Loudspeaker

Abstract

The embodiment of the invention provides a loudspeaker. The loudspeaker comprises a magnetic circuit assembly; at least part of the coil assembly is located in the magnetic gap formed by the magnetic circuit assembly, and the coil assembly drives the vibration piece to vibrate to generate sound after being powered on. The coil assembly comprises a coil support, the coil support is provided with an extension end extending towards the magnetic gap, and the extension end is provided with a first step structure; the coil comprises an outer side coil and an inner side coil, a second step structure is formed by the outer side coil and the inner side coil in the direction close to the coil support, and the first step structure and the second step structure are in butt joint so that the coil can be fixedly installed on the coil support.

Description

speaker Technical Field

[0001] The present invention relates to the field of electrical equipment, and in particular to a loudspeaker. Background Art

[0002] Existing speakers often use a method of bonding the coil bracket to the coil. The bonding area between the coil bracket and the coil is not large enough, resulting in poor reliability of the speaker. The coil is easily misaligned or falls off the coil bracket under frequent vibration. In addition, the space utilization rate of the coil bracket and the coil is not high, and the sensitivity needs to be improved.

[0003] Therefore, it is hoped to provide a loudspeaker with higher sensitivity and better reliability from the perspective of optimizing the configuration and materials of the coil bracket and the coil.

[0004] Summary of the Invention

[0005] One embodiment of this specification provides a speaker, comprising: a magnetic circuit assembly; a coil assembly, at least partially located in a magnetic gap formed by the magnetic circuit assembly, wherein the coil assembly drives a vibrating member to vibrate to produce sound when energized. The coil assembly comprises: a coil bracket, the coil bracket having an extended end extending toward the magnetic gap, the extended end having a first step structure; and a coil, the coil comprising an outer coil and an inner coil, wherein the outer coil and the inner coil form a second step structure in a direction approaching the coil bracket, the first step structure and the second step structure being in contact with each other, so that the coil is fixedly mounted to the coil bracket.

[0006] In some embodiments, along the extension direction of the coil support, the height of the inner coil is greater than the height of the outer coil.

[0007] In some embodiments, along the extension direction of the coil support, the height of the inner coil is smaller than the height of the outer coil.

[0008] In some embodiments, the inner coil and the outer coil have the same width in the radial direction.

[0009] In some embodiments, the width of the outer coil in the radial direction is wider than the width of the inner coil in the radial direction.

[0010] In some embodiments, the coil is a metal wire having an elongation of not less than 20%.

[0011] In some embodiments, the coil includes a conductor, an insulation layer, and a glue layer from inside to outside in the radial direction of the coil, and the total thickness of the insulation layer and the glue layer in the radial direction is not less than 0.016 mm.

[0012] In some embodiments, the step parameter H1 and height position parameter H2 of the coil satisfy the following conditions: H1+0.5mm≤H2≤1.8mm, wherein the step parameter H1 is 1 / 2 of the height difference between the inner coil and the outer coil along the extension direction of the coil bracket, the height position parameter H2 is the distance between the reference plane and the top of the coil bracket away from the docking direction, and the reference plane is the plane where 1 / 2 of the height difference between the inner coil and the outer coil along the extension direction of the coil bracket is located.

[0013] In some embodiments, the step parameter H1 is in the range of 0.1 mm to 0.8 mm.

[0014] In some embodiments, the height position parameter H2 is in the range of 1.1 mm to 1.6 mm.

[0015] In some embodiments, the distance between the lower step surface of the coil support and the top of the coil support in the direction away from the docking is not less than 0.5 mm.

[0016] In some embodiments, the magnetic circuit assembly includes a first magnet and a magnetic conductive cover at least partially surrounding the first magnet. Along the extension direction of the coil bracket, the distance between the bottom of the coil and the bottom surface of the magnetic conductive cover is not less than 0.9 mm.

[0017] In some embodiments, a gap between the coil and the first magnet in a radial direction is in a range of 0.25 mm to 0.35 mm.

[0018] In some embodiments, the magnetic circuit assembly further includes a second magnet and a magnetic conductive plate, the magnetic conductive plate is located between the first magnet and the second magnet, and the magnetic properties of the first magnet and the second magnet are opposite.

[0019] Another embodiment of this specification provides a speaker, comprising: a magnetic circuit assembly; a coil assembly, at least partially located within a magnetic gap formed by the magnetic circuit assembly, wherein the coil assembly, when energized, drives a vibrating member to vibrate to produce sound. The coil assembly comprises: a coil support having an extended end extending toward the magnetic gap; and a coil, the coil comprising an outer coil and an inner coil, the