Loudspeaker

Abstract

The embodiment of the specification provides a loudspeaker. The loudspeaker comprises a vibrating diaphragm and a shell. The diaphragm may vibrate to generate an air-guided acoustic wave. The shell can form a containing cavity used for containing the vibrating diaphragm, the vibrating diaphragm divides the containing cavity to form a front cavity and a rear cavity, the shell is provided with a sound outlet hole communicated with the front cavity, at least part of air guide sound waves are transmitted to the outside of the loudspeaker through the sound outlet hole, the shell is provided with a sound absorption pipeline, and the sound absorption pipeline is communicated with the front cavity. The sound absorption pipeline is communicated with at least one of the front cavity and the rear cavity, the sound absorption pipeline is used for absorbing sound waves of a target frequency in the air-guided sound waves, and the length of the sound absorption pipeline is within the range of 3 / 20-2 / 5 of the wavelength of the sound waves of the target frequency.

Description

speaker Technical Field

[0001] The present invention relates to the field of acoustic devices, and in particular to a loudspeaker with a sound-absorbing pipe provided on its shell. Background Art

[0002] With the continuous development of electronic devices, speakers (e.g., headphones) have become indispensable social and entertainment tools in people's daily lives, and people's requirements for speakers are becoming increasingly higher. However, existing speakers still have many problems, such as complex structures and poor sound quality. Therefore, it is desirable to provide a speaker with a simple structure and high acoustic performance to meet user needs.

[0003] Summary of the Invention

[0004] One of the embodiments of the present specification provides a loudspeaker, comprising: a diaphragm, which vibrates to generate air-conducted sound waves; and a shell, the shell forming a housing cavity for accommodating the diaphragm, the diaphragm dividing the housing cavity to form a front cavity and a rear cavity, the shell being provided with a sound outlet hole connected to the front cavity, at least part of the air-conducted sound waves being transmitted to the outside of the loudspeaker through the sound outlet hole, wherein the shell is provided with a sound absorption pipe, the sound absorption pipe being connected to at least one cavity in the front cavity and the rear cavity, the sound absorption pipe being used to absorb sound waves of a target frequency in the air-conducted sound waves, wherein the length of the sound absorption pipe is in the range of 3 / 20-2 / 5 of the wavelength of the sound waves of the target frequency.

[0005] In some embodiments, in some embodiments, the vibration of the diaphragm has an original resonant frequency, and the difference between the original resonant frequency and the target frequency is within 300 Hz.

[0006] In some embodiments, the target frequency is in the range of 3 kHz-20 kHz.

[0007] In some embodiments, the front cavity is connected to the sound outlet hole through a sound guiding channel, and the sound absorbing pipe is connected to the sound guiding channel through the front cavity.

[0008] In some embodiments, the shell includes a front cavity plate, a rear cavity plate, and a side plate, and one end of the sound absorbing duct includes a sound inlet.

[0009] In some embodiments, the speaker also includes a driving unit, which is used to generate vibration based on an electrical signal and drive the diaphragm to vibrate, wherein the driving unit is arranged in the rear cavity, and the driving unit cooperates with the rear cavity plate to divide the rear cavity into a first rear cavity and a second rear cavity, wherein the second rear cavity is composed of the driving unit and the rear cavity plate.

[0010] In some embodiments, the sound absorbing pipe is disposed in the rear cavity plate and communicates with the first rear cavity through the sound inlet.

[0011] In some embodiments, the sound absorbing pipe is disposed in the front cavity plate and communicates with the front cavity through the sound inlet.

[0012] In some embodiments, the other end of the sound-absorbing pipe is closed.

[0013] In some embodiments, the sound inlet is located within a projection of the diaphragm along its vibration direction.

[0014] In some embodiments, the diaphragm includes a folding ring portion and a fixed end, and the sound inlet faces the folding ring portion.

[0015] In some embodiments, a projection of the sound absorbing pipe along the vibration direction of the diaphragm includes a meandering structure or a folded structure.

[0016] In some embodiments, the speaker further includes a driving unit, and the meandering structure is arranged around the driving unit on a projection plane along the vibration direction of the driving unit.

[0017] In some embodiments, the sound absorbing duct includes one or more sub-sound absorbing ducts, and the one or more sub-sound absorbing ducts are connected to the front cavity or the rear cavity through a sound inlet respectively.

[0018] In some embodiments, the plurality of sub-sound absorbing pipes are symmetrically distributed along the central axis of the speaker.

[0019] In some embodiments, at least two of the plurality of sub-sound absorbing ducts absorb sound waves of the same or different frequencies in the air-conducted sound waves.

[0020] In some embodiments, the equivalent length of the sound absorbing pipe is in the range of 4 mm to 28 mm.

[0021] In some embodiments, the equivalent diameter of the sound absorbing pipe is not less than 0.05 mm.

[0022] In some embodiments, the front cavity is connected to the sound outlet through a sound guiding channel, and the sound absorbing pipe is arranged on the side wall of the sound guiding channel and is connected to the sound guiding channel through a sound inlet provided at one end.

[0023] In some embodiments, the sound absorbing duct comprises a 1 / 4 wavelength resonance tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] This specification will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0025] FIG1 is a block diagram of an exemplary speaker according to some embodiments of the present specification;

[0026] FIG2 is a schematic structural diagram of an exemplary sound-absorbing duct according to some embodiments of this specification;

[0027] FIG3 is a schematic structural diagram of an exemplary speaker according to some embodiments of this specification;

[0028] FIG4 is a frequency response curve of an exemplary speaker according to some embodiments of the present specification;

[0029] FIG5 is a frequency response curve of an exemplary speaker according to some other embodiments of this specification;

[0030] FIG6A is a schematic diagram of a three-dimensional structure of an exemplary sound-absorbing duct according to some embodiments of this specification;

[0031] FIG6B is a schematic diagram of an AA cross-section of the sound-absorbing pipe in FIG6A according to some embodiments of the present specification;

