open-back headphones are portable audio output devices that achieve directional sound conduction. Compared to traditional in-ear and over-ear headphones, open-back headphones are characterized by not blocking or covering the ear canal, allowing users to hear ambient sound while listening to music, thus improving safety and comfort. Speaker design is extremely important to ensure the sound quality of open-back headphones. To improve sound output, the speakers of open-back headphones require special design to meet the sound pressure level requirements of specific frequency bands.

[0003] Summary of the Invention

[0004] This specification provides an acoustic output device comprising: a housing forming an inner cavity; a support structure for wearing the housing on the ear without obstructing the external auditory canal; a first speaker housed within the inner cavity; the first speaker comprising a first magnet and a first diaphragm, the first magnet and the first diaphragm being spaced apart along the vibration direction of the first diaphragm; and a second speaker housed within the inner cavity; the second speaker comprising a second magnet and a second diaphragm, the second magnet and the second diaphragm being spaced apart along the vibration direction of the second diaphragm; wherein the first magnet and the second magnet are arranged spaced apart along the vibration direction of the first diaphragm; and the same magnetic poles of the first magnet and the second magnet are arranged opposite each other.

[0005] In some embodiments, at least a portion of the first speaker outputs a sound at a frequency lower than the frequency of the sound output by the second speaker.

[0006] In some embodiments, the axis of the first magnet is parallel to and spaced apart from the axis of the second magnet.

[0007] In some embodiments, a first sound outlet and a second sound outlet are provided on the inner side of the housing. The first sound outlet is acoustically coupled to the first diaphragm, and the second sound outlet is acoustically coupled to the second diaphragm. The inner side is the side of the housing facing the ear canal opening when worn.

[0008] In some embodiments, when worn, the centroid of the second sound outlet is projected onto the sagittal plane of the human body more closely than the centroid of the first sound outlet is projected onto the sagittal plane of the human body.

[0009] In some embodiments, when worn, the orthographic projection of the center of the second magnet onto the sagittal plane of the human body is closer to the ear canal opening than the orthographic projection of the center of the first magnet onto the sagittal plane of the human body.

[0010] In some embodiments, on the plane where the surface of the first magnet faces the first diaphragm, the orthographic projection of the second magnet at least partially overlaps with the orthographic projection of the first magnet.

[0011] In some embodiments, when worn, the housing extends at least partially into the concha of the ear, and at least a portion of the side of the housing abuts against the concha.

[0012] In some embodiments, the first diaphragm includes a main body region and a folded ring region surrounding the main body region. The main body region includes an arched dome. The projection of the center of the second magnet along the axial direction of the second magnet onto the first diaphragm is located between the center of the dome and the inner edge of the folded ring, and the inner edge of the folded ring is connected to the dome.

[0013] In some embodiments, the cavity includes a first cavity and a second cavity separated from each other, the first speaker being housed in the first cavity and the second speaker being housed in the second cavity.

[0014] In some embodiments, the first distance between the magnetic circuit containing the first magnet and the magnetic circuit containing the second magnet along the vibration direction of the first diaphragm is 2.85mm-3.42mm.

[0015] In some embodiments, the first distance between the magnetic circuit containing the first magnet and the magnetic circuit containing the second magnet along the vibration direction of the first diaphragm is 3mm-3.2mm.

[0016] In some embodiments, on the plane where the surface of the first magnet faces the first diaphragm, the distance between the orthographic projection of the centroid of the first diaphragm and the orthographic projection of the centroid of the second diaphragm is 0mm-8mm.

[0017] In some embodiments, the second speaker further includes a third magnet disposed around the second magnet.

[0018] In some embodiments, the second speaker further includes a fourth magnet, which is arranged with the second magnet along the vibration direction of the second diaphragm, and the same magnetic poles of the fourth magnet and the second magnet are arranged opposite to each other.

[0019] In some embodiments, the ratio of the area of ​​the cross-section of the second magnet along the direction perpendicular to the axis of the second magnet to the area of ​​the cross-section of the third magnet along the direction perpendicular to the axis of the third magnet is 0.1-4.

[0020] In some embodiments, the ratio of the area of ​​the cross-section of the second magnet along the direction perpendicular to the axis of the second magnet to the area of ​​the cross-section of the third magnet along the direction perpendicular to the axis of the third magnet is 0.4-0.6.

[0021] In some embodiments, the first loudspeaker includes a first coil connected to the first diaphragm and at least partially located in the magnetic field formed by the first magnet. When the first coil is energized, it drives the first diaphragm to vibrate to generate sound. The magnetic induction intensity value at any position on the first coil is greater than 0.45T.

[0022] In some embodiments, the second loudspeaker includes a second coil connected to the second diaphragm and at least partially located in the magnetic field formed by the second magnet. When the second coil is energized, it drives the second diaphragm to vibrate to generate sound. The magnetic induction intensity value at any position on the second coil is greater than 0.3T.

[0023] This embodiment also provides an acoustic output device, comprising: a housing forming an inner cavity; a support structure for wearing the housing on the ear without blocking the external auditory canal; a first speaker housed within the inner cavity; the first speaker comprising a first magnet and a first diaphragm, the first magnet and the first diaphragm being spaced apart along the vibration direction of the first diaphragm; and a second speaker housed within the inner cavity; the second speaker comprising a second magnet and a second diaphragm, the second magnet and the second diaphragm being spaced apart along the vibration direction of the second diaphragm; wherein the axis of the second magnet is inclined relative to the axis of the first magnet.

[0024] In some embodiments, on the plane where the surface of the first magnet faces the first diaphragm, there is a gap between the orthographic projection of the second diaphragm and the orthographic projection of the first diaphragm.

[0025] In some embodiments, at least a portion of the first speaker outputs a sound at a frequency lower than the frequency of the sound output by the second speaker.

[0026] In some embodiments, the lower side of the housing is provided with a first sound outlet and a second sound outlet, the first sound outlet being acoustically coupled to the first diaphragm, and the second sound outlet being acoustically coupled to the second diaphragm; the lower side is the side of the housing facing away from the user's head when worn.

[0027] In some embodiments, a first sound outlet is provided on the inner side of the housing, and a second sound outlet is provided on the lower side of the housing. The first sound outlet is acoustically coupled to the first diaphragm, and the second sound outlet is acoustically coupled to the second diaphragm. The inner side is the side of the housing facing the antihelix when worn, and the lower side is the side of the housing away from the top of the user's head when worn.

[0028] In some embodiments, the axis of the first magnet is perpendicular to the axis of the second magnet, and the first magnet and the second magnet are spaced apart along the vibration direction of the second diaphragm.

[0029] In some embodiments, the angle between the axis of the first magnet and the axis of the second magnet is 10°-45°.

[0030] In some embodiments, the third distance between the magnetic circuit containing the first magnet and the magnetic circuit containing the second magnet is 1.5mm-2.5mm.

[0031] In some embodiments, when worn, the support structure positions the housing at the antihelix of the ear, and a portion of the side of the housing abuts against the antihelix.

[0032] In some embodiments, the cavity includes a first cavity and a second cavity separated from each other, the first speaker being housed in the first cavity and the second speaker being housed in the second cavity.

[0033] In some embodiments, the second speaker further includes a third magnet disposed around the second magnet.

[0034] In some embodiments, the second speaker further includes a fourth magnet, the second magnet and the fourth magnet being arranged along the vibration direction of the second diaphragm; and the same magnetic poles of the second magnet and the fourth magnet being arranged opposite to each other.

[0035] In some embodiments, the ratio of the area of ​​the cross-section of the second magnet along the direction perpendicular to the axis of the second magnet to the area of ​​the cross-section of the third magnet along the direction perpendicular to the axis of the third magnet is 0.1-4.

[0036] In some embodiments, the ratio of the area of ​​the cross-section of the second magnet along the direction perpendicular to the axis of the second magnet to the area of ​​the cross-section of the third magnet along the direction perpendicular to the axis of the third magnet is 0.4-0.6.

[0037] In some embodiments, the first loudspeaker includes a first coil connected to the first diaphragm and at least partially located in the magnetic field formed by the first magnet. When the first coil is energized, it drives the first diaphragm to vibrate to generate sound. The magnetic induction intensity at any position on the first coil is 0.44T-0.67T.

[0038] In some embodiments, the second loudspeaker includes a second coil connected to the second diaphragm and at least partially located in the magnetic field formed by the second magnet. When the second coil is energized, it drives the second diaphragm to vibrate to generate sound. The magnetic induction intensity at any position on the second coil is 0.3T-0.6T. Attached Figure Description

[0039] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0040] Figure 1 is a schematic diagram of an exemplary ear according to some embodiments of this application;

[0041] Figure 2 is an exemplary wearing diagram of an open-back headphone according to some embodiments of this specification;

[0042] Figure 3A is an exemplary frame structure diagram of an acoustic output device according to some embodiments of this specification;

[0043] Figure 3B is an exemplary structural schematic diagram of an acoustic output device according to some embodiments of this specification;

[0044] Figure 3C is an exemplary structural schematic diagram of an acoustic output device according to some other embodiments of this specification;

[0045] Figure 4 is an exemplary internal structure diagram of a first loudspeaker according to some embodiments of this specification;

[0046] Figure 5A is a diagram showing the positional relationship of the first and second loudspeakers and the magnetic field distribution according to some embodiments of this specification;

[0047] Figure 5B is a magnetic field distribution diagram of a first loudspeaker according to some embodiments of this specification;

[0048] Figure 6A is an exemplary wearing diagram of an acoustic output device according to some embodiments of this specification;

[0049] Figure 6B is an exemplary distribution diagram of a cavity structure arranged around one of the sound sources of a dual sound source according to some embodiments of this specification;

[0050] Figure 7A is a schematic diagram showing that the first loudspeaker and the second loudspeaker have different relative positions in the horizontal direction according to some embodiments of this specification;

[0051] Figure 7B is a schematic diagram of the magnetic field distribution of the first and second loudspeakers according to some embodiments of this specification;

[0052] Figure 7C is a graph showing the variation trend of magnetic induction intensity at the first coil end point of the first loudspeaker when the first loudspeaker and the second loudspeaker have different relative positions in the horizontal direction according to some embodiments of this specification.

[0053] Figure 7D is a graph showing the variation trend of the average magnetic induction intensity at the first coil according to some embodiments of this specification;

[0054] Figure 8 is an exemplary structural diagram of a second loudspeaker according to some embodiments of this specification;

[0055] Figure 9 is another exemplary structural diagram of a second loudspeaker according to some embodiments of this specification;

[0056] Figure 10 is a sound pressure level graph of a second loudspeaker with a dual-magnet and a triple-magnet configuration according to some embodiments of this specification;

[0057] Figure 11A is a schematic diagram of the structure of the second magnet and the third magnet according to some embodiments of this specification;

[0058] Figure 11B is a schematic diagram of the structure of the second and third magnets according to some other embodiments of this specification;

[0059] Figure 11C is a graph showing the effect of the area ratio of the second magnet to the third magnet on the magnetic induction intensity at the first coil according to some embodiments of this specification.

[0060] Figure 12 is another structural diagram of an acoustic output device according to some embodiments of this specification;

[0061] Figure 13A is a schematic diagram of another wearing method of the acoustic output device according to some embodiments of this specification;

[0062] Figure 13B is an exemplary structural diagram showing a baffle between two sound sources according to some embodiments of this specification;

[0063] Figure 14 is a schematic diagram of the magnetic field distribution of the first and second speakers according to some embodiments of the present specification.

[0064] Figure 15 is a schematic diagram of the magnetic field distribution of the first and second speakers under a magnet arrangement method three according to some embodiments of this specification. Detailed Implementation

[0065] To more clearly illustrate the technical solutions of the embodiments in this specification, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this specification. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0066] It should be understood that the terms “system,” “device,” “unit,” and / or “module” used herein are one way to distinguish different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0067] As indicated in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0068] In the description of this specification, it should be understood that the terms "first," "second," "third," "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include at least one of that feature. In the description of this specification, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0069] In this specification, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, the term "connection" can refer to a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this specification according to the specific circumstances.

[0070] Flowcharts are used in this specification to illustrate the operations performed by the system according to embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0071] Figure 1 is a schematic diagram of an exemplary ear according to some embodiments of this application. Referring to Figure 1, the ear 100 may include an external auditory canal 101, a concha 102, a cymba concha 103, a triangular fossa 104, an antihelix 105, a scaphoid fossa 106, a helix 107, an earlobe 108, and a crus of the helix 109. In some embodiments, the wearing and stabilization of an acoustic output device can be achieved by means of one or more parts of the ear 100. In some embodiments, the external auditory canal 101, the concha 102, the cymba concha 103, the triangular fossa 104, etc., have a certain depth and volume in three-dimensional space, which can be used to meet the wearing requirements of the acoustic output device. For example, an acoustic output device (e.g., an in-ear headphone) can be worn in the external auditory canal 101. In some embodiments, the wearing of the acoustic output device can be achieved by means of other parts of the ear 100 besides the external auditory canal 101. For example, the acoustic output device can be worn using parts such as the cymba conchae 103, triangular fossa 104, antihelix 105, scaphoid fossa 106, and helix 107, or combinations thereof. In some embodiments, to improve the comfort and reliability of the acoustic output device during wear, it can also be further utilized using parts such as the user's earlobe 108. By utilizing parts of the ear 100 other than the external auditory canal 101 to achieve the wearing of the acoustic output device and the propagation of sound, the user's external auditory canal 101 can be "liberated," reducing the impact of the acoustic output device on the user's ear health. When the user wears the acoustic output device on the road, the acoustic output device will not block the user's external auditory canal 101, and the user can receive both the sound from the acoustic output device and the sound from the environment (e.g., horns, car bells, surrounding voices, traffic signals, etc.), thereby reducing the probability of traffic accidents. For example, when the user wears the acoustic output device, the entire or part of the acoustic output device can be located on the front side of the helix foot 109 (e.g., the area J enclosed by the dotted line in Figure 1). For example, when a user wears the acoustic output device, the entire or part of the acoustic output device may contact the upper part of the external auditory canal 101 (e.g., the location of one or more parts such as the helix crus 109, cymba conchae 103, triangular fossa 104, antihelix 105, scaphoid fossa 106, and helix 107). As another example, when a user wears the acoustic output device, the entire or part of the acoustic output device may be located within one or more parts of the ear (e.g., the conchae cavity 102, cymba conchae 103, triangular fossa 104, etc.) (e.g., areas M1 and M2 enclosed by dashed lines in Figure 1).