[0032] FIG6C is a schematic diagram of an AA cross-section of the sound-absorbing pipe in FIG6A according to other embodiments of the present specification;

[0033] FIG7A is a schematic diagram of a three-dimensional structure of an exemplary sound-absorbing duct according to some embodiments of this specification;

[0034] FIG7B is a schematic diagram of a cross-section taken along line BB of the sound-absorbing pipe in FIG7A according to some embodiments of the present specification;

[0035] FIG7C is a schematic diagram of a BB cross-section of the sound-absorbing pipe in FIG7A according to other embodiments of this specification;

[0036] FIG7D is a schematic diagram of a BB cross-section of the sound-absorbing pipe in FIG7A according to other embodiments of this specification;

[0037] FIG7E is a schematic diagram of a BB cross-section of the sound-absorbing pipe in FIG7A according to other embodiments of this specification;

[0038] FIG8A is a schematic structural diagram of an exemplary speaker according to some embodiments of this specification;

[0039] FIG8B is a schematic diagram of an AA cross-section of the sound-absorbing pipe in FIG8A according to some embodiments of the present specification;

[0040] FIG9A is a schematic structural diagram of an exemplary speaker according to other embodiments of this specification;

[0041] FIG9B is a schematic diagram of an AA cross-section of the sound absorbing pipe in FIG9A according to some embodiments of the present specification;

[0042] FIG10A is a schematic structural diagram of an exemplary speaker according to other embodiments of this specification;

[0043] FIG10B is a schematic diagram of an AA cross-section of the sound absorbing pipe in FIG10A according to some embodiments of the present specification;

[0044] FIG11A is a schematic structural diagram of an exemplary speaker according to other embodiments of this specification;

[0045] FIG11B is a schematic diagram of an AA cross-section of the sound absorbing pipe in FIG11A according to some embodiments of the present specification;

[0046] FIG12 is a schematic structural diagram of an exemplary speaker according to some embodiments of the present specification. DETAILED DESCRIPTION

[0047] To more clearly illustrate the technical solutions of the embodiments of this application, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0048] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, other terms may be used to replace a term if they achieve the same purpose.

[0049] As used in this application and the claims, unless the context clearly indicates an exception, the words "a", "an", "an kind" and / or "the" do not specifically refer to the singular and may also include the plural, unless the context clearly indicates an exception. Generally speaking, the terms "including" and "comprising" only indicate the inclusion of the steps and elements that have been explicitly identified, and these steps and elements do not constitute an exclusive list. The method or apparatus may also include other steps or elements. The term "based on" means "at least in part based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment".

[0050] 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 understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include at least one of such features. In the description of this specification, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0051] In this specification, unless otherwise specified or limited, terms such as "connected" and "fixed" should be interpreted broadly. For example, the term "connected" can refer to a fixed connection, a removable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; and can refer to internal communication between two components or an interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this specification based on the specific circumstances.

[0052] The loudspeaker provided in the embodiments of this specification may include a diaphragm, a housing, and a sound-absorbing duct. The diaphragm can vibrate to generate air-conducted sound waves. The housing can form a housing for accommodating the diaphragm. The diaphragm divides the housing into a front cavity and a rear cavity. The housing is provided with a sound outlet hole connected to the front cavity, and at least a portion of the air-conducted sound waves is transmitted to the exterior of the loudspeaker through the sound outlet hole. The housing is provided with a sound-absorbing duct. The sound-absorbing duct is connected to at least one of the front and rear cavities and is configured to absorb sound waves of a target frequency in the air-conducted sound waves. In some embodiments, by providing a sound-absorbing duct on the housing, the sound-absorbing duct is connected to at least one of the front and rear cavities and is configured to absorb sound waves of a target frequency in the air-conducted sound waves, thereby making the frequency response curve of the loudspeaker flatter and improving the acoustic performance of the loudspeaker. In addition, the provision of the sound-absorbing duct can influence the vibration state of the diaphragm in the loudspeaker, thereby adjusting the frequency response curve of the loudspeaker and achieving the effect of built-in structural filtering of the loudspeaker.

[0053] The speaker provided in the embodiments of this specification is described in detail below with reference to the accompanying drawings.

[0054] FIG1 is a block diagram of an exemplary loudspeaker according to some embodiments of the present disclosure. As shown in FIG1 , the loudspeaker 100 may include a diaphragm 110 , a housing 120 , and a sound absorbing duct 130 .

[0055] The diaphragm 110 can vibrate to generate air-conducted sound waves. In some embodiments, the diaphragm 110 can directly receive an electrical signal and convert the electrical signal into a vibration signal. For example, the diaphragm 110 may include a piezoelectric diaphragm, an electrostatic driving diaphragm, etc. In other words, in some embodiments, the diaphragm 110 is also a driving unit. In some embodiments, the speaker 100 may include a driving unit (for example, the driving unit 170 in Figure 3). The driving unit can receive an electrical signal and convert the electrical signal into a vibration signal. The driving unit can transmit the vibration signal to the diaphragm 110, for example, through a vibration transfer unit, thereby driving the diaphragm 110 to vibrate. In some embodiments, the driving unit may include a moving coil driving unit, a moving iron driving unit, an electrostatic driving unit, a piezoelectric driving unit, etc. For ease of description, this application will be described in a manner where the diaphragm and the driving unit are independently arranged, which does not limit the scope of this application.

[0056] The housing 120 may form a housing for accommodating other components of the speaker 100 (e.g., the diaphragm 110, the driver, etc.). The diaphragm 110 may separate the housing into a front cavity and a rear cavity. The housing 120 may be provided with a sound outlet hole communicating with the front cavity. At least a portion of the air-conducted sound waves generated by the vibration of the diaphragm 110 may be transmitted to the exterior of the speaker 100 through the sound outlet hole.