[0072] Individual differences may exist among users, resulting in variations in ear shape, size, and other dimensional differences. For ease of description and understanding, unless otherwise specified, this specification will primarily use an ear model with a "standard" shape and size as a reference to further describe how the acoustic output device in different embodiments is worn on this ear model. For example, a simulator containing the head and its (left and right) ears, such as GRAS KEMAR, HEAD Acoustics, B&K 4128 series, or B&K 5128 series, manufactured based on ANSI:S3.36, S3.25, and IEC:60318-7 standards, can be used as a reference for wearing the acoustic output device, thus representing the scenario of most users normally wearing the acoustic output device. Taking GRAS KEMAR as an example, the ear simulator can be any one of GRAS 45AC, GRAS 45BC, GRAS 45CC, or GRAS 43AG. Using HEAD Acoustics as an example, the ear simulator can be any one of HMS II.3, HMS II.3LN, or HMS II.3LN HEC. It should be noted that the data range measured in the embodiments of this specification is based on GRAS 45BC KEMAR measurements. However, it should be understood that differences may exist between different head and ear models, and the relevant data range may fluctuate by ±10% when using other models. As an example only, the ear used for reference may have the following characteristics: the projection of the auricle onto the sagittal plane in the vertical axis direction can be in the range of 49.5mm-74.3mm, and the projection of the auricle onto the sagittal plane in the sagittal axis direction can be in the range of 36.6mm-55mm. The projection of the auricle onto the sagittal plane refers to the projection of the edge of the auricle onto the sagittal plane. The edge of the auricle is composed at least of the outer contour of the helix, the contour of the earlobe, the contour of the tragus, the intertragic notch, the antitragic cusp, and the helix-tragic notch. Therefore, in this application, descriptions such as "user wearing," "in wearing state," and "under wearing state" can refer to the acoustic output device described in this application being worn on the ear of the aforementioned simulator. Of course, considering the individual differences among different users, the structure, shape, size, thickness, etc. of one or more parts of the ear 100 can be differentiated according to different ear shapes and sizes. These differentiated designs can be manifested in that the characteristic parameters of one or more parts of the acoustic output device (e.g., the sound-emitting part, ear hook, etc. mentioned below) can have different ranges of values ​​to adapt to different ears.

[0073] It should be noted that in medicine, anatomy, and other fields, the human body can be defined by three basic planes: the sagittal plane, the coronal plane, and the horizontal plane; and three basic axes: the sagittal axis, the coronal axis, and the vertical axis. The sagittal plane is a section perpendicular to the ground along the anteroposterior direction of the body, dividing the body into left and right parts. The coronal plane is a section perpendicular to the ground along the left and right direction of the body, dividing the body into anterior and posterior parts. The horizontal plane is a section parallel to the ground along the vertical direction of the body, dividing the body into superior and inferior parts. Correspondingly, the sagittal axis is the axis along the anteroposterior direction of the body and perpendicular to the coronal plane; the coronal axis is the axis along the left and right direction of the body and perpendicular to the sagittal plane; and the vertical axis is the axis along the vertical direction of the body and perpendicular to the horizontal plane.

[0074] The description of the ear 100 above is for illustrative purposes only and is not intended to limit the scope of this application. Those skilled in the art can make various changes and modifications based on the description in this application. For example, part of the acoustic output device may cover part or all of the external auditory canal 101. These changes and modifications are still within the protection scope of this application.

[0075] Figure 2 is an exemplary wearing diagram of an acoustic output device according to some embodiments of this specification. In some embodiments, the acoustic output device 10 may include, but is not limited to, air conduction headphones and bone conduction headphones. In some embodiments, the acoustic output device 10 may be combined with products such as glasses, headphones, head-mounted displays, and AR / VR helmets. As shown in Figure 2, the acoustic output device 10 may include a housing 11 and a support structure 12. The housing 11 forms an inner cavity, and one or more speakers are located in the inner cavity formed by the housing 11. The support structure 12 holds the housing 11 in place on the ear without blocking the external auditory canal. In some embodiments, the support structure 12 may be an ear hook 12. In some embodiments, the acoustic output device 10 can be worn on the user's body (e.g., the head, neck, or upper torso) via the ear hook 12.

[0076] In some embodiments, when the acoustic output device 10 is worn, the first portion of the ear hook 12 is hung between the user's auricle and head, and the second portion extends towards the side of the auricle away from the head and connects to the sound-emitting part 11, for fixing the housing 11 near the ear canal without blocking the ear canal. In some embodiments, the ear hook 12 can be an arc structure adapted to the user's auricle, so that the ear hook 12 can be suspended on the user's upper auricle. In some embodiments, the ear hook 12 can also be a clamping structure adapted to the user's auricle, so that the ear hook 12 can be clamped on the user's auricle. In some embodiments, the ear hook 12 can include, but is not limited to, a hook structure, an elastic band, etc., so that the acoustic output device 10 can be better fixed to the user and prevent the user from falling off during use.

[0077] In some embodiments, the housing 11 can be worn on a user's body, and the housing 11 contains a speaker (e.g., a first speaker and / or a second speaker) to generate sound input to the user's ear 100. In some embodiments, the acoustic output device 10 can be combined with products such as glasses, headphones, head-mounted displays, AR / VR helmets, etc., in which case the housing 11 can be worn near the user's ear 100 by suspension or clipping. In some embodiments, the housing 11 can be annular, elliptical, polygonal (regular or irregular), U-shaped, V-shaped, or semi-circular, so that the housing 11 can be directly attached to the user's ear 100.

[0078] Referring to Figures 1 and 2, in some embodiments, when a user wears the acoustic output device 10, at least a portion of the housing 11 may be located in region J on the front side of the tragus of the user's ear 100 as shown in Figure 1, or in regions M1 and M2 within the auricle. The following will provide illustrative examples of different wearing positions of the housing 11 (positions 11A, 11B, and 11C shown in Figure 2). It should be noted that, in the embodiments of this specification, the anterolateral surface of the auricle refers to the side of the auricle facing away from the head along the coronal axis; correspondingly, the posteromedial surface of the auricle refers to the side of the auricle facing the head along the coronal axis. In some embodiments, the housing 11 being located at position 11A means that the housing 11 is located on the side of the user's ear 100 facing the facial region along the sagittal axis, i.e., the housing 11 is located in region J on the front side of the ear 100.

[0079] In some embodiments, the housing 11 contains one or more speakers. Based on frequency, the speaker types may include low-frequency (e.g., 30Hz-150Hz) speakers, mid-low-frequency (e.g., 150Hz-500Hz) speakers, mid-high-frequency (e.g., 500Hz-5kHz) speakers, high-frequency (e.g., 5kHz-16kHz) speakers, or full-range (e.g., 30Hz-16kHz) speakers, or any combination thereof. The terms "low frequency," "high frequency," etc., refer only to approximate frequency ranges; different division methods may be used in different application scenarios. For example, a crossover point can be defined, with low frequency representing the frequency range below the crossover point and high frequency representing the frequency range above the crossover point. This crossover point can be any value within the audible range of the human ear, such as 500Hz, 800Hz, 1000Hz, 2000Hz, 4000Hz, 8000Hz, etc.

[0080] In some embodiments, the loudspeaker may include a diaphragm. When the diaphragm vibrates, sound can be emitted from the front and rear sides of the diaphragm, respectively. The cavity formed by the housing of the acoustic output device 10 is at least divided by the diaphragm into a front cavity located on the front side of the diaphragm and a rear cavity located on the rear side of the diaphragm. The front cavity is acoustically coupled to a sound outlet on the side of the housing. The vibration of the diaphragm causes the air in the front cavity to vibrate, generating air-conducted sound. The air-conducted sound generated in the front cavity propagates to the outside through the sound outlet.

[0081] In some embodiments, the housing 11 may have a major axis direction Y and a minor axis direction Z that are perpendicular to the thickness direction X and orthogonal to each other. The major axis direction Y can be defined as the direction with the maximum extension dimension in the shape of the two-dimensional projection plane of the housing 11 (e.g., the projection of the housing 11 onto the plane containing its outer surface, or its projection onto the sagittal plane). (e.g., when the projected shape is rectangular or approximately rectangular, the major axis direction is the length direction of the rectangle or approximately rectangular shape). The minor axis direction Z can be defined as the direction perpendicular to the major axis direction Y in the shape of the housing 11 projected onto the sagittal plane (e.g., when the projected shape is rectangular or approximately rectangular, the minor axis direction is the width direction of the rectangle or approximately rectangular shape). The thickness direction X can be defined as a direction perpendicular to the two-dimensional projection plane, for example, consistent with the direction of the coronal axis, both pointing towards the left and right sides of the body. In some embodiments, when the housing 11 is tilted while in the wearing state, the major axis direction Y and the minor axis direction Z are still parallel or approximately parallel to the sagittal plane. The major axis direction Y may have a certain angle with the direction of the sagittal axis, that is, the major axis direction Y is also tilted accordingly. The minor axis direction Z may have a certain angle with the direction of the vertical axis, that is, the minor axis direction Z is also tilted.

[0082] In some embodiments, the entire or partial structure of the housing 11 can extend into the concha cavity, meaning that the projection of the housing 11 in the sagittal plane overlaps with the projection of the concha cavity in the sagittal plane. For details regarding the housing 11 being worn at position 11B, please refer to other parts of this specification, such as Figure 6A and its related description. In some embodiments, the housing 11 can also be in a horizontal or approximately horizontal state when worn, as shown in Figure 2 where the housing 11 is worn at position 11C. The major axis direction Y can be aligned with or approximately aligned with the sagittal axis, both pointing in the front-back direction of the body, and the minor axis direction Z can be aligned with or approximately aligned with the vertical axis, both pointing in the up-down direction of the body. For details regarding the housing 11 being worn at position 11C, please refer to other parts of this specification, such as Figure 13A and its related description. When the acoustic output device 10 is worn in different ways (i.e., the position of the housing 11 relative to the ear is different), the speaker of the acoustic output device 10 is configured differently to improve the sound output effect, as shown in Figures 3A-15 and their related descriptions. It should be noted that, in the wearing state, the shell 11 being in an approximately horizontal state can mean that the angle between the long axis of the shell 11 and the sagittal axis, as shown in Figure 2, is within a specific range (e.g., no greater than 20°). Furthermore, the wearing position of the shell 11 is not limited to 11A, 11B, and 11C shown in Figure 2, but can satisfy regions J, M1, or M2 shown in Figure 1. For example, the entire or part of the shell 11 can be located in region J enclosed by the dotted line in Figure 1. As another example, the entire or part of the shell 11 can contact one or more of the following locations of the external auditory canal 101: the crus 109, cymba conchae 103, triangular fossa 104, antihelix 105, scaphoid fossa 106, and helix 107. For example, the entire or part of the structure of the shell 11 may be located within the cavity formed by one or more parts of the ear 100 (e.g., the concha 102, the cymba concha 103, the triangular fossa 104, etc.) (e.g., the region M1 enclosed by the dashed line in FIG1, which at least includes the cymba concha 103 and the triangular fossa 104, and the region M2 which at least includes the concha 102).

[0083] In some embodiments, to improve the stability of the acoustic output device 10 in the wearing state, the acoustic output device 10 may employ any one or a combination of the following methods. For example, at least a portion of the ear hook 12 is configured as a conformal structure that conforms to at least one of the back of the ear and the head to increase the contact area between the ear hook 12 and the ear and / or the head, thereby increasing the resistance to the acoustic output device 10 falling off the ear. For example, at least a portion of the ear hook 12 is configured as an elastic structure, so that it has a certain deformation in the wearing state to increase the positive pressure of the ear hook 12 on the ear and / or the head, thereby increasing the resistance to the acoustic output device 10 falling off the ear. For example, at least a portion of the ear hook 12 is configured to rest against the head in the wearing state, so as to form a reaction force that holds the ear, so that the housing 11 is held against the front of the ear, thereby increasing the resistance to the acoustic output device 10 falling off the ear. For example, the housing 11 and ear hook 12 are configured to clamp the physiological parts of the ear, such as the antihelix and concha, from both the front and back sides when worn, thereby increasing the resistance to the acoustic output device 10 falling off the ear. As another example, the housing 11 or the auxiliary structure connected to it is configured to at least partially extend into the physiological parts of the concha, cymba conchae, triangular fossa, and scaphoid fossa, thereby increasing the resistance to the acoustic output device 10 falling off the ear.

[0084] Figure 3A is an exemplary frame structure diagram of an acoustic output device according to some embodiments of this specification, Figure 3B is an exemplary structural schematic diagram of an acoustic output device according to some embodiments of this specification, and Figure 3C is an exemplary structural schematic diagram of an acoustic output device according to other embodiments of this specification. Referring to Figures 3A-3C, the acoustic output device 300 includes a housing 310, a support structure 320, a first speaker 330, and a second speaker 340. In some embodiments, the housing 310 may be a frame with a hollow structure. The housing 310 forms an inner cavity for accommodating other components of the acoustic output device 300 (e.g., the first speaker 330 and the second speaker 340). In some embodiments, the housing 310 may also protect the components housed in the inner cavity. As an example, Figures 3B and 3C illustrate two different positional relationships of the first speaker 330 and the second speaker 340, respectively.