[0057] The housing 120 may be provided with a sound-absorbing duct 130. The duct communicates with at least one of the front and rear cavities and is configured to absorb airborne sound waves of a target frequency. In other words, the duct 130 may have a sound-absorbing function. For more information on the duct 130, please refer to other sections of this application (e.g., Figures 2-5, 6A-12, and their descriptions).

[0058] Figure 2 is a schematic diagram of the structure of an exemplary sound-absorbing duct according to some embodiments of this specification. As shown in Figure 2 , the sound-absorbing duct 130 may include a sound wave reflecting surface 134 and a sound absorption duct inlet 132. An incident sound wave 220 emitted by a sound source 210 may enter the sound absorption duct 130 through the sound absorption duct inlet 132 and propagate within the sound absorption duct 130 along the positive x-axis. Furthermore, upon reaching the sound wave reflecting surface 134, the incident sound wave 220 is reflected, forming a reflected sound wave 230. The reflected sound wave 230 is reflected in a direction opposite to the incident direction of the incident sound wave 220.

[0059] 2 , the position of the sound wave reflecting surface 134 is defined as the origin O of the x-axis, and the sound pressure P of the incident sound wave 220 is i and the sound pressure P of the reflected sound wave 230 r They can be expressed as:

[0060] P i =P ai ej(ωt-kx) (1)

[0061] P r =P ar e j(ωt+kx) (2)

[0062] Among them, P ai is the sound pressure amplitude of the incident sound wave 220, P ar is the sound pressure amplitude of the reflected sound wave 230, ω is the vibration circular frequency, t is time, k is the wave number, and x is the coordinate of the sound wave on the x-axis.

[0063] Combining equations (1) and (2), the total sound pressure P in the sound absorbing duct 130 can be expressed as:

[0064]

[0065] in, is the introduced phase, |P| is the total sound pressure amplitude of the incident sound wave 220 and the reflected sound wave 230, and |P| can be expressed as:

[0066]

[0067] Among them, r p is the sound pressure reflection coefficient, σπ is the phase difference between the reflected sound wave 230 and the incident sound wave 220 at the sound wave reflecting surface 134 , and λ is the wavelength of the sound wave.

[0068] According to equation (4), when When the total sound pressure amplitude |P| reaches the minimum value, That is, the distance between the sound absorbing pipe 130 and the sound wave reflecting surface 134 is In some embodiments, the sound wave reflecting surface 134 may be a rigid reflecting surface that can fully reflect the incident sound wave 220. Accordingly, the sound pressure reflection coefficient r p =1,σ=0, at this time That is, the distance between the sound absorbing pipe 130 and the sound wave reflecting surface 134 is The minimum value of the total sound pressure amplitude can be obtained at the position of When the sound pressure amplitude at the sound inlet 132 of the sound absorbing pipe reaches a minimum value, the sound absorbing pipe 130 can absorb the sound waves of the target frequency (ie, wavelength λ). In some embodiments, the sound absorbing pipe 130 can include a 1 / 4 wavelength resonance pipe.

[0069] FIG3 is a schematic structural diagram of an exemplary speaker according to some embodiments of this specification.

[0070] As shown in FIG3 , the speaker 100 may include a diaphragm 110, a housing 120, a sound-absorbing duct 130, a front cavity 140, a rear cavity 150, a vibration transmission unit 160, and a driver unit 170. The housing 120 may form a housing for accommodating one or more components of the speaker 100 (e.g., the diaphragm 110, the driver unit 170, etc.). The diaphragm 110 may include a folding ring 111 and a fixed end 112. The diaphragm 110 is connected to the housing 120 via the fixed end 112 and separates the housing cavity to form the front cavity 140 and the rear cavity 150. The driver unit 170 may perform energy conversion, converting electrical energy (i.e., an electrical signal) into mechanical energy (i.e., a vibration signal), and transmit the generated mechanical energy to the diaphragm 110 via the vibration transmission unit 160. Driven by the driver unit 170, the diaphragm 110 may vibrate and push air to generate air-conducted sound waves. At least a portion of the air-conducted sound waves may be transmitted to the outside of the speaker 100 through a sound outlet (not shown).

[0071] In some embodiments, the housing 120 may include a front cavity plate 122, a rear cavity plate 124, and a side plate 126. The front cavity plate 122, the rear cavity plate 124, and the side plate 126 collectively form the aforementioned accommodating cavity. In some embodiments, the front cavity plate 122, the rear cavity plate 124, and / or the side plate 126 may include a printed circuit board (PCB), a plastic plate, a metal plate, etc., which is not limited in this application.

[0072] In some embodiments, the drive unit 170 can be disposed in the rear cavity 150. In some embodiments, the rear cavity 150 can be divided or undivided by setting the placement of the drive unit 170. For example, for a piezoelectric speaker, the drive unit 170 can be fixed to the speaker housing 120 (e.g., the rear cavity plate 124) via a bracket with holes, thereby not dividing the rear cavity 150. For another example, for an electromagnetic speaker, its magnetic circuit portion (i.e., the drive unit 170) can be fixed to the housing 120 (e.g., the rear cavity plate 124) via a bracket with holes, thereby not dividing the rear cavity 150. For another example, as shown in Figure 3, the drive unit 170 can be fixed to the rear cavity plate 124 and cooperate with the rear cavity plate 124 to divide the rear cavity 150 into a first rear cavity 152 and a second rear cavity 154. The first rear cavity 152 can be surrounded by at least a portion of the housing 120, at least a portion of the diaphragm 110, the drive unit 170, and the vibration transmission unit 160. The second rear cavity 154 can be enclosed by the drive unit 170 and the rear cavity plate 124. The second rear cavity 154 can be connected to the exterior of the speaker 100 or not. For ease of description, this application will use the arrangement in which the drive unit 170 can divide the rear cavity 150 as an example, which does not limit the scope of this application.