[0085] The support structure 320 can be used to support the acoustic output device 300. When the acoustic output device 300 is in the wearing state, the support structure 320 is located on the ear and supports the housing 310, so that the housing 310 is worn on the ear but does not block the external auditory canal. Not blocking the external auditory canal can mean that the external auditory canal is at least partially able to communicate with the external environment. In some embodiments, the support structure 320 may include an ear hook. For more details about the ear hook, please refer to the relevant description of the ear hook 12 in Figure 2 of this specification, which will not be repeated here.

[0086] The first loudspeaker 330 is housed within the cavity formed by the housing 310. The first loudspeaker 330 converts electrical signals into sound signals and outputs them. In some embodiments, the first loudspeaker 330 may include a first magnet 331 and a first diaphragm 332. The first magnet 331 and the first diaphragm 332 are spaced apart along the vibration direction of the first diaphragm 332. The first diaphragm 332 can divide the cavity formed by the housing 310 into a first front cavity and a first rear cavity. The first front cavity of the first loudspeaker 330 may be a cavity formed on the side of the first diaphragm 332 facing away from the first magnet 331 (also referred to as the front side of the first diaphragm 332), and the first rear cavity of the first loudspeaker 330 may be a cavity formed on the side of the first diaphragm 332 facing the first magnet 331 (also referred to as the rear side of the first diaphragm 332) or on the side of the first magnet 331 facing away from the first diaphragm 332. The first magnet 331 is used to generate a magnetic field. The first diaphragm 332 may be connected to a coil; when the coil is energized, it vibrates under the influence of the magnetic field, causing the first diaphragm 332 to vibrate. When the first diaphragm 332 vibrates, the front and rear sides of the first diaphragm 332 will generate sound respectively. The sound generated by the front side of the first diaphragm 332 will radiate outward through the first front cavity, and the sound generated by the rear side of the first diaphragm 332 will radiate outward through the first rear cavity.

[0087] Figure 4 is an exemplary internal structural diagram of a first loudspeaker according to some embodiments of this specification. A bracket 334 is arranged around the first diaphragm 322, the first coil 333, and the magnetic circuit assembly 336, providing a mounting platform. The first loudspeaker 330 can be connected to the housing 310 of the acoustic output device 300 via the bracket 334. The first coil 333 extends into the magnetic circuit assembly 336 and is connected to the first diaphragm 322. The magnetic circuit assembly 336 exerts a force on the energized first coil 333, thereby driving the first diaphragm 322 to produce mechanical vibration, which in turn generates sound through the propagation of a medium such as air, and the sound is output through the sound outlet. In some embodiments, the magnetic circuit assembly 336 includes a magnetic guide plate 3361, a first magnet 331, and a receiving member 3363. The magnetic guide plate 3361 and the first magnet 331 are interconnected. The side of the first magnet 331 away from the magnetic guide plate 3361 is mounted on the bottom wall of the receiving member 3363, and there is a gap between the periphery of the first magnet 331 and the inner periphery of the receiving member 3363. In some embodiments, the outer periphery of the receiving member 3363 is connected and fixed to the bracket 334. In some embodiments, the receiving member 3363 includes a bottom 3363a and a periphery sidewall 3363b, which form a receiving space in which the magnetic guide plate 3361 and the first magnet 331 are received. The magnetic plate 3361 is interconnected with the first magnet 331. The side of the first magnet 331 away from the magnetic plate 3361 is mounted on the bottom 3363a of the receiving member, and there is a gap between the periphery of the first magnet 331 and the side wall 3363b of the periphery of the receiving member 3363. In some embodiments, the first coil 333 can extend into the gap between the first magnet 331 and the side wall 3363b.

[0088] In some embodiments, the first speaker 330 can be a low-frequency speaker or a mid-low-frequency speaker, and the first sound output by the first speaker 330 is a low-frequency sound or a mid-low-frequency sound. In some embodiments, the first speaker 330 outputs sound, such as a low-frequency sound or a mid-low-frequency sound, through a first front cavity and a first sound outlet formed on the housing 310. In some embodiments, in order to ensure that the acoustic output device 300 can output sound across the entire frequency range, that is, the acoustic output device 300 can output high-frequency sound while also outputting low-frequency or mid-low-frequency sound, a second speaker 340 can be provided in the acoustic output device 300.

[0089] The second speaker 340 is housed within the cavity formed by the housing 310. The second speaker 340 can convert electrical signals into sound signals and output them. In some embodiments, the second speaker 340 can function as a high-frequency speaker, and the second sound output by the second speaker 340 is a high-frequency sound. In some embodiments, the frequency range of the first sound output by the first speaker 330 and the frequency range of the second sound output by the second speaker 340 may not overlap. For example, the minimum frequency in the frequency range of the second sound is higher than the maximum frequency in the frequency range of the first sound. In some embodiments, the frequency range of the first sound output by the first speaker 330 and the frequency range of the second sound output by the second speaker 340 may overlap. For example, the minimum frequency in the frequency range of the second sound may not exceed the maximum frequency in the frequency range of the first sound, and the maximum frequency in the frequency range of the second sound is higher than the maximum frequency in the frequency range of the first sound. In some embodiments, the following frequency band definition method can be adopted: considering that the first speaker 330 may also emit a small high-frequency sound, the sound amplitude point within a frequency band can be used as a reference, and the frequency point that is lower than the highest amplitude point by more than a certain threshold can be used as the boundary point of the frequency band. A specific threshold frequency can be a frequency corresponding to a certain percentage of the highest amplitude point. For example, frequencies corresponding to amplitude points at 5%, 10%, or 15% of the highest amplitude point. It should be noted that the terms low frequency, mid-low frequency, and high frequency used here only indicate relative frequency magnitude, and different classification methods can be used in different application scenarios. For example, a crossover point can be defined, with low frequency representing the frequency range below the crossover point and high frequency representing the frequency range above the crossover point. This crossover point can be any value within the audible range of the human ear, such as 500Hz, 800Hz, 1000Hz, 2000Hz, 4000Hz, 8000Hz, etc. Furthermore, it should be clarified that high frequency and low frequency in this specification refer to relatively higher and relatively lower frequencies in comparison. For example, if the first speaker is a low-frequency speaker and the second speaker is a high-frequency speaker, it can mean that, compared to the first speaker, the first speaker outputs a lower frequency sound, and the second speaker outputs a higher frequency sound.

[0090] By setting the first speaker 330 and the second speaker 340 to output sounds in different frequency ranges respectively, such as the first speaker 330 outputting low-frequency or mid-low-frequency sounds and the second speaker 340 outputting high-frequency sounds, the sound effect of the acoustic output device can be improved in a wider frequency range.

[0091] In some embodiments, the second loudspeaker 340 may include a second magnet 341 and a second diaphragm 342. The second magnet 341 and the second diaphragm 342 are spaced apart along the vibration direction of the second diaphragm 342. The second diaphragm 342 can divide the cavity formed by the housing of the second loudspeaker 340 into a second front cavity and a second rear cavity. The second front cavity of the second loudspeaker 340 may be a cavity formed on the side of the second diaphragm 342 facing away from the second magnet 341 (also referred to as the front side of the second diaphragm 342), and the second rear cavity of the second loudspeaker 340 may be a cavity formed on the side of the second diaphragm 342 facing the second magnet 341 (also referred to as the rear side of the second diaphragm 342) or on the side of the second magnet 341 facing away from the second diaphragm 342. The second magnet 341 can be used to generate a magnetic field. When the second diaphragm 342 vibrates, the front and rear sides of the second diaphragm 342 generate sound respectively. The sound generated on the front side of the second diaphragm 342 is radiated outward through the second front cavity and a second sound outlet that is acoustically connected to the second front cavity. In some embodiments, the first sound outlet and the second sound outlet are two different sound outlets. The first sound outlet is used to radiate the sound generated by the first speaker 330 to the outside, and the second sound outlet is used to radiate the sound generated by the second speaker 340 to the outside. In other words, the first speaker 330 and the second speaker 340 do not share a sound outlet, and the first front cavity of the first speaker 330 and the second front cavity of the second speaker 340 are not connected.

[0092] In some embodiments, the second loudspeaker 340 may include a second coil and a magnetic circuit assembly. When current flows through the second coil, the magnetic circuit assembly exerts a force on the energized second coil. The second coil vibrates under the influence of the magnetic field, driving the second diaphragm 342 to produce mechanical vibration, which then generates sound through propagation via a medium such as air. In some embodiments, the magnetic circuit assembly of the second loudspeaker 340 may include one or more magnets. For example, the magnetic circuit assembly of the second loudspeaker 340 may include a second magnet 341. As another example, to increase the magnetic field strength at the second coil, a third magnet may be disposed around the second magnet 341, forming a magnetic circuit in which the second coil is located. As yet another example, the magnetic circuit assembly of the second loudspeaker 340 may further include a fourth magnet. Specific schemes for different numbers of magnets in the magnetic circuit assembly can be found elsewhere in this specification, such as Figures 8 and 9 and their related content. It should also be noted that, as the second loudspeaker 340 is a high-frequency loudspeaker, to ensure a small size, the magnetic circuit assembly of the second loudspeaker 340 may not include a housing. Specifically, in some embodiments, the second speaker 340 may include a spacer (not shown) for carrying the magnetic circuit assembly of the second speaker 340 and cooperating with the housing 310 to fix the second speaker 340. In some embodiments, the spacer may be a metal piece with magnetic properties and connected to the housing 310 by means of embedding or snap-fitting.

[0093] Figure 5A is a structural diagram showing the positional relationship of the first loudspeaker and the second loudspeaker according to some embodiments of this specification. Referring to Figure 5A, the first loudspeaker 330 and the second loudspeaker 340 can be stacked and spaced apart along the vibration direction of the first diaphragm 332 (the first vibration direction shown in Figure 5A) or the second vibration direction of the second diaphragm 342. In this case, the first magnet 331 and the second magnet 341 are arranged spaced apart along the vibration direction of the first diaphragm 332. In some embodiments, the first vibration direction of the first diaphragm 332 and the second vibration direction of the second diaphragm 342 are parallel. The vibration direction of the first diaphragm 332 is parallel to the axial direction of the first magnet 331. The vibration direction of the second diaphragm 342 is parallel to the axial direction of the second magnet 341. In some embodiments, the axial direction of the first magnet 331 and the axial direction of the second magnet 341 can form a certain angle. For example, 1°, 5°, 10°, 30°, etc. In this case, the vibration direction of the first diaphragm 332 and the vibration direction of the second diaphragm 342 also form a corresponding angle. The magnets (first magnet 331 and second magnet 341) have a south pole (S pole) and a north pole (N pole). The axial direction of the magnet can refer to the polarization direction of the magnet, or the direction of the axis of symmetry of the magnet structure.

[0094] In some embodiments, the same-named magnetic poles of the first magnet 331 and the second magnet 341 are arranged opposite each other. For example, as shown in FIG5A, the N pole of the first magnet 331 is arranged opposite to the N pole of the second magnet 341. In other embodiments, the S pole of the first magnet 331 is arranged opposite to the S pole of the second magnet 341. In this case, the first magnet 331 and the second magnet 341 exhibit a repulsive force, and the first magnetic field and the second magnetic field are coupled together, meaning that the second magnetic field generated by the second magnet 341 affects the distribution of the first magnetic field generated by the first magnet 331. For example, compared to the case where only the first magnet 331 is provided (as shown in Figure 5B, which illustrates the magnetic field lines when only the first magnet 331 is provided), in the structure shown in Figure 5A, referring to the magnetic field lines shown in Figure 5A, the second magnet 341 can suppress the diffusion of the magnetic field lines radiated into space by the first magnet 331, so that more magnetic field lines diffusing into space from the N pole of the first magnet 331 are "restricted" to the vicinity of the first coil, thereby increasing the magnetic field strength at the first coil of the first speaker 330 and thus improving the sensitivity of the first speaker 330; at the same time, the first magnetic field generated by the first magnet 331 will also affect the distribution of the second magnetic field generated by the second magnet 341, thereby increasing the magnetic field strength at the second coil of the second speaker 340 and thus improving the sensitivity of the second speaker 340.

[0095] In the embodiment shown in Figure 5A, the repulsive force between the first magnet 331 and the second magnet 341 should be greater than 0.08N. The method for testing the repulsive force between the first magnet 331 and the second magnet 341 is as follows: First, a fixture is made to fix the first magnet 331 and the second magnet 341 according to their actual distance and relative position; then, one of the magnets 331 and 341 is connected to a spring balance, and the fixture is removed, and the force count value is observed; finally, the repulsive force between the first magnet 331 and the second magnet 341 is determined based on the force count value.

[0096] In some embodiments, the axis of the first magnet 331 and the axis of the second magnet 341 can be spaced apart. As shown in FIG5A, the axis of the first magnet 331 is a1, and the axis of the second magnet 341 is a2. The spaced-apart arrangement of a1 and a2 can be understood as the two not coinciding. The axis a1 of the first magnet 331 and the axis a2 of the second magnet 341 are parallel and spaced apart. By setting the axis a1 of the first magnet 331 to be parallel to the axis a2 of the second magnet 341, the leakage magnetic field suppression effect of the second magnet 341 on the first magnet 331 can be improved, that is, the limiting effect of the second magnet 341 on the magnetic field lines emitted by the first magnet 341 can be improved, and the magnetic induction intensity at the first coil of the first speaker 330 can be increased. By setting the axis a1 of the first magnet 331 and the axis a2 of the second magnet 341 at an interval, the second speaker 340 can avoid the area in the first vibration direction where the first diaphragm 332 is closest to the second speaker 340, that is, the central area of ​​the first diaphragm 332 (such as the dome of the first diaphragm 332 as described later), ensuring that the first diaphragm 332 will not touch the second speaker 340 during vibration (i.e., the second speaker 340 will not affect the vibration of the first diaphragm 332). Based on this, the distance between the second speaker 340 and the first speaker 30 can be further reduced, thereby increasing the coupling between the first magnet 331 and the second magnet 341 and reducing the overall size of the acoustic output device 300.