[0073] One end of the sound absorption duct 130 may include a sound inlet 132, and the other end may be closed to form a sound wave reflecting surface 134. In some embodiments, the sound absorption duct 130 may be disposed on the front cavity panel 122, the rear cavity panel 124, the side panel 126, or the like. For example, as shown in FIG3 , the sound absorption duct 130 may be disposed on the rear cavity panel 124 and communicate with the first rear cavity 152 via the sound inlet 132. In some embodiments, the sound absorption duct 130 may be used to absorb sound waves of a target frequency within the air-conducted sound waves generated by the diaphragm 110, thereby adjusting the frequency response curve of the loudspeaker 100. For example, the sound absorption duct 130 may absorb sound waves of a target frequency within the air-conducted sound waves, thereby reducing the sound wave component of the target frequency contained in the sound waves output from the loudspeaker 100. Accordingly, the sound pressure of the sound waves output from the loudspeaker 100 near the target frequency decreases, which is reflected as a trough in the frequency response curve (trough A in curve 420 shown in FIG4 ), thereby adjusting the frequency response curve of the loudspeaker 100.

[0074] In some embodiments, the frequency response curve of the speaker 100 can be adjusted by adjusting one or more parameters (e.g., shape, position, size, etc.) of the sound absorbing pipe 130. For example, in conjunction with FIG. 2 and its description, when the equivalent length of the sound absorbing pipe is When the sound pressure amplitude of a sound wave with a target frequency and a wavelength of λ is minimized at the sound inlet 132, the sound absorption duct 130 can absorb the sound wave at the target frequency, thereby creating a trough in the frequency response curve of the speaker 100 near the target frequency. Therefore, the target frequency (e.g., the location of the trough) of the sound wave absorbed by the sound absorption duct 130 can be adjusted by adjusting the equivalent length l of the sound absorption duct, thereby achieving troughs in different frequency bands on the frequency response curve of the speaker 100, enabling the speaker 100 to meet actual needs and enhance the user experience. In some embodiments, the equivalent length l of the sound absorption duct 130 can be approximately 1 / 4 of the wavelength λ of the sound wave at the target frequency. For example, the equivalent length l of the sound absorption duct 130 can be within a range of 1 / 10 to 2 / 5 of the wavelength λ of the sound wave at the target frequency. For another example, the equivalent length l of the sound absorption duct 130 can be within a range of 3 / 20 to 2 / 5 of the wavelength λ of the sound wave at the target frequency. For another example, the equivalent length l of the sound absorption duct 130 can be in the range of 1 / 5 to 3 / 10 of the wavelength λ of the sound wave at the target frequency. In some embodiments, the size of the equivalent diameter d of the sound absorption duct 130 affects the acoustic impedance of the sound absorption duct 130, thereby affecting the valley formed on the frequency response curve of the speaker 100. For example, a value of d that is too small will result in a large acoustic impedance, making the sound absorption duct 130 ineffective in achieving sound absorption. In some embodiments, to ensure that the sound absorption duct 130 has sound absorption effectiveness, the equivalent diameter d of the sound absorption duct 130 can be no less than 0.05 mm. For example, the equivalent diameter d of the sound absorption duct 130 can be no less than 0.3 mm. For another example, the equivalent diameter d of the sound absorption duct 130 can be no less than 0.1 mm. For more information about the sound absorption duct 130, please refer to Figures 6A-12 of this specification and their descriptions, and will not be repeated here.

[0075] FIG. 4 is a frequency response curve of an exemplary loudspeaker according to some embodiments of the present specification.

[0076] As shown in Figure 4, curve 410 represents the frequency response curve of a speaker without a sound absorbing duct, and curve 420 represents the frequency response curve of a speaker with a sound absorbing duct (such as speaker 100).

[0077] As can be seen from FIG4 , for a loudspeaker without a sound-absorbing duct, the vibration of its diaphragm can have a corresponding resonant frequency (the frequency corresponding to the resonant peak B of the frequency response curve 410 ). Due to the existence of the resonant frequency of the diaphragm vibration, the frequency response curve of the loudspeaker without a sound-absorbing duct is not flat enough. A sound-absorbing duct (e.g., the sound-absorbing duct 130 ) can be set on the loudspeaker housing (e.g., the front cavity plate 122 , the rear cavity plate 124 , etc. of the housing 120 ). Due to the sound-absorbing effect of the sound-absorbing duct on the target frequency sound waves, the response of the loudspeaker's frequency response curve at the target frequency position can be reduced. As shown in FIG3 , setting the sound-absorbing frequency of the sound-absorbing duct (i.e., the target frequency) at the resonant frequency of the diaphragm vibration can effectively suppress the peak value of the diaphragm vibration at this frequency, and can even cause the overall frequency response curve of the loudspeaker to have a trough at the resonant frequency of the diaphragm vibration.

[0078] By way of example only, for a loudspeaker with a sound-absorbing duct, the vibration of its diaphragm may have a corresponding original resonant frequency (which can be approximately the frequency corresponding to resonance peak B in frequency response curve 410). In some embodiments, by designing the parameters of the sound-absorbing duct (e.g., shape, position, dimensions, etc.), the target frequency corresponding to the sound-absorbing duct can be positioned near the original resonant frequency of the diaphragm vibration. This significantly reduces the peak value of the loudspeaker with the sound-absorbing duct at the original resonant frequency, forming a trough with two peaks appearing on either side of the trough (e.g., peaks C and D in FIG4 , where the amplitudes corresponding to peaks C and D are both smaller than resonance peak B, and the amplitude difference between peak C or peak D and resonance peak B may be greater than 6 dB, and the amplitude difference between valley A and resonance peak B may be greater than 12 dB). This improves the overall sensitivity of the loudspeaker and flattens the loudspeaker's frequency response curve. In some embodiments, the difference between the target frequency and the original resonant frequency may be within 300 Hz. In some embodiments, the difference between the target frequency and the original resonant frequency may be within 200 Hz. In some embodiments, the difference between the target frequency and the original resonant frequency may be within 100 Hz. In some embodiments, the target frequency may be equal to the original resonant frequency.