[0097] Figure 6A is an exemplary wearing diagram of an acoustic output device according to some embodiments of this specification. As shown in Figure 6A, in some embodiments, in the wearing state, at least a portion of the housing 310 can extend into the concha cavity of the ear, and at least a portion of the side of the housing 310 abuts against the concha cavity. In some embodiments, the housing 310 may have a connecting end CE connected to the support structure 320 and a free end FE not connected to the support structure 320. For example, referring to Figure 6A, in the wearing state, the free end FE of the housing 310 can extend into the concha cavity. Optionally, the housing 310 and the support structure 320 may be configured to jointly clamp the ear region from both the front and rear sides of the ear region corresponding to the concha cavity, thereby increasing the resistance to the acoustic output device 300 falling off the ear, and thus improving the stability of the acoustic output device 300 in the wearing state. For example, the free end FE of the housing 310 is pressed into the concha cavity in the thickness direction X. For example, the free end FE abuts against the concha cavity in the major axis direction Y and / or the minor axis direction Z (e.g., abuts against the inner wall of the opposite free end FE of the concha cavity). Here, the free end FE of the housing 310 refers to the end of the housing 310 that is positioned opposite the fixed end connected to the support structure 320. The housing 310 can be a regular or irregular structure. Here, for further explanation of the free end FE of the housing 310, an exemplary description is provided. For example, when the housing 310 is a cuboid structure, the end wall of the housing 310 is a plane, and in this case, the free end FE of the housing 310 is the end sidewall of the housing 310 positioned opposite the fixed end connected to the support structure 320. As another example, when the housing 310 is a sphere, ellipsoid, or an irregular structure, the free end FE of the housing 310 can refer to a specific region away from the fixed end obtained by cutting along the YZ plane (the plane formed by the minor axis direction Z and the thickness direction X) of the housing 310. It should be noted that, when worn, the free end FE of the shell 310 can not only extend into the concha, but also project orthogonally onto the antihelix, or onto the left and right sides of the head, positioned in front of the ear on the sagittal axis. In other words, the support structure 320 can support the shell 310 when worn in the concha, antihelix, or in front of the ear.

[0098] The acoustic output device 300 shown in Figure 6A will be used as an example to describe the acoustic output device 300 in detail below. It should be noted that, without violating the corresponding acoustic principles, the structure and corresponding parameters of the acoustic output device 300 in Figure 6A can also be applied to other acoustic output devices of the configuration mentioned in this article.

[0099] By extending at least a portion of the housing 310 into the concha cavity, the listening volume (especially high-frequency listening volume) at the listening position (e.g., at the ear canal opening) can be increased while still maintaining a good far-field leakage cancellation effect. As an example only, when the entire or part of the structure of the housing 310 extends into the concha cavity, the housing 310 and the concha cavity form a cavity-like structure (hereinafter referred to as a cavity-like structure). In the embodiments described, the cavity-like structure can be understood as a semi-enclosed structure formed by the sidewalls of the housing 310 and the concha cavity structure. This semi-enclosed structure ensures that the interior is not completely sealed off from the external environment, but rather has a leakage structure (e.g., openings, gaps, channels, etc.) that acoustically communicates with the external environment. When the user wears the acoustic output device 300, one or more sound outlet holes may be provided on the side of the housing 310 of the acoustic output device 300 near or facing the user's ear canal, and one or more pressure relief holes may be provided on other sidewalls of the housing (e.g., sidewalls away from or opposite to the user's ear canal). For example, when the housing 310 has one sound outlet, the first speaker 330 and the second speaker 340 share the same sound outlet. As another example, when the housing 310 has two sound outlets, one outlet is used to output high-frequency sounds, and the other outlet is used to output low-frequency or mid-low-frequency sounds. As yet another example, when the housing 310 has two or more sound outlets, some outlets are used to output high-frequency sounds, and others are used to output low-frequency or mid-low-frequency sounds. Taking the housing 310, which includes a sound outlet and a pressure relief hole, as an example, the sound outlet is acoustically coupled to the front cavity of the acoustic output device 300, and the pressure relief hole is acoustically coupled to the rear cavity of the acoustic output device 300. The sound output from the sound outlet and the sound output from the pressure relief hole can be approximated as two sound sources with opposite phases. The inner walls of the housing 310 and the concha cavity form a cavity-like structure, wherein the sound source corresponding to the sound outlet is located inside the cavity-like structure, and the sound source corresponding to the pressure relief hole is located outside the cavity-like structure, forming the acoustic model shown in Figure 6B.

[0100] Figure 6B is an exemplary distribution diagram of a cavity structure surrounding one of the sound sources in a dual-sound-source configuration according to some embodiments of this specification. As shown in Figure 6B, the cavity-like structure 502 may include a listening position and at least one sound source 501A. Here, "including" can mean that at least one of the listening position and the sound source 501A is inside the cavity-like structure 502, or that at least one of the listening position and the sound source 501A is at the inner edge of the cavity-like structure 502. The listening position can be equivalent to the entrance of the ear canal, or it can be an acoustic reference point of the ear, such as an ear reference point (ERP), ear-drum reference point (DRP), or an entrance structure guiding the listener. Since the sound source 501A is enclosed by the cavity-like structure 502, most of the sound radiated from it will reach the listening position through direct or reflected sound. Conversely, without the cavity-like structure 502, most of the sound radiated from the sound source 501A will not reach the listening position. Therefore, the cavity structure significantly increases the volume of the sound reaching the listening position. Simultaneously, only a small portion of the anti-phase sound radiated from the anti-phase sound source 501B outside the cavity structure 502 enters the cavity structure 502 through the leakage structure 503. This is equivalent to generating a secondary sound source 501B' at the leakage structure 503, whose intensity is significantly less than that of sound source 501B and also significantly less than that of sound source 501A. The sound generated by the secondary sound source 501B' has a weak anti-phase canceling effect on sound source 501A within the cavity, resulting in a significant increase in the listening volume at the listening position. Regarding sound leakage, the sound source 501A radiating sound to the outside through the leakage structure 503 of the cavity is equivalent to generating a secondary sound source 501A' at the leakage structure 503. Since almost all the sound radiated by the sound source 501A is output from the leakage structure 503, and the scale of the cavity-like structure 502 is much smaller than the spatial scale for evaluating sound leakage (difference of at least one order of magnitude), the intensity of the secondary sound source 501A' can be considered equivalent to that of the sound source 501A. For the external space, the secondary sound source 501A' and the sound source 501B form a dual-source cancellation mechanism to reduce sound leakage.

[0101] In specific application scenarios, the outer wall of the housing 310 is usually flat or curved, while the contour of the user's concha 102 is an uneven structure. By extending part or all of the housing 310 into the concha, a cavity-like structure communicating with the outside is formed between the housing 310 and the contour of the concha. Furthermore, by setting the sound outlet hole on the housing 310 facing the user's ear canal opening and near the edge of the concha 102, and setting the pressure relief hole on the housing 310 away from or away from the ear canal opening, the acoustic model shown in Figure 6B can be constructed. This allows the user to improve the listening position at the ear opening and reduce far-field sound leakage when wearing the acoustic output device 300.

[0102] In some embodiments, a first sound outlet and a second sound outlet may be provided on the inner surface of the housing 310. In the wearing configuration shown in FIG. 6A, the inner surface of the housing 310 refers to the side of the housing 310 facing the ear canal opening when worn. The first sound outlet is acoustically coupled to the first diaphragm 332. When the first diaphragm 332 vibrates, the sound generated on the side of the first diaphragm 332 facing away from the first magnet 331 is radiated outward through the first front cavity and the first sound outlet. The second sound outlet is acoustically coupled to the second diaphragm 342. When the second diaphragm 342 vibrates, the sound generated on the side of the second diaphragm 342 facing away from the second magnet 341 is radiated outward through the second front cavity and the second sound outlet. In some embodiments, the first front cavity of the first speaker 330 and the second front cavity of the second speaker 340 are not acoustically connected, and the first speaker 330 and the second speaker 340 do not share a sound outlet. That is, the first sound outlet is only used to radiate low-frequency or mid-low-frequency sounds generated when the first diaphragm 332 vibrates, and the second sound outlet is only used to radiate high-frequency sounds generated when the second diaphragm 342 vibrates. By providing the first and second sound outlets on the inner side of the housing 310, and radiating the sound generated by the first speaker 330 through the first sound outlet and the sound generated by the second speaker 340 through the second sound outlet (i.e., the two speakers do not share a sound outlet), the structure of the outer side of the second speaker can be simplified (e.g., the thickness of the housing 310 can be reduced). This is because, normally, the second speaker 340 is a packaged structure, with the entire second speaker 340 housed within the first front cavity of the first speaker 330. If the first speaker 330 and the second speaker 340 need to share a sound outlet, it's equivalent to placing the first sound outlet outside the second sound outlet (both speakers need to radiate sound outward through the first sound outlet, which is a shared sound outlet). Compared to the arrangement where the first and second sound outlets are staggered on the inner side of the housing 310 when they don't share a sound outlet, sharing a sound outlet results in a larger overall size for the acoustic output device 300 (especially the thickness of the housing 310). Furthermore, not sharing a sound outlet prevents the sound radiated by the first speaker 330 and the second speaker 340 from interfering with each other, thereby reducing mutual radiation impedance.

[0103] In some embodiments, a pressure relief hole may be provided on the housing 310, and the pressure relief hole is acoustically coupled to the first diaphragm 332. When the first diaphragm 332 vibrates, the sound generated on the side of the first diaphragm 332 facing the first magnet 331 is radiated outward through the first rear cavity and the pressure relief hole. In some embodiments, the pressure relief hole may be located on the side of the housing 310 adjacent to or opposite to the inner side. In some embodiments, the first speaker 330 outputs low-frequency sound, and the amplitude of the first diaphragm 332 when vibrating is large, which will result in high sound pressure in the first front cavity and the first rear cavity of the first speaker 330. By providing a pressure relief hole on the housing 310, the pressure relief hole can be used to balance the sound pressure in the first front cavity and the first rear cavity, so as to ensure that the gas in the first rear cavity does not hinder the vibration of the first diaphragm 332, thereby ensuring that the first speaker 330 can effectively output low-frequency sound.

[0104] In some embodiments, the inner cavity formed by the housing 310 may include a first cavity and a second cavity separated from each other, with a first speaker 330 housed in the first cavity and a second speaker 340 housed in the second cavity. In some embodiments, a partition may be provided inside the housing 310, dividing the inner cavity formed by the housing 310 into a first cavity housing the first speaker 330 and a second cavity housing the second speaker 340. In this case, the first diaphragm 332 of the first speaker 330 divides the first cavity into a first front cavity and a first rear cavity. The first front cavity is acoustically coupled to a first sound outlet, and sound generated on the front side of the first diaphragm 332 is radiated outward through the first front cavity and the first sound outlet. The second diaphragm 342 of the second speaker 340 divides the second cavity into a second front cavity and a second rear cavity. The second front cavity is acoustically coupled to a second sound outlet, and sound generated on the front side of the second diaphragm 342 is radiated outward through the second front cavity and the second sound outlet. Optionally, the partition may be a circuit board carrying electronic components in the second speaker 340 or a magnetic conductive element in a magnetic circuit assembly. The first speaker 330 and the second speaker 340 do not share the same cavity. That is, there is no acoustic connection between the first diaphragm 332 and the second diaphragm 342 (i.e., the first front cavity of the first speaker 330 and the second front cavity of the second speaker 340 are not acoustically connected, and the first speaker 330 and the second speaker 340 do not share the same sound outlet). This arrangement can prevent the sound radiated by the first speaker 330 and the second speaker 340 from interfering with each other, thereby reducing mutual radiation impedance.

[0105] In some embodiments, when worn, the second sound outlet can be closer to the ear canal opening than the first sound outlet; that is, the sound outlet corresponding to the high-frequency speaker is closer to the ear canal opening. As an example only, when worn, the orthographic projection of the centroid of the second sound outlet onto the sagittal plane of the human body is closer to the ear canal opening than the orthographic projection of the centroid of the first sound outlet onto the sagittal plane of the human body. Orthographic projection refers to the projection obtained by projecting along a projection direction perpendicular to the projection plane. Corresponding to this embodiment, the projection plane here is the sagittal plane of the human body, and the projection direction is the coronal axis direction. Given that the high-frequency sound output by the second speaker 340 has strong directivity, by placing the second sound outlet closer to the ear canal opening, the listening volume of the high-frequency sound output by the second speaker can be increased, thereby improving the sound effect of the acoustic output device 300. In some embodiments, the first sound outlet can be arranged around the second sound outlet to ensure that the acoustic output device 300 can output full-frequency sound.

[0106] It should be noted that since the first and second sound outlets are located on the housing, and each sidewall of the housing has a certain thickness, both the first and second sound outlets are holes with a certain depth. Therefore, both the first and second sound outlets can have internal and external openings. For ease of description, in the embodiments of this specification, the centroids of the first and second sound outlets can indicate the centroid of the external opening of the sound outlet.