[0079] In some embodiments, a speaker's frequency response curve is typically relatively smooth in the low- and mid-frequency ranges, while the mid- and high-frequency ranges are affected by the higher-order modes of the speaker diaphragm and driver, as well as the modes of the sound absorption duct, resulting in more resonance peaks. Therefore, to smooth the speaker's frequency response curve in these ranges, the sound absorption duct can be designed so that its target frequency falls within these ranges. In some embodiments, the target frequency can be in the range of 1 kHz to 20 kHz. Accordingly, the equivalent length of the sound absorption duct can be in the range of 4 mm to 80 mm. In some embodiments, the target frequency can be in the range of 3 kHz to 20 kHz. Accordingly, the equivalent length of the sound absorption duct can be in the range of 4 mm to 28 mm. In some embodiments, the target frequency can be in the range of 3 kHz to 10 kHz. Accordingly, the equivalent length of the sound absorption duct can be in the range of 8 mm to 28 mm. In some embodiments, the target frequency can be in the range of 3 kHz to 8 kHz. Accordingly, the equivalent length of the sound absorption duct can be in the range of 10 mm to 28 mm. In some embodiments, the target frequency can be in the range of 1.2 kHz to 8 kHz. Accordingly, the equivalent length of the sound absorbing duct may be in the range of 10 mm to 70 mm.

[0080] As shown in Figure 4, the frequency response curve of a speaker with a sound-absorbing duct is flatter than that of a speaker without a sound-absorbing duct, resulting in a better acoustic effect. In some embodiments, the depth of the trough can be adjusted by adjusting the damping of one or more components of the speaker (e.g., sound-absorbing duct 130), thereby making the frequency response curve of the speaker even flatter and further improving the acoustic effect of the speaker.

[0081] FIG5 is a frequency response curve of an exemplary speaker according to other embodiments of the present specification. As shown in FIG5 , curve 510 represents the frequency response curve of a speaker without a sound absorption duct. Curve 520 represents the frequency response curve of a speaker with an equivalent length l of a sound absorption duct of 17 mm. Curve 530 represents the frequency response curve of a speaker with an equivalent length l of a sound absorption duct of 7 mm. As can be seen from FIG5 , by providing a sound absorption duct (corresponding to curve 520 or 530) on the speaker housing, a trough can be formed at a specific frequency (for example, a frequency range between 5 kHz and 12 kHz), and two peaks can be formed on the left and right sides of the trough, thereby improving the sensitivity of the speaker. Furthermore, by adjusting the equivalent length l of the sound absorption duct, the trough (or target frequency) can be placed at different positions to achieve a sound absorption effect on sound waves of different target frequencies.

[0082] Figure 6A is a schematic diagram of a three-dimensional structure of an exemplary sound-absorbing duct according to some embodiments of the present specification. Figures 6B-6C are schematic diagrams of the AA cross-section of the sound-absorbing duct in Figure 6A.

[0083] In some embodiments, as shown in FIG6A , the sound absorption duct 130 may include a sound absorption cavity 136 and a sound inlet 132. The dimensions (e.g., equivalent length l of the sound absorption duct 130 , equivalent diameter d of the sound absorption duct 130 ), shape, etc. of the sound absorption duct 130 may be designed to absorb sound waves of different target frequencies, thereby forming valleys at different locations on the frequency response curve of the speaker 100.

[0084] In some embodiments, the shape of the sound absorption duct (or cross-section AA) along the vibration direction of the diaphragm can include a meander or folded structure. As shown in Figure 6B , the shape of the sound absorption duct 130 along cross-section AA can be a meander. In some embodiments, the loudspeaker further includes a drive unit, and the meander can be disposed around the drive unit in the projection plane along the vibration direction of the drive unit. For example, the sound absorption duct 130 can be disposed on the side panel 126, with its shape along cross-section AA being a meander that surrounds the drive unit. For another example, the sound absorption duct 130 can also be disposed on the front cavity panel 122 or the rear cavity panel 124, with its shape along cross-section AA being a meander. For a detailed description of the positional relationship between the drive unit and the meander, please refer to Figures 8A and 8B and the related descriptions. As shown in Figure 6C , the shape of the sound absorption duct 130 along cross-section AA can also be a folded structure. It is understood that, without violating the principles of the embodiments of this specification, the shape of the sound absorption duct 130 along cross-section AA can also be W-shaped, S-shaped, or irregular, and this specification does not limit this.

[0085] In some embodiments, the more turns the meandering structure wraps around the driver unit, or the more times the folded structure folds, the longer the equivalent length of the sound-absorbing duct. This increases the wavelength λ corresponding to the target frequency, and the lower the frequency of sound waves that the sound-absorbing duct can absorb. By designing the meandering and / or folded structures, a sufficiently long sound-absorbing duct can be provided within a limited space (i.e., within the structures of the front cavity panel 122, rear cavity panel 124, and side panels 126), allowing the duct to absorb sound waves at lower target frequencies, thereby increasing the practicality of the speaker while miniaturizing the speaker.

[0086] Figure 7A is a schematic diagram of a three-dimensional structure of an exemplary sound-absorbing duct according to some embodiments of the present specification. Figures 7B-7E are schematic diagrams of the BB cross-section of the sound-absorbing duct in Figure 7A.

[0087] In some embodiments, as shown in FIG7A , the sound absorption duct 130 may include a sound absorption cavity 136 and a sound inlet 132. The dimensions (e.g., length l of the sound absorption duct 130 , minor diameter d of the sound absorption duct 130 ), shape, etc. of the sound absorption duct 130 may be designed to absorb sound waves of different target frequencies, thereby forming valleys at different locations on the frequency response curve of the speaker 100.