[0107] In some embodiments, when worn, the center of the second magnet 341 may be closer to the ear canal opening than the center of the first magnet 331. As an example only, when worn, the orthographic projection of the center of the second magnet 341 onto the sagittal plane of the human body is closer to the ear canal opening than the orthographic projection of the center of the first magnet 331 onto the sagittal plane of the human body. The center of the magnet refers to the centroid of the end face of the magnet facing the diaphragm. By setting the center of the second magnet 341 closer to the ear canal opening, the sound output by the second diaphragm 342 of the second speaker can reach the ear canal opening after traveling a shorter distance, thereby increasing the listening volume of the high-frequency sound output by the second speaker and improving the sound effect of the acoustic output device 300.

[0108] By setting the relative positions of the first magnet 331 and the second magnet 341 in a direction perpendicular to the vibration direction of the diaphragm (e.g., the horizontal direction shown in FIG. 5A), the magnetic field coupling relationship between the first magnet 331 and the second magnet 341 can be guaranteed to enhance the magnetic induction intensity at the first coil in the first loudspeaker, thereby increasing the radiated sound pressure level of the first loudspeaker. Specifically, in some embodiments, on the plane where the surface of the first magnet 331 faces the first diaphragm 332 (i.e., on the reference plane perpendicular to the vibration direction of the first diaphragm 332), the orthographic projection of the second magnet 341 at least partially overlaps with the orthographic projection of the first magnet 331, such that the second magnetic field generated by the second magnet 341 can enhance the magnetic induction intensity at the first coil located in the first magnetic field generated by the first magnet 331. That is, the second magnetic field generated by the second loudspeaker 340 enhances the first magnetic field generated by the first loudspeaker 330, thereby increasing the sound pressure level of the low-frequency sound output by the first loudspeaker 330. Furthermore, as shown in Figure 7D, the average magnetic flux density at the first coil changes with the horizontal movement distance of the second speaker 340 (as described in Figure 5A). Therefore, the size of the overlapping area between the orthographic projections of the second magnet 341 and the first magnet 331 affects the average magnetic flux density at the first coil. The larger the overlapping area (the maximum value is equal to the area of ​​the larger of the orthographic projection areas of the first magnet 331 and the second magnet 341), the greater the average magnetic flux density at the first coil. For a more detailed explanation of Figure 7D, please refer to the following text.

[0109] The relative positions of the first diaphragm 332 and the second diaphragm 342 in a direction perpendicular to the vibration direction (e.g., the horizontal direction shown in FIG. 5A) determine the relative positions of the first magnet 331 and the second magnet 341, thereby affecting the coupling between the first magnetic field generated by the first speaker 330 and the second magnetic field generated by the second speaker 340. Specifically, in some embodiments, on the plane where the surface of the first magnet 331 faces the first diaphragm 332 (i.e., on the reference plane perpendicular to the vibration direction of the first diaphragm 332), the orthographic projection of the second diaphragm 342 at least partially overlaps with the orthographic projection of the first diaphragm 332. At this time, the distance between the first diaphragm 332 and the second diaphragm 342 in a direction perpendicular to the vibration direction is not too far, so that the second magnetic field generated by the second magnet can enhance the magnetic induction intensity at the first coil located in the first magnetic field generated by the first magnet. That is, the second magnetic field generated by the second speaker 340 enhances the first magnetic field generated by the first speaker, thereby increasing the sound pressure level of the low-frequency sound output by the first speaker 340. The plane on which the surface of the first magnet 331 faces the first diaphragm 332 can be regarded as the projection plane of the first diaphragm 332 and the second diaphragm 342.

[0110] In some embodiments, the plane on which the surface of the first magnet 331 faces the first diaphragm 332 can be determined based on a three-dimensional model of the acoustic output device, and an orthographic projection can be made on that plane, thereby determining the positional relationship between the orthographic projection of the first magnet 331 and the orthographic projection of the second magnet 341.

[0111] Referring to Figure 4, in some embodiments, the first diaphragm 332 may include a main body region 3321 and a surrounding loop region 3322. The main body region 3321 is fixedly connected to the first speaker 330 via the surrounding loop region 3322. In some embodiments, the main body region 3321 may include an arched dome 3321c. The arched dome 3321c protrudes towards the side away from the first magnet 331. The arched dome 3321c has high strength and stiffness, which to some extent suppresses the segmented vibration of the main body region 3321, thereby improving the vibration characteristics of the first speaker 330.

[0112] In some embodiments, the dome 3321c and the loop region 3322 can be directly connected. For example, the loop region 3322 may include an inner edge near the dome 3321c and an outer edge away from the dome 3321c, with the dome 3321c directly connected to the inner edge. In some embodiments, the dome 3321c and the loop region 3322 can be indirectly connected. For example, the main body region 3321 may further include a first inclined segment 3321a and a first connecting segment 3321b. The first inclined segment 3321a connects the main body region 3321 and the loop region 3322. The first connecting segment 3321b connects the first inclined segment 3321a and the dome 3321c. The first connecting segment 3321b is used to connect the first coil 333, and the extending direction of the first connecting segment 3321b is perpendicular to the vibration direction of the first diaphragm 332. The first inclined segment 3321a is in contact with a portion of the loop region 3322. The first coil 333 is located below the first connecting section 3321b, and the first inclined section 3321a is inclined away from the first coil 333 relative to the first connecting section 3321b. This arrangement prevents adhesive used for bonding the first coil 333 to the first diaphragm 332 from overflowing into the loop area 3322, thus avoiding corrosion of the loop area 3322 and affecting the vibration performance of the first diaphragm 332.

[0113] In some embodiments, the projection of the center of the second magnet 341 of the second loudspeaker 340 onto the first diaphragm 332 along its axial direction can be located between the center of the dome 3321c and the inner edge of the surround region 3322. The center of the dome 3321c can refer to the centroid of the dome 3321c. As an example, the center of the dome 3321c can be located at the highest point of the dome 3321c (i.e., the point on the dome 3321c farthest from the first magnet 331). By setting the relative positions of the first magnet 331 and the second magnet 341 along the vibration direction perpendicular to the diaphragm (i.e., the projection of the center of the second magnet 341 along its axial direction onto the first diaphragm 332 is located between the center of the dome 3321c and the inner edge of the surround region 3322), it can be ensured that the first magnetic field and the second magnetic field can reinforce each other, thereby increasing the radiated sound pressure level of the two loudspeakers. Furthermore, since the central region of the dome 3321c and the surround region 3322 are both relatively high areas on the first diaphragm 322, by positioning the projection of the center of the second magnet 341 along its axial direction onto the first diaphragm 332 between the center of the dome 3321c and the inner edge of the surround region 3322, the second speaker 340 can be offset from the two higher regions (i.e., the center of the dome 3321c and the surround region 3322), thereby reducing the distance between the first speaker 330 and the second speaker 340, and thus reducing the overall size of the acoustic output device 300. In addition, this arrangement also prevents the first diaphragm (especially the dome 3321c) from impacting the second speaker when it vibrates.

[0114] In some embodiments, the magnetic circuit system containing the first magnet 331 and the magnetic circuit system containing the second magnet 341 have a first distance along the vibration direction of the first diaphragm 332. Here, the magnetic circuit system can refer to the magnetic circuit assembly mentioned above. The first distance refers to the distance between the bottom of the magnetic circuit system of the second speaker 340 facing away from the second diaphragm 342 (e.g., the surface of the second magnet 341 facing away from the second diaphragm 342) and the top of the magnetic circuit system of the first speaker 330 (e.g., the surface of the magnetic guide plate in the magnetic circuit assembly facing the first diaphragm 332).

[0115] In some embodiments, to ensure that the second speaker 340 does not collide with the first diaphragm 332 during vibration, the first distance can be greater than 2.85 mm. In some embodiments, to ensure that the size of the acoustic output device 300 is not too large, the first distance can be less than 3.42 mm. In some embodiments, to balance the vibration of the first diaphragm and the size of the acoustic output device, the first distance can be 2.85 mm to 3.42 mm. In some embodiments, the first distance affects the coupling between the first magnetic field generated by the first speaker 330 and the second magnetic field generated by the second speaker 340. By setting the first distance within a suitable range, it can be ensured that the first magnetic field and the second magnetic field can reinforce each other, thereby increasing the radiated sound pressure level of the two speakers. In some embodiments, to ensure that the first magnetic field and the second magnetic field can reinforce each other to increase the radiated sound pressure level of the two speakers, while ensuring stable vibration of the first diaphragm 332, the first distance can be 3 mm to 3.2 mm.

[0116] In some embodiments, the first magnet 331 and the second magnet 341 have a second distance along the vibration direction of the first diaphragm 332. As an example, the second distance may be the distance between the bottom of the second magnet 341 (the side of the second magnet 341 facing away from the second diaphragm 342) and the top of the first magnet 331 (the side of the first magnet 331 facing the first diaphragm 332).

[0117] In some embodiments, the second distance affects the coupling between the first magnetic field generated by the first speaker 330 and the second magnetic field generated by the second speaker 340. By setting the second distance within a suitable range, it can be ensured that the first and second magnetic fields can reinforce each other, thereby increasing the radiated sound pressure level of the two speakers. In some embodiments, to ensure that the first and second magnetic fields can reinforce each other and increase the radiated sound pressure level of the two speakers, the second distance can be 3.06mm-4.58mm. In some embodiments, the second distance can be 3.6mm-4.0mm. In some embodiments, the second distance can be 3.80mm-3.85mm.

[0118] In some embodiments, the relative positions of the first loudspeaker 330 and the second loudspeaker 340 in the horizontal direction (i.e., the direction perpendicular to the vibration direction) affect the coupling between the first magnetic field and the second magnetic field, thereby affecting the magnetic flux density at the first coil of the first loudspeaker 330 and the second coil of the second loudspeaker 340. Figure 7A is a schematic diagram showing the first loudspeaker and the second loudspeaker with different relative positions in the horizontal direction according to some embodiments of this specification. Figure 7B is a schematic diagram of the magnetic field distribution of the first loudspeaker and the second loudspeaker according to some embodiments of this specification. Figure 7C is a graph showing the trend of magnetic flux density at the endpoint of the first coil of the first loudspeaker when the first loudspeaker and the second loudspeaker have different relative positions in the horizontal direction according to some embodiments of this specification. Figure 7D is a graph showing the trend of average magnetic flux density at the first coil according to some embodiments of this specification. It should be noted that Figures 7A, 7B, 7C, and 7D illustrate a second speaker 340 with a dual-magnet configuration (i.e., including a second magnet 341 and a third magnet 343; for details on the dual-magnet configuration, please refer to the relevant description in Figure 8). However, regardless of whether the second speaker 340 has a single-magnet structure (i.e., only including the second magnet 341) or a dual-magnet configuration, similar conclusions can be drawn regarding the relative horizontal positions of the first speaker 330 and the second speaker 340. As shown in Figure 7A, with the spacing between the second speaker 340 and the first speaker 330 along the vibration direction of the first diaphragm 332 remaining constant, Figure 7A(a) shows the positional relationship of the second speaker 340 located outside the first speaker 330 along the direction perpendicular to the vibration direction of the first diaphragm 332. In Figure 7A(a), the distance between the first end 3301 of the first speaker 330 and the second end 3401 of the second speaker 340 is 0. In this figure, the first end 3301 is the end of the first speaker 330 that is closest to the second speaker 340, and similarly, the second end 3401 is the end of the second speaker 340 that is closest to the first speaker 330. At this time, on a reference plane perpendicular to the vibration direction of the first diaphragm 332, the projections of the second speaker 340 and the first speaker 330 do not overlap, which can be understood as the case where the second speaker moves 0 mm in Figure 7C. Figure 7A(b) shows the positional relationship of the second speaker 340 directly opposite the center of the first speaker 330 on a reference plane perpendicular to the vibration direction of the first diaphragm 332. At this time, the distance between the first end 3301 and the second end 3401 increases.Referring to Figures 7A-7C, when the second speaker 340 is located outside the first speaker 330, the direction of the magnetic field lines of the side magnet of the second speaker 340 (i.e., the third magnet 343) is opposite to the direction of the magnetic field lines of the first magnetic field generated by the first speaker 330 at the endpoint of the first coil. Therefore, as the second speaker 340 moves towards the center of the first speaker 330, the magnetic flux density at the endpoint of the first coil of the first speaker 330 decreases. As the second speaker 340 continues to move, the direction of the side magnet of the second speaker 340 at the first coil of the first speaker 330 is opposite to the initial direction. Therefore, as the moving distance of the second speaker 340 increases, the magnetic flux density at the endpoint of the first coil increases. When the second speaker 340 moves to a position directly opposite the center of the first speaker 330, the average magnetic flux density at the first coil is at its maximum.

[0119] Referring to Figure 7D, which illustrates the relationship between the average magnetic flux density at the first coil and the horizontal movement distance of the second speaker 340, the horizontal axis represents the movement distance d of the second speaker 340 in mm, and the vertical axis represents the average magnetic flux density at the first coil in T. The movement of the second speaker 340 can be a process from position (a) to position (b) in Figure 7A. When the movement distance of the second speaker 340 is less than approximately 4 mm, the change in the average magnetic flux density at the first coil is not significant. This is because the second speaker 340 has two opposing magnetic fields in the horizontal direction (see Figure 7B), both of which affect the magnetic flux density at the endpoint of the first coil. When the movement distance of the second speaker 340 is small, the effects of the two magnetic fields are essentially the same, thus canceling each other out, and the average magnetic flux density at the first coil remains essentially unchanged. As the second speaker 340 moves a greater distance (greater than 4mm), it gets closer to the center of the first speaker 330. The side magnet of the second speaker 340 enhances the magnetic field at the first coil, and the average magnetic induction intensity at the first coil increases at a faster rate and with a greater magnitude.

[0120] It should be noted that, in principle, the average magnetic induction intensity at the first coil is greatest when the second speaker 340 is located at the center of the first speaker 330. However, in practical applications, considering factors such as the size of the acoustic output device 300, the distance between the second sound outlet of the second speaker 340 and the ear canal opening, and the magnetic field strength, the position directly opposite the center of the first speaker 330 may not be the optimal position for the second speaker 340. For example, in the structure and wearing state shown in Figure 6A, the position directly opposite the center of the first speaker 330 shown in Figure 7A(b) is farther from the ear canal opening and is at risk of being blocked by the tragus.

[0121] In some embodiments, the relative horizontal position of the second speaker 340 and the first speaker 330 can be characterized by the distance between the orthographic projection of the centroid of the first diaphragm 332 and the orthographic projection of the centroid of the second diaphragm 342 on the plane containing the surface of the first magnet 331 facing the first diaphragm 332. In conjunction with the above, to balance the average magnetic induction intensity at the first coil, the size of the acoustic output device 300, and the distance between the second sound outlet of the second speaker 340 and the ear canal opening, the distance between the orthographic projection of the centroid of the first diaphragm 332 and the orthographic projection of the centroid of the second diaphragm 342 on the plane containing the surface of the first magnet 331 facing the first diaphragm 332 can be 0mm-8mm.

[0122] Figure 8 is an exemplary structural diagram of a second loudspeaker according to some embodiments of this specification. Referring to Figure 8, in some embodiments, the second loudspeaker 340 may further include a third magnet 343 disposed around the second magnet 341. For example, the third magnet 343 may be a ring magnet disposed around the periphery of the second magnet 341.

[0123] In some embodiments, the third magnet 343 can be configured to have opposite magnetic poles to the second magnet 341. For example, as shown in FIG8, the N pole of the second magnet 341 faces the second diaphragm 342, while the S pole of the third magnet 343 faces the second diaphragm 342. In this configuration, on the one hand, the magnetic field generated by the third magnet 343 can increase the magnetic field strength at the second coil of the second speaker 340; on the other hand, more magnetic field lines emitted by the N pole of the second magnet 341 can be received by the S pole of the third magnet 343, that is, the third magnet 343 can increase the magnetic field strength of the second magnet 341 at the second coil.

[0124] Figure 9 is another exemplary structural diagram of a second loudspeaker according to some embodiments of this specification. Referring to Figure 9, in some embodiments, the second loudspeaker 340 may further include a fourth magnet 344, which is arranged along the vibration direction of the second diaphragm 342 with the second magnet 341, and the same magnetic poles of the fourth magnet 344 and the second magnet 341 are arranged opposite each other. As shown in Figure 9, the N pole of the fourth magnet 344 is arranged opposite to the N pole of the second magnet 341. In this arrangement, more magnetic field lines can pass perpendicularly through the second coil, increasing the magnetic induction intensity at the second coil and suppressing magnetic leakage, thereby increasing the sensitivity of the second loudspeaker 340. It should be noted that when the second loudspeaker 340 includes the fourth magnet 344, the configuration (e.g., the diameter of the magnets) of its second magnet 341 and third magnet 343 is the same as when the second loudspeaker 340 includes only the second magnet 341 and the third magnet 343.

[0125] Figure 10 is a sound pressure level (SPL) curve diagram of a second loudspeaker with a dual-magnet and a triple-magnet configuration according to some embodiments of this specification. A dual-magnet configuration refers to a configuration where the second loudspeaker 340 includes two magnets; for example, the second loudspeaker 340 shown in Figure 8 above includes a second magnet 341 and a third magnet 343. A triple-magnet configuration refers to a configuration where the second loudspeaker 340 includes three magnets; for example, the second loudspeaker 340 shown in Figure 9 above includes a second magnet 341, a third magnet 343, and a fourth magnet 344. In Figure 10, the horizontal axis represents frequency in Hz, and the vertical axis represents sound pressure level in dB. Curve 1010 represents the SPL curve of the second loudspeaker with a dual-magnet configuration (second and third magnets), and curve 1020 represents the SPL curve of the second loudspeaker with a triple-magnet configuration (second, third, and fourth magnets). As shown in Figure 10, the three-magnet second speaker exhibits higher sensitivity across the entire frequency range compared to the two-magnet configuration. The sensitivity of the three-magnet second speaker is approximately 6 dB higher than that of the two-magnet configuration. In other words, compared to the case without the fourth magnet 344 (i.e., the two-magnet configuration), by configuring the fourth magnet 344 as described above (i.e., the three-magnet configuration), more magnetic field lines pass perpendicularly through the second coil, increasing the magnetic flux density at the second coil and suppressing magnetic leakage, thereby improving the sensitivity of the second speaker.

[0126] In some embodiments, when the first magnet 331 of the first speaker 330 and the second magnet 341 of the second speaker 340 are opposite to each other, and a third magnet 343 is arranged around the second magnet 341, the magnetic field generated by the second magnet 341 can enhance the magnetic induction intensity at the first coil of the first speaker 330, while the magnetic field generated by the third magnet 343 will reduce the magnetic induction intensity at the first coil. Since the second magnet 341 and the third magnet 343 have opposite effects on the magnetic induction intensity at the first coil, it is necessary to reasonably set the dimensions of the second magnet 341 and the third magnet 343 to ensure the output performance of the second speaker 340 itself, while the combined magnetic field of the second speaker 340 (e.g., the magnetic field obtained after coupling the magnetic field generated by the second magnet 341 and the magnetic field generated by the third magnet 343) can enhance the magnetic induction intensity at the first coil. In this embodiment, the size of the magnet can be characterized by the area of ​​the cross-section of the magnet along the direction perpendicular to its axis. For ease of description, the ratio of the area of ​​the cross section of the second magnet 341 along its axial direction to the area of ​​the cross section of the third magnet 343 along its axial direction is simply referred to as the area ratio of the second magnet to the third magnet.

[0127] Figure 11A is a schematic diagram of the structure of the second and third magnets according to some embodiments of this specification, and Figure 11B is a schematic diagram of the structure of the second and third magnets according to other embodiments of this specification. In Figure 11A, the ratio of the area of ​​the cross-section of the second magnet 341 along its axial direction to the area of ​​the cross-section of the third magnet 343 along its axial direction is 0.1. In Figure 11B, the ratio of the area of ​​the cross-section of the second magnet 341 along its axial direction to the area of ​​the cross-section of the third magnet 343 along its axial direction is 4. Figure 11C is a graph showing the effect of the area ratio of the second magnet 341 to the third magnet 343 according to some embodiments of this specification on the magnetic induction intensity at the first coil. The horizontal axis represents the area ratio of the second magnet 341 to the third magnet 343, and the vertical axis represents the magnetic induction intensity at the first coil. As can be seen from Figure 11C, as the area ratio of the second magnet 341 to the third magnet 343 increases, the magnetic induction intensity at the first coil increases. Based on this, in some embodiments, in order to increase the magnetic induction intensity at the first coil and thus increase the sound pressure level of the first speaker 330, the ratio of the area of ​​the cross section of the second magnet 341 along its axial direction to the area of ​​the cross section of the third magnet 343 along its axial direction can be 0.1-4.

[0128] In some embodiments, in order to ensure the performance of the second speaker 340, the ratio of the area of ​​the cross section of the second magnet 341 along the direction perpendicular to the axis of the second magnet 341 to the area of ​​the cross section of the third magnet 343 along the direction perpendicular to the axis of the third magnet 343 can be 0.4-0.6.

[0129] In some embodiments, the magnetic flux density at any position on the first coil of the first speaker 330 is greater than 0.45T; and the magnetic flux density at any position on the second coil of the second speaker 340 is greater than 0.3T. This allows both the first speaker 330 and the second speaker 340 to output sounds with higher sound pressure levels, thereby increasing the user's listening volume. In some embodiments, to further increase the sound pressure levels of the first speaker 330 and the second speaker 340, the magnetic flux density at any position on the first coil of the first speaker 330 is greater than 0.56T; and the magnetic flux density at any position on the second coil of the second speaker 340 is greater than 0.54T.

[0130] Figure 12 is another structural diagram of an acoustic output device according to some embodiments of this specification. As shown in Figure 12, the acoustic output device 1200 includes a housing, a support structure, a first speaker 1230, and a second speaker 1240. The housing and support structure of the acoustic output device 1200 are substantially the same as those of the housing 310 and support structure 320 of the acoustic output device 300, respectively. The structure and acoustic principle of the first speaker 1230 and the second speaker 1240 of the acoustic output device 1200 are also substantially the same as those of the first speaker 330 and the second speaker 340 of the acoustic output device 300. For example, the first speaker 1230 includes a first magnet 1231 and a first diaphragm, the first magnet 1231 and the first diaphragm being spaced apart along the vibration direction of the first diaphragm (as shown in the figure, the first vibration direction), and the second speaker 1240 includes a second magnet 1241 and a second diaphragm, the second magnet 1241 and the second diaphragm being spaced apart along the vibration direction of the second diaphragm (as shown in the figure, the second vibration direction). For example, the first loudspeaker 1230 includes a first coil connected to a first diaphragm and at least partially located in the magnetic field formed by the first magnet 1231. When the first coil is energized, it drives the first diaphragm to vibrate to produce sound. The second loudspeaker 1240 includes a second coil connected to a second diaphragm and at least partially located in the magnetic field formed by the second magnet 1241. When the second coil is energized, it drives the second diaphragm to vibrate to produce sound. The difference is that in the acoustic output device 1200, the axis of the second magnet 1241 is inclined relative to the axis of the first magnet 1231.

[0131] The axis a1 of the first magnet 1231 is inclined relative to the axis a2 of the second magnet 1241, and the axis a1 of the first magnet 1231 and the axis a2 of the second magnet 1241 form an angle greater than 0°. For example, the angle formed between the axis a1 of the first magnet 1231 and the axis a2 of the second magnet 1241 can be 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90°, etc. Referring to Figure 12, in some embodiments, the second speaker 1240 can be arranged on the peripheral side of the first speaker 1230, in which case the angle formed between the axis a1 of the first magnet 1231 and the axis a2 of the second magnet 1241 can be 90°. For example, the bottom of the magnetic circuit assembly of the second speaker 1240 faces the sidewall of the magnetic circuit assembly of the first speaker 1230. As an example, the bottom of the magnetic circuit assembly of the second speaker 1240 can be the surface of the second magnet facing away from the second diaphragm. The sidewall of the magnetic circuit assembly of the first speaker 1230 can be the sidewall of the receiving member. As mentioned above, since the vibration direction of the first diaphragm is parallel to the axial direction of the first magnet 1231, and the vibration direction of the second diaphragm is parallel to the axial direction of the second magnet 1241, when the axis a1 of the first magnet 1231 is tilted relative to the axis a2 of the second magnet 1241, the vibration direction of the first diaphragm is also tilted relative to the vibration direction of the second diaphragm. By setting the axis of the second magnet 1241 to be tilted relative to the axis of the first magnet 1231, it is easier to set the second sound outlet of the second speaker 340 closer to the ear canal opening (for example, in the wearing method shown in Figure 13A below), thereby increasing the listening volume of the high-frequency sound output by the second speaker 340.

[0132] By tilting the axis of the second magnet 1241 relative to the axis of the first magnet 1231, the coupling effect between the second magnet 1241 and the first magnet 1231 is weakened, and the magnetic field of the first coil of the first speaker 1230 is less affected by the second magnet 1241 of the second speaker 1240.

[0133] In some embodiments, when the axis of the second magnet 1241 is tilted relative to the axis of the first magnet 1231, the orthographic projection of the second diaphragm on the plane where the surface of the first magnet 1231 faces the first diaphragm can be spaced apart from the orthographic projection of the first diaphragm. That is, in a direction perpendicular to the vibration direction of the first diaphragm (e.g., the horizontal direction shown in FIG. 12), the first diaphragm and the second diaphragm are spaced apart, and the first magnet 1231 and the second magnet 1241 are also spaced apart. Since the second speaker 1240 in FIG. 12 is only located on one side of the first speaker 1230, exhibiting asymmetry, by tilting and spacing the first magnet 1231 and the second magnet 1241, the coupling between the second magnet 1241 and the first magnet 1231 can be further reduced, making the magnetic field distribution on the first coil of the first speaker 1230 more uniform, thereby avoiding unstable vibration of the first coil caused by magnetic field instability.

[0134] In other embodiments, when the axis of the second magnet 1241 is tilted relative to the axis of the first magnet 1231, the orthographic projection of the second diaphragm can at least partially overlap with the orthographic projection of the first diaphragm, thus ensuring a smaller volume of the acoustic output device 1200. When there are higher requirements for the volume of the acoustic output device 1200, the relative positions of the first diaphragm (first magnet 1231) and the second diaphragm (second magnet 1241) can be arranged as in this embodiment.

[0135] In some embodiments, at least a portion of the frequency of the sound output by the first speaker 1230 is lower than the frequency of the sound output by the second speaker 1240. Similar to the type of the first speaker 330 and the second speaker 340 of the acoustic output device 300, the first speaker 1230 of the acoustic output device 1200 is a low-frequency speaker or a mid-low-frequency speaker, and the second speaker 1240 is a high-frequency speaker. In some embodiments, there may be no overlap between the frequency range of the first sound output by the first speaker 1230 and the frequency range of the second sound output by the second speaker 1240. For example, the minimum frequency in the frequency range of the second sound is higher than the maximum frequency in the frequency range of the first sound. In some embodiments, there may be overlap between the frequency range of the first sound output by the first speaker 1230 and the frequency range of the second sound output by the second speaker 1240. For example, the minimum frequency in the frequency range of the second sound is lower than the maximum frequency in the frequency range of the first sound, and the maximum frequency in the frequency range of the second sound is higher than the maximum frequency in the frequency range of the first sound. Further details regarding low-frequency and high-frequency speakers can be found in the preceding descriptions and will not be repeated here.