[0088] The cross-sections shown in Figures 7B-7D may be obtained when the cross-section at AA of the sound-absorbing duct 130 is in a zigzag or folded configuration. In some embodiments, the cross-section at BB of the sound-absorbing duct 130 may include a plurality of rectangles, circles, and triangles arranged side by side. It is understood that the cross-section at BB of the sound-absorbing duct 130 may also be an ellipse, polygon, or irregular shape, without departing from the principles of the embodiments of this specification, and this specification does not limit this.

[0089] In some embodiments, the sound-absorbing ducts can be arranged in layers along the vibration direction of the diaphragm. As shown in Figure 7E , the shape of the sound-absorbing duct 130 in the BB cross-section can be multiple rectangular layers. By arranging these sound-absorbing ducts in layers, the length of the ducts can be further increased, further enhancing the practicality of the speaker while maintaining its compact size.

[0090] Fig. 8A is a schematic diagram of the structure of an exemplary loudspeaker according to some embodiments of the present specification. Fig. 8B is a schematic diagram of the AA cross section of the sound absorbing pipe in Fig. 8A.

[0091] In some embodiments, as shown in FIG8A , the sound absorption duct 130 can be disposed in the rear cavity plate 124 and communicate with the first rear cavity 152 through the sound inlet 132. In some embodiments, the sound inlet 132 can be located within the projection of the diaphragm 110 along its vibration direction. The sound absorption duct 130 can reduce the sound pressure amplitude of the air-conducted sound waves generated by the diaphragm 110 at the sound inlet 132, and can thereby affect the air near the diaphragm 110 through the sound inlet 132. Therefore, the position of the sound inlet 132 can be set to affect the local air in different parts of the diaphragm 110, thereby changing the state of the diaphragm 110 and making the vibration of the diaphragm more in line with the use requirements of the speaker.

[0092] In some embodiments, the diaphragm 110 may include a folding portion 111 and a fixed end 112. In some embodiments, the sound inlet 132 may be provided at a position close to the folding portion 111 of the diaphragm 110. For example, the sound inlet 132 may be directly opposite the folding portion 111 of the diaphragm 110. For example, on a projection plane along the vibration direction of the diaphragm 110, the center of the sound inlet 132 may coincide with the center of the folding portion 111. Generally speaking, the closer the portion of the diaphragm 110 is to the folding portion 111, the smaller its stiffness is, and the closer the portion is to the fixed end 112, the greater its stiffness is. Therefore, the closer the sound inlet 132 is to the edge of the fixed end 112, the smaller its effect on the diaphragm 110; the closer the sound inlet 132 is to the middle of the folding portion 111, the greater its effect on the diaphragm 110. By positioning the sound inlet 132 near the fold 111, the sound absorption duct 130 can affect the local air near the fold 111, thereby more easily affecting the vibration state of the diaphragm 110, thereby facilitating adjustment of the acoustic performance of the speaker 100. In some embodiments, when it is desired that the sound absorption duct 130 have a smaller impact on the vibration of the diaphragm 110, the sound inlet 132 can be positioned near the fixed end 112 of the diaphragm 110. By positioning the sound inlet 132 near the fixed end 112, the sound absorption duct 130 can have a smaller impact on the local air near the fold 111, thereby reducing the impact of the sound absorption duct 130 on the vibration state of the diaphragm 110 and enabling fine-tuning of the acoustic performance of the speaker 100.

[0093] In some embodiments, as shown in FIG8B , the structure of the sound absorption duct 130 may include a meandering structure. On a projection plane along the vibration direction of the driver unit 170 (or diaphragm 110 ), the meandering structure of the sound absorption duct 130 surrounds the driver unit 170 . This allows for a longer sound absorption duct to be installed within the limited space of the rear cavity panel 124 . This allows the sound absorption duct 130 to absorb sound waves at lower target frequencies, thereby increasing the practicality of the speaker 100 while miniaturizing the speaker 100 .

[0094] Fig. 9A is a schematic diagram of the structure of an exemplary loudspeaker according to some other embodiments of the present specification. Fig. 9B is a schematic diagram of the AA cross section of the sound absorbing pipe in Fig. 9A.

[0095] In some embodiments, the sound absorption duct 130 may include one or more sub-sound absorption ducts, each of which may be connected to the front cavity 140 or the rear cavity 150 via a sound inlet. For example, as shown in Figures 9A and 9B, the sound absorption duct 130 may include a sub-sound absorption duct 130-1 and a sub-sound absorption duct 130-2. Sub-sound absorption ducts 130-1 and 130-2 each connect to the first rear cavity 152 via a sound inlet. In some embodiments, at least two of the multiple sub-sound absorption ducts can absorb sound waves of different frequencies in the air-conducted sound wave. For example, when sound waves of multiple target frequencies need to be absorbed, the lengths l of sub-sound absorption duct 130-1 and sub-sound absorption duct 130-2 can be set to different values. This allows the two sub-sound absorption ducts to absorb sound waves of different frequencies, thereby increasing the sound absorption bandwidth of the sound absorption duct 130, flattening the frequency response curve of the speaker 100, and improving the sound quality of the speaker. In some embodiments, at least two of the multiple sub-sound absorbing ducts can absorb sound waves of the same frequency in the air-conducted sound waves. For example, the lengths l of sub-sound absorbing duct 130-1 and sub-sound absorbing duct 130-2 can be set to the same value so that the two sub-sound absorbing ducts can absorb sound waves of the same frequency at different locations. This can adjust the vibration state of diaphragm 110 at different locations, thereby improving the sound absorption effect of sound absorbing duct 130.