[0136] In some embodiments, the housing of the acoustic output device 1200 may have a different wearing method than the housing 310 of the acoustic output device 300, which extends into the concha cavity. Figure 13A is a schematic diagram of another wearing method of the acoustic output device according to some embodiments of this specification. Referring to Figure 13A, in the wearing state, the support structure 1220 of the acoustic output device 1200 allows the housing 1210 to be located at the antihelix of the ear, and a portion of the side of the housing 1210 abuts against the antihelix. By positioning the housing 1210 at least partially at the user's antihelix, the output effect of the acoustic output device 1200 can be improved, i.e., increasing the sound intensity at the near-field listening position while reducing the volume of far-field sound leakage. When the user wears the acoustic output device 1200, one or more sound outlet holes may be provided on the side of the housing 1210 near or facing the user's ear canal, and one or more pressure relief holes may be provided on other sidewalls of the housing 1210 (e.g., sidewalls away from or opposite to the user's ear canal). For example, when the housing 1210 has one sound outlet, the first speaker 1230 and the second speaker 1240 share the sound outlet. As another example, when the housing 1210 has two sound outlets, one is used to output high-frequency sounds, and the other is used to output low-frequency or mid-low-frequency sounds. As yet another example, when the housing 1210 has two or more sound outlets, some are used to output high-frequency sounds, and others are used to output low-frequency or mid-low-frequency sounds. Taking a housing 1210 including one sound outlet and a pressure relief hole as an example, the sound outlet is acoustically coupled to the front cavity of the acoustic output device 1200, and the pressure relief hole is acoustically coupled to the rear cavity of the acoustic output device 1200. The sound output from the sound outlet and the sound output from the pressure relief hole can be approximated as two sound sources, with equal volume and opposite phase. The sound emitted from the sound outlet can be transmitted directly to the user's ear canal without obstruction, while the sound emitted from the pressure relief hole needs to bypass or pass through the housing 1210 to form an acoustic model similar to that shown in Figure 13B. As shown in Figure 13B, when a baffle is provided between point sound sources A1 and A2, in the near field, the sound field of point sound source A2 needs to bypass the baffle to interfere with the sound wave of point sound source A1 at the listening position, which is equivalent to increasing the sound path from point sound source A2 to the listening position. Therefore, assuming that point sound sources A1 and A2 have the same amplitude, compared with the case without a baffle, the amplitude difference of the sound waves of point sound sources A1 and A2 at the listening position increases, thereby reducing the degree of cancellation between the two sound paths at the listening position and increasing the volume at the listening position. In the far field, since the sound waves generated by point sources A1 and A2 can interfere without bypassing the baffle over a large spatial range (similar to the case without a baffle), the sound leakage in the far field will not increase significantly compared to the case without a baffle.Therefore, by setting up a baffle structure around one of the point sound sources A1 and A2, the volume at the near-field listening position can be significantly increased without significantly increasing the volume of far-field sound leakage.

[0137] Furthermore, since the housing 1210 does not block the ear canal opening and the sound volume is relatively high when worn in the manner shown in Figure 13A, the overall size of the acoustic output device 1200 can be reduced by decreasing the size between the two speakers. This allows the acoustic output device 1200 to have a higher sound quality while also improving wearing comfort. This is because, compared to the stacking arrangement of the two speakers in the acoustic output device 300, the arrangement of the two speakers in the acoustic output device 1200 can reduce the size of the acoustic output device 1200 in the vibration direction of the first diaphragm (also known as the thickness of the acoustic output device 1200). Combined with the wearing method shown in Figure 13A, the reduction in the thickness of the acoustic output device 1200 can make its center of gravity more biased towards the antihelix, preventing the acoustic output device 1200 from deflecting due to gravity, thereby increasing wearing stability and ensuring sound quality.

[0138] In the wearing method shown in Figure 13A, the housing 1210 of the acoustic output device 1200 is located at the antihelix. At this time, the inner side of the housing 1210 faces the user's ear, and the lower side of the housing 1210 is the side of the housing 1210 that faces away from the top of the user's head. Compared with the other sides of the housing 1210, the lower side of the housing 1210 is closer to the ear canal opening.

[0139] In some embodiments, the lower side of the housing 1210 of the acoustic output device 1200 may have a first sound outlet and a second sound outlet. The first sound outlet is acoustically coupled to the first diaphragm, and the sound generated by the first diaphragm is radiated outward through the first sound outlet; the second sound outlet is acoustically coupled to the second diaphragm, and the sound generated by the second diaphragm is radiated outward through the second sound outlet. When the housing 1210 of the acoustic output device 1200 is worn in contact with the antihelix, and both the first and second sound outlets are located on the lower side of the housing 1210, the first and second sound outlets can be closer to the ear canal opening, which in particular reduces the propagation distance of the sound output by the second speaker, thereby improving the listening effect of the acoustic output device 1200.

[0140] In some embodiments, when worn, the second sound outlet can be closer to the ear canal opening than the first sound outlet; that is, the sound outlet corresponding to the high-frequency speaker is closer to the ear canal opening. As an example only, when worn, the centroid of the second sound outlet projected onto the sagittal plane of the human body is closer to the ear canal opening than the centroid of the first sound outlet projected onto the sagittal plane of the human body. Given the strong directional nature of the high-frequency sound output by the second speaker 1240, by placing the second sound outlet closer to the ear canal opening, the listening volume of the high-frequency sound output by the second speaker 1240 can be further increased, thereby improving the sound effect of the acoustic output device 1200.

[0141] In some embodiments, the first sound outlet and the second sound outlet may be located on different sides of the housing 1210. In some embodiments, the first sound outlet is located on the inner side of the housing 1210, and the second sound outlet is located on the lower side of the housing 1210. In the wearing state shown in FIG13A, placing the second sound outlet of the second speaker 1240 on the lower side of the housing 1210 allows the second sound outlet to be closer to the ear canal opening, thereby making the sound output by the second speaker 1240 more directional, thereby further improving the sound effect of the acoustic output device 1200. Furthermore, a pressure relief hole may also be provided on the housing 1210, and the pressure relief hole is acoustically coupled to the first diaphragm. In some embodiments, the pressure relief hole may be located on the lower side or the upper side of the housing 1210. In other embodiments, the pressure relief hole may also be located on other sides of the housing 1210, which is not specifically limited in this specification.

[0142] In some embodiments, the second sound outlet can be disposed on the connecting surface of the housing. This connecting surface refers to the surface on the housing that connects the lower side and the inner side. In the wearing state shown in FIG13A, since the lower side of the housing 1210 faces away from the user's head and the inner side of the housing 1210 faces the antihelix, the connecting surface disposed between the lower side and the inner side allows the second sound outlet to be better directed towards the ear canal opening, thereby making the sound output by the second speaker 1240 more directional, thus further improving the sound effect of the acoustic output device 1200.

[0143] In some embodiments, the axis of the first magnet 1231 is perpendicular to the axis of the second magnet 1241. That is, in FIG. 12, the axis a1 of the first magnet 1231 and the axis a2 of the second magnet 1241 form a 90° angle. In this case, the vibration direction of the first diaphragm is perpendicular to the vibration direction of the second diaphragm. The first magnet 1231 and the second magnet 1241 are spaced apart along the vibration direction of the second diaphragm. In other embodiments, the second magnet 1241 and the first magnet 1231 may also be spaced apart along other directions, which have a certain angle with the axis of the first magnet 1231 (or the axis of the second magnet 1241), for example, 10°, 20°, 30°, 40°, 50°, 60°, etc. In other embodiments, the angle between the axis a2 of the second magnet 1241 and the axis a1 of the first magnet 1231 can be in the range of 10°-45°.

[0144] In some embodiments, when the axis a1 of the first magnet 1231 and the axis a2 of the second magnet 1241 are arranged at an angle, the N pole of the first magnet 1231 can face the first diaphragm, while the N pole of the second magnet 1241 faces the first magnet 1231. In some embodiments, the S pole of the first magnet 1231 faces the first diaphragm, and the S pole of the second magnet 1241 faces the first magnet 1231. Optionally, in a third magnet arrangement, the N pole of the first magnet 1231 faces the first diaphragm, and the S pole of the second magnet 1241 faces the first magnet 1231. Optionally, in a fourth magnet arrangement, the S pole of the first magnet 1231 faces the first diaphragm, and the N pole of the second magnet 1241 faces the first magnet 1231.

[0145] Figure 14 is a schematic diagram of the magnetic field distribution of the first and second loudspeakers according to some embodiments of this specification. In this case, the N pole of the first magnet 1231 faces the first diaphragm, and the N pole of the second magnet 1241 faces the first magnet 1231. Figure 15 is a schematic diagram of the magnetic field distribution of the first and second loudspeakers according to other embodiments of this specification. In this case, the N pole of the first magnet 1231 faces the first diaphragm, and the S pole of the second magnet 1241 faces the first magnet 1231. Combining Figures 14 and 15, when the magnetic field generated by the second loudspeaker 1240 couples with the magnetic field generated by the first loudspeaker 1230, according to the magnetic field line distribution of the two magnets, if the N pole of the first magnet 1231 faces the first diaphragm, compared to the S pole of the second magnet facing the first magnet 1231 (as shown in Figure 15), when the N pole of the second magnet faces the first magnet 1231 (as shown in Figure 14), the magnetic induction intensity at the second coil of the second loudspeaker 1240 is generally increased.

[0146] In some embodiments, there is a third distance between the magnetic circuit containing the first magnet 1231 and the magnetic circuit containing the second magnet 1241. The third distance is the shortest distance between the magnetic circuit containing the first magnet 1231 and the magnetic circuit containing the second magnet 1241. As an example, when the axis of the first magnet 1231 is perpendicular to the axis of the second magnet 1241, the third distance can be the shortest distance between the bottom of the magnetic circuit of the second speaker 1240 (e.g., the surface of the magnetic conductor / receiver facing away from the second diaphragm) and the sidewall of the receivable of the magnetic circuit assembly of the first speaker 1230 in the vibration direction of the second diaphragm.

[0147] In some embodiments, to ensure that the first speaker 1230 does not affect the vibration of the second diaphragm, the third distance may be greater than 1.5 mm. In some embodiments, to ensure that the size of the acoustic output device 1200 is not too large, the first distance may be less than 2.5 mm. In some embodiments, the third distance affects the coupling between the first magnetic field generated by the first speaker 1230 and the second magnetic field generated by the second speaker 1240. In some embodiments, the third distance may be 1.7 mm to 2.3 mm. In some embodiments, the third distance may be 1.9 mm to 2.1 mm.

[0148] In some embodiments, the inner cavity formed by the housing 1210 may include a first cavity and a second cavity separated from each other, with the first speaker 1230 housed in the first cavity and the second speaker 1240 housed in the second cavity. In some embodiments, a partition may be provided inside the housing 1210, dividing the inner cavity formed by the housing 1210 into a first cavity housing the first speaker 330 and a second cavity housing the second speaker 340. In this case, the first diaphragm of the first speaker 1230 divides the first cavity into a first front cavity and a first rear cavity, with the first front cavity acoustically coupled to a first sound outlet, and the sound generated by the first front cavity of the first speaker 1230 radiates outward through the first sound outlet. The second diaphragm of the second speaker 1240 divides the second cavity into a second front cavity and a second rear cavity, with the second front cavity acoustically coupled to a second sound outlet, and the sound generated by the second front cavity of the second speaker 1240 radiates outward through the second sound outlet. The first front cavity of the first speaker 1230 and the second front cavity of the second speaker 1240 are not acoustically connected (i.e., the first speaker 1230 and the second speaker 1240 do not share a sound outlet). This arrangement ensures that the sound radiated by the first speaker 1230 and the second speaker 1240 will not interfere with each other, thereby reducing mutual radiation impedance.

[0149] Similar to the arrangement of the second speaker 340 of the acoustic output device 300 including the third magnet 343, the second speaker 1240 of the acoustic output device 1200 may also include a third magnet (not shown) surrounding the second magnet 1241. For example, the third magnet may be a toroidal magnet surrounding the second magnet 1241.

[0150] In some embodiments, the third magnet may be configured to have opposite poles to the second magnet 1241. In this configuration, on the one hand, the magnetic field generated by the third magnet can increase the magnetic field strength at the second coil of the second speaker 1240; on the other hand, the third magnet can increase the magnetic field strength of the second magnet 1241 at the second coil.

[0151] Similar to the arrangement of the second speaker 340 of the acoustic output device 300 including the fourth magnet 344, the second speaker 1240 of the acoustic output device 1200 may also include a fourth magnet (not shown). The fourth magnet and the second magnet 1241 are arranged along the vibration direction of the second diaphragm, and the same magnetic poles of the fourth magnet and the second magnet 1241 are arranged opposite each other. In this arrangement, more magnetic field lines can pass perpendicularly through the second coil, increasing the magnetic induction intensity at the second coil and suppressing magnetic leakage, thereby increasing the sensitivity of the second speaker 1240.

[0152] In some embodiments, when the third magnet surrounds the second magnet 1241, the magnetic field generated by the second magnet 1241 can enhance the magnetic induction intensity at the first coil of the first speaker 1230, while the magnetic field generated by the third magnet will reduce the magnetic induction intensity at the first coil. Since the second magnet 1241 and the third magnet have opposite effects on the magnetic induction intensity at the first coil, it is necessary to set the dimensions of the second magnet 1241 and the third magnet to ensure that the combined magnetic field of the second speaker 1240 (i.e., the combined magnetic field obtained after coupling the magnetic field generated by the second magnet 1241 and the magnetic field generated by the third magnet) can enhance the magnetic induction intensity at the first coil. In this embodiment, the size of the magnet can be characterized by the area of ​​its cross-section perpendicular to its axis. In some embodiments, to increase the magnetic induction intensity at the first coil and thus increase the sound pressure level of the first speaker 1230, the ratio of the area of ​​the cross-section of the second magnet 1241 along its axis to the area of ​​the cross-section of the third magnet along its axis can be 0.1-4.