[0096] In some embodiments, if multiple sub-sound absorption ducts are arranged at localized locations on the rear cavity panel 124, the sound absorption duct 130 may locally affect the motion of the diaphragm 110, causing an imbalance in the air stiffness within the rear cavity 150 (e.g., the first rear cavity 152), thereby tilting the diaphragm 110 and causing high-order modal resonance peaks on the frequency response curve of the loudspeaker 100, thereby reducing the acoustic output of the loudspeaker. Therefore, to prevent unnecessary high-order modes in the loudspeaker 100, the multiple sub-sound absorption ducts may be symmetrically (or nearly symmetrically) distributed along the central axis of the loudspeaker 100. For example, the positions of the multiple sub-sound absorption ducts (e.g., the positions of the sound inlets) may be symmetrically (or nearly symmetrically) distributed along the central axis of the loudspeaker 100. For another example, the shapes of the multiple sub-sound absorption ducts may be symmetrically (or nearly symmetrically) distributed along the central axis of the loudspeaker 100. Furthermore, by arranging the multiple sub-sound absorption ducts symmetrically about the central axis of the loudspeaker 100, the structure of the rear cavity panel 124 (or front cavity panel 122) may be more reliable, thereby extending the life of the loudspeaker. For example, as shown in FIG9A , the speaker 100 may include a sub-sound absorption duct 130-1 and a sub-sound absorption duct 130-2, and the two sub-sound absorption ducts may be located on either side of the central axis of the speaker 100. Furthermore, the two sub-sound absorption ducts may be symmetrically arranged in the rear cavity panel 124 around the central axis of the speaker 100, and each communicate with the first rear cavity 152 through a sound inlet.

[0097] Fig. 10A is a schematic diagram of the structure of an exemplary loudspeaker according to some other embodiments of the present specification. Fig. 10B is a schematic diagram of the AA cross section of the sound absorbing pipe in Fig. 10A.

[0098] In some embodiments, as shown in FIG10A , the sound absorption duct 130 is disposed in the front cavity plate 122 and is connected to the front cavity 140 through the sound inlet 132. The sound waves generated by the diaphragm 110 can enter the sound absorption cavity of the sound absorption duct 130 through the sound inlet 132. In some embodiments, the sound inlet 132 can be located within the projection of the diaphragm 110 along its vibration direction. For example, the sound inlet 132 can be disposed directly opposite the folding ring portion 111 of the diaphragm 110. In some embodiments, as shown in FIG10A and FIG10B , the sound absorption duct 130 disposed at the front cavity plate 122 can include one or more sub-sound absorption ducts. For a detailed description of the sub-sound absorption ducts, please refer to FIG9A , FIG9B and the related descriptions, which will not be repeated here.

[0099] In some embodiments, by designing the sound absorption duct 130 in the front cavity plate 122, the sound absorption duct 130 can not only affect the vibration state of the speaker 100, but also directly absorb part of the air-conducted sound waves generated by the vibration of the diaphragm 110, thereby affecting the acoustic performance of the speaker 100. In this specification, direct absorption can mean that since the sound absorption duct 130 is connected to the front cavity 140, the sound absorption duct 130 can absorb the sound waves of the target frequency during the process of the air-conducted sound waves being transmitted to the sound outlet. Compared with the rear cavity plate 124, by designing the sound absorption duct 130 at the front cavity plate 122, the sound absorption effect is more obvious, which can directly affect the acoustic performance of the speaker 100, and its design is simpler and more convenient, which is convenient for subsequent assembly. In some embodiments, the front cavity 140 can be connected to the sound outlet through a sound guide channel (not shown). The sound absorption duct 130 can be connected to the sound guide channel through the front cavity 140. In other words, the sound absorbing duct 130 designed in the front cavity plate 122 can be directly connected to the front cavity 140, and indirectly connected to the sound outlet through the front cavity 140 and the sound guide channel.

[0100] Fig. 11A is a schematic diagram of the structure of an exemplary loudspeaker according to some other embodiments of the present specification. Fig. 11B is a schematic diagram of the AA cross section of the sound absorbing pipe in Fig. 11A.

[0101] In some embodiments, the speaker shown in FIG11A can be similar to the speaker shown in FIG9A , except that the other end of the sound-absorbing duct 130 in the speaker 100 shown in FIG11A can further include a sound-absorbing structure 138. In some embodiments, the sound-absorbing structure comprises at least one of a porous sound-absorbing material or a damping mesh. In some embodiments, the sound-absorbing structure 138 can change the phase difference σπ between the incident sound wave and the reflected sound wave at the sound wave reflection surface (i.e., the end of the sound-absorbing duct 130), thereby adjusting the required length of the sound-absorbing duct for the same target frequency. For example, the porous sound-absorbing material can increase the equivalent constant of the sound-absorbing duct, and the damping mesh can be used to adjust the damping of the sound-absorbing duct 130, thereby reducing the required length of the sound-absorbing duct for the same target frequency. Furthermore, the sound-absorbing structure 138 can also reduce the quality factor (i.e., Q value) of the speaker 100, thereby reducing the depth of the valley created by the sound-absorbing duct 130 and making the frequency response curve of the speaker 100 flatter.

[0102] In this embodiment, by providing a sound-absorbing structure 138 at the end of the sound-absorbing duct 130, the length of the sound-absorbing duct 130 is no longer the sole factor in determining the corresponding target frequency. For speakers with small size and narrow space where it is inconvenient to provide a longer sound-absorbing duct, a sound-absorbing structure can be provided at the end of the sound-absorbing duct to replace the longer sound-absorbing duct, thereby improving the output effect of the speaker.

[0103] FIG12 is a schematic structural diagram of an exemplary speaker according to some embodiments of the present specification.

[0104] In some embodiments, as shown in FIG12 , the front cavity 140 of the speaker housing 120 can be connected to the sound outlet 190 through a sound guide channel 180. The sound absorption duct 130 can be disposed in the sound guide channel 180, that is, the sound absorption duct 130 can be connected to the front cavity 140 through the sound guide channel 180. In other words, the sound absorption duct 130 is connected to the sound outlet 190 only through the sound guide channel. By designing the sound absorption duct 130 in the side wall of the sound guide channel 180, the design is simpler and more convenient, and also facilitates subsequent assembly. For example, different sound guide channels equipped with different sound absorption ducts can be used as accessories, and components other than the sound guide channels equipped with sound absorption ducts can be used as basic components. Different accessories can be assembled on the same basic component to achieve different adjustments to the frequency response of the speaker, so that the speaker can adapt to different application scenarios.

[0105] The beneficial effects that may be brought about by the embodiments of this application include but are not limited to: (1) by arranging a sound-absorbing pipe on the speaker housing, a trough is generated on the speaker frequency response curve, so that the speaker directly emits the sound after the adjusted frequency response, thereby achieving the effect of the speaker's own structural filtering; (2) by adjusting the shape, position, size, etc. of the sound-absorbing pipe, the target frequency corresponding to the sound-absorbing pipe is made the same or close to the original resonant frequency of the diaphragm, thereby making the speaker frequency response curve flatter, thereby improving the acoustic performance of the speaker; (3) by designing a meandering structure, a folding structure, etc., the sound-absorbing pipe can absorb sound waves of lower target frequencies, thereby increasing the practicality of the speaker while ensuring the miniaturization of the speaker volume; (4) by arranging the sound-absorbing pipe in the front cavity plate and / or the rear cavity plate, and combining it with a damping net, sound-absorbing material, etc., the speaker frequency response curve is further flattened, thereby further improving the acoustic performance of the speaker; (5) by arranging multiple sub-sound-absorbing pipes to be symmetrically (or approximately symmetrically) distributed with respect to the central axis of the speaker, the reliability of the speaker housing is improved, space is saved, and the processing cost of the speaker is reduced. It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects that may be produced may be any one or a combination of the above, or any other possible beneficial effects.

[0106] The basic concepts have been described above. It will be apparent to those skilled in the art that the detailed disclosure above is merely illustrative and does not limit the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and amendments to the present application. Such modifications, improvements, and amendments are suggested in the present application and remain within the spirit and scope of the exemplary embodiments of the present application.

Claims

1. A loudspeaker, comprising: a diaphragm that vibrates to generate air-conducted sound waves; as well as A housing is formed to accommodate the diaphragm, the diaphragm divides the housing to form a front cavity and a rear cavity, and the housing is provided with a sound outlet hole communicating with the front cavity, and at least part of the air-conducted sound waves are transmitted to the outside of the speaker through the sound outlet hole, wherein: A sound-absorbing pipe is provided on the shell, and the sound-absorbing pipe is connected to at least one cavity of the front cavity and the rear cavity. The sound-absorbing pipe is used to absorb sound waves of a target frequency in the air-conducted sound waves, wherein the length of the sound-absorbing pipe is between 3 / 20 and 2 / 5 of the wavelength of the sound waves of the target frequency.

2. The loudspeaker according to claim 1, wherein The vibration of the diaphragm has an original resonant frequency, and the difference between the original resonant frequency and the target frequency is within 300 Hz.

3. The loudspeaker according to claim 1 or 2, wherein: The target frequency is in the range of 3kHz-20kHz.

4. The loudspeaker according to any one of claims 1 to 3, wherein The front cavity is communicated with the sound outlet through a sound guide channel, and the sound absorbing pipe is communicated with the sound guide channel through the front cavity.

5. The loudspeaker according to any one of claims 1 to 4, wherein The shell includes a front cavity plate, a rear cavity plate and a side plate, and one end of the sound absorbing pipe includes a sound inlet.

6. The loudspeaker according to claim 5, wherein The speaker also includes a driving unit, which is used to generate vibration based on an electrical signal and drive the diaphragm to vibrate, wherein the driving unit is arranged in the rear cavity, and the driving unit cooperates with the rear cavity plate to divide the rear cavity into a first rear cavity and a second rear cavity, wherein the second rear cavity is composed of the driving unit and the rear cavity plate.

7. The loudspeaker according to claim 6, wherein The sound absorbing pipe is arranged in the rear cavity plate and communicates with the first rear cavity through the sound inlet.

8. The loudspeaker according to claim 5, wherein The sound absorbing pipe is arranged in the front cavity plate and communicates with the front cavity through the sound inlet.

9. The loudspeaker according to any one of claims 5 to 8, wherein The other end of the sound-absorbing pipe is sealed.

10. The loudspeaker according to any one of claims 6 to 9, wherein The sound inlet is located within the projection of the diaphragm along its vibration direction.

11. The loudspeaker according to any one of claims 6 to 10, wherein: The diaphragm includes a folding ring portion and a fixed end, and the sound inlet is opposite to the folding ring portion.

12. The loudspeaker according to claim 1, wherein The projection of the sound-absorbing pipe along the vibration direction of the diaphragm includes a meandering structure or a folded structure.

13. The loudspeaker according to claim 12, wherein The loudspeaker further includes a driving unit, and the meandering structure is arranged around the driving unit on a projection plane along the vibration direction of the driving unit.

14. The loudspeaker according to any one of claims 1 to 13, wherein The sound absorbing pipe includes one or more sub-sound absorbing pipes, and the one or more sub-sound absorbing pipes are respectively connected to the front cavity or the rear cavity through a sound inlet.

15. The loudspeaker according to claim 14, wherein The plurality of sub-sound absorbing pipes are symmetrically distributed along the central axis of the loudspeaker.

16. The loudspeaker according to claim 14 or 15, wherein At least two of the plurality of sub-sound absorbing pipes absorb sound waves of the same or different frequencies in the air-conducted sound waves.

17. The loudspeaker according to any one of claims 1 to 16, wherein The equivalent length of the sound-absorbing pipe is in the range of 4 mm to 28 mm.

18. The loudspeaker according to any one of claims 1 to 17, wherein The equivalent diameter of the sound-absorbing pipe is not less than 0.05 mm.

19. The loudspeaker according to claim 1, wherein The front cavity is communicated with the sound outlet through a sound guide channel, and the sound absorbing pipe is arranged on a side wall of the sound guide channel and is communicated with the sound guide channel through a sound inlet provided at one end.

20. The loudspeaker according to any one of claims 1 to 19, wherein The sound-absorbing pipe includes a 1 / 4 wavelength resonance tube.

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