[0153] In some embodiments, to ensure the performance of the second loudspeaker 1240, the ratio of the area of ​​the cross-section of the second magnet 1241 along the direction perpendicular to the axis of the second magnet to the area of ​​the cross-section of the third magnet along the direction perpendicular to the axis of the third magnet can be 0.4-0.6. More information regarding the third and fourth magnets of the second loudspeaker 1240 can be found in the related descriptions above, such as Figures 8-10, and their related descriptions.

[0154] In some embodiments, the magnetic flux density at any position on the first coil of the first speaker 1230 is 0.44T-0.67T; and the magnetic flux density at any position on the second coil of the second speaker 1240 is 0.3T-0.6T. This allows both the first speaker 330 and the second speaker 340 to output sounds with a high sound pressure level, thereby increasing the user's listening volume. In some embodiments, to further increase the sound pressure level of the first speaker 1230 and the second speaker 1240, the magnetic flux density at any position on the first coil of the first speaker 1230 is 0.549T-0.562T; and the magnetic flux density at any position on the second coil of the second speaker 1240 is 0.453T-0.472T.

[0155] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0156] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0157] Furthermore, those skilled in the art will understand that aspects of this application can be described and illustrated through several patentable types or situations, including any new and useful combination of processes, machines, products, or substances, or any new and useful improvements thereof. Accordingly, aspects of this application can be implemented entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. All of the above hardware or software may be referred to as a “data block,” “module,” “engine,” “unit,” “component,” or “system.” Furthermore, aspects of this application may manifest as a computer product located on one or more computer-readable media, the product including computer-readable program code.

[0158] Computer storage media may contain a propagated data signal containing computer program code, for example, on baseband or as part of a carrier wave. This propagated signal may take various forms, including electromagnetic, optical, and suitable combinations thereof. Computer storage media can be any computer-readable medium other than a computer-readable storage medium, which can be connected to an instruction execution system, apparatus, or device to enable communication, propagation, or transmission of a program for use. The program code located on the computer storage medium can be propagated through any suitable medium, including radio, cable, fiber optic cable, RF, or similar media, or any combination of the above media.

[0159] The computer program code required for the operation of each part of this application can be written in any one or more programming languages, including object-oriented programming languages ​​such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB.NET, Python, etc., conventional procedural programming languages ​​such as C, Visual Basic, Fortran 2003, Perl, COBOL 2002, PHP, ABAP, dynamic programming languages ​​such as Python, Ruby, and Groovy, or other programming languages. This program code can run entirely on the user's computer, or as a standalone software package on the user's computer, or partially on the user's computer and partially on a remote computer, or entirely on a remote computer or processing device. In the latter case, the remote computer can be connected to the user's computer through any network, such as a local area network (LAN) or wide area network (WAN), or connected to an external computer (e.g., via the Internet), or in a cloud computing environment, or used as a service such as Software as a Service (SaaS).

[0160] Furthermore, unless expressly stated in the claims, the order of processing elements and sequences, the use of numbers and letters, or other names described in this application are not intended to limit the order of the processes and methods of this application. Although various examples have been discussed in the foregoing disclosure of some embodiments that are currently considered useful, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. Rather, the claims are intended to cover all modifications and equivalent combinations that conform to the substance and scope of the embodiments of this application. For example, while the system components described above can be implemented by hardware devices, they can also be implemented solely by software solutions, such as installing the described system on existing processing devices or mobile devices.

[0161] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0162] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of scope in some embodiments of this application are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0163] For each patent, patent application, patent application publication, and other material such as articles, books, specifications, publications, and documents referenced in this application, the entire contents of that patent are incorporated herein by reference. This excludes historical application documents that are inconsistent with or conflict with the content of this application, as well as documents that limit the broadest scope of the claims in this application (currently or subsequently appended to this application). It should be noted that if there are any inconsistencies or conflicts between the descriptions, definitions, and / or terminology used in the supplementary materials of this application and the content of this application, the descriptions, definitions, and / or terminology used in this application shall prevail.

[0164] Finally, it should be understood that the embodiments described in this application are merely illustrative of the principles of the embodiments of this application. Other modifications may also fall within the scope of this application. Therefore, alternative configurations of the embodiments of this application are considered as examples and not limitations, and are regarded as consistent with the teachings of this application. Accordingly, the embodiments of this application are not limited to the embodiments explicitly described and illustrated in this application.

Claims

1. An acoustic output device, characterized in that, include: A housing, wherein the housing forms an internal cavity; A support structure that places the shell on the ear without blocking the external auditory canal; A first loudspeaker is housed within the cavity; the first loudspeaker includes a first magnet and a first diaphragm, the first magnet and the first diaphragm being spaced apart along the vibration direction of the first diaphragm; A second loudspeaker is housed within the cavity; the second loudspeaker includes a second magnet and a second diaphragm, the second magnet and the second diaphragm being spaced apart along the vibration direction of the second diaphragm; The first magnet and the second magnet are arranged at intervals along the vibration direction of the first diaphragm; and the same magnetic poles of the first magnet and the second magnet are arranged opposite each other.

2. The acoustic output device as described in claim 1, characterized in that, At least a portion of the sound output by the first speaker has a frequency lower than the frequency of the sound output by the second speaker.

3. The acoustic output device as described in claim 1 or 2, characterized in that, The axis of the first magnet is parallel to and spaced apart from the axis of the second magnet.

4. The acoustic output device as described in claims 1-3, characterized in that, The inner side of the housing is provided with a first sound outlet and a second sound outlet. The first sound outlet is acoustically coupled to the first diaphragm, and the second sound outlet is acoustically coupled to the second diaphragm. The inner side is the side of the housing facing the ear canal when worn.

5. The acoustic output device as described in claim 4, characterized in that, When worn, the centroid of the second sound outlet is projected onto the sagittal plane of the human body closer to the ear canal opening than the centroid of the first sound outlet is projected onto the sagittal plane of the human body.

6. The acoustic output device as described in claim 4, characterized in that, When worn, the orthographic projection of the center of the second magnet onto the sagittal plane of the human body is closer to the ear canal opening than the orthographic projection of the center of the first magnet onto the sagittal plane of the human body.

7. The acoustic output device as described in any one of claims 3-6, characterized in that, On the plane where the surface of the first magnet faces the first diaphragm, the orthographic projection of the second magnet at least partially overlaps with the orthographic projection of the first magnet.

8. The acoustic output device as described in any one of claims 3-6, characterized in that, When worn, the shell extends at least partially into the concha of the ear, and at least a portion of the side of the shell abuts against the concha.

9. The acoustic output device as described in any one of claims 3-8, characterized in that, The first diaphragm includes a main body region and a folded ring region surrounding the main body region. The main body region includes an arched dome. The projection of the center of the second magnet along the axial direction of the second magnet onto the first diaphragm is located between the center of the dome and the inner edge of the folded ring. The inner edge of the folded ring is connected to the dome.

10. The acoustic output device as described in any one of claims 1-9, characterized in that, The inner cavity includes a first cavity and a second cavity separated from each other, the first speaker is housed in the first cavity, and the second speaker is housed in the second cavity.

11. The acoustic output device as described in any one of claims 3-10, characterized in that, The first distance between the magnetic circuit containing the first magnet and the magnetic circuit containing the second magnet along the vibration direction of the first diaphragm is 2.85mm-3.42mm.

12. The acoustic output device as claimed in claim 11, characterized in that, The first distance between the magnetic circuit containing the first magnet and the magnetic circuit containing the second magnet along the vibration direction of the first diaphragm is 3mm-3.2mm.

13. The acoustic output device as described in any one of claims 3-12, characterized in that, On the plane where the surface of the first magnet faces the first diaphragm, the distance between the orthographic projection of the centroid of the first diaphragm and the orthographic projection of the centroid of the second diaphragm is 0mm-8mm.

14. The acoustic output device as described in any one of claims 1-13, characterized in that, The second speaker also includes a third magnet, which is arranged around the second magnet.

15. The acoustic output device as claimed in claim 14, characterized in that, The second loudspeaker also includes a fourth magnet, which is arranged along the vibration direction of the second diaphragm with the second magnet, and the same magnetic poles of the fourth magnet and the second magnet are arranged opposite each other.

16. The acoustic output device as claimed in claim 14 or 15, characterized in that, The ratio of the area of ​​the cross section of the second magnet along the direction perpendicular to the axis of the second magnet to the area of ​​the cross section of the third magnet along the direction perpendicular to the axis of the third magnet is 0.1-4.

17. The acoustic output device as claimed in claim 16, characterized in that, The ratio of the area of ​​the cross section of the second magnet along the direction perpendicular to the axis of the second magnet to the area of ​​the cross section of the third magnet along the direction perpendicular to the axis of the third magnet is 0.4-0.

6.

18. The acoustic output device as claimed in any one of claims 1-17, characterized in that, The first loudspeaker includes a first coil connected to the first diaphragm and at least partially located in the magnetic field formed by the first magnet. When the first coil is energized, it drives the first diaphragm to vibrate to produce sound. The magnetic flux density at any point on the first coil is greater than 0.45T; and / or, The second loudspeaker includes a second coil connected to the second diaphragm and at least partially located in the magnetic field formed by the second magnet. When the second coil is energized, it drives the second diaphragm to vibrate to produce sound. The magnetic flux density at any point on the second coil is greater than 0.3T.

19. An acoustic output device, characterized in that, include: A housing, wherein the housing forms an internal cavity; A support structure that places the shell on the ear without blocking the external auditory canal; A first loudspeaker is housed within the cavity; the first loudspeaker includes a first magnet and a first diaphragm, the first magnet and the first diaphragm being spaced apart along the vibration direction of the first diaphragm; A second loudspeaker is housed within the cavity; the second loudspeaker includes a second magnet and a second diaphragm, the second magnet and the second diaphragm being spaced apart along the vibration direction of the second diaphragm; wherein the axis of the second magnet is inclined relative to the axis of the first magnet.

20. The acoustic output device as claimed in claim 19, characterized in that, On the plane where the surface of the first magnet faces the first diaphragm, there is a gap between the orthographic projection of the second diaphragm and the orthographic projection of the first diaphragm.

21. The acoustic output device as claimed in claim 19, characterized in that, At least a portion of the sound output by the first speaker has a frequency lower than the frequency of the sound output by the second speaker.

22. The acoustic output device as described in any one of claims 19-21, characterized in that, The lower side of the housing is provided with a first sound outlet and a second sound outlet. The first sound outlet is acoustically coupled to the first diaphragm, and the second sound outlet is acoustically coupled to the second diaphragm. The lower side is the side of the housing that faces away from the user's head when worn.

23. The acoustic output device as described in any one of claims 19-21, characterized in that, The inner side of the housing has a first sound outlet, and the lower side of the housing has a second sound outlet. The first sound outlet is acoustically coupled to the first diaphragm, and the second sound outlet is acoustically coupled to the second diaphragm. The inner side is the side of the housing facing the antihelix when worn, and the lower side is the side of the housing away from the top of the user's head when worn.

24. The acoustic output device as described in any one of claims 19-23, characterized in that, The axis of the first magnet is perpendicular to the axis of the second magnet, and the first magnet and the second magnet are spaced apart along the vibration direction of the second diaphragm.

25. The acoustic output device as described in any one of claims 19-23, characterized in that, The angle between the axis of the first magnet and the axis of the second magnet is 10°-45°.

26. The acoustic output device as claimed in claim 24, characterized in that, The third distance between the magnetic circuit containing the first magnet and the magnetic circuit containing the second magnet is 1.5mm-2.5mm.

27. The acoustic output device as described in any one of claims 19-26, characterized in that, When worn, the support structure positions the housing at the antihelix of the ear, and a portion of the side of the housing abuts against the antihelix.

28. The acoustic output device as described in any one of claims 19-27, characterized in that, The inner cavity includes a first cavity and a second cavity separated from each other, the first speaker is housed in the first cavity, and the second speaker is housed in the second cavity.

29. The acoustic output device as described in any one of claims 19-28, characterized in that, The second speaker also includes a third magnet arranged around the second magnet.

30. The acoustic output device as claimed in claim 29, characterized in that, The second speaker also includes a fourth magnet, the second magnet and the fourth magnet being arranged along the vibration direction of the second diaphragm; and the same magnetic poles of the second magnet and the fourth magnet being arranged opposite each other.

31. The acoustic output device as claimed in claim 29 or 30, characterized in that, The ratio of the area of ​​the cross section of the second magnet along the direction perpendicular to the axis of the second magnet to the area of ​​the cross section of the third magnet along the direction perpendicular to the axis of the third magnet is 0.1-4.

32. The acoustic output device as claimed in claim 31, characterized in that, The ratio of the area of ​​the cross section of the second magnet along the direction perpendicular to the axis of the second magnet to the area of ​​the cross section of the third magnet along the direction perpendicular to the axis of the third magnet is 0.4-0.

6.

33. The acoustic output device as described in any one of claims 19-32, characterized in that, The first loudspeaker includes a first coil connected to the first diaphragm and at least partially located in the magnetic field formed by the first magnet. When the first coil is energized, it drives the first diaphragm to vibrate to produce sound. The magnetic induction intensity at any position on the first coil is 0.44T-0.67T; and / or, The second loudspeaker includes a second coil connected to the second diaphragm and at least partially located in the magnetic field formed by the second magnet. When the second coil is energized, it drives the second diaphragm to vibrate to produce sound. The magnetic induction intensity at any position on the second coil is 0.3T-0.6T.

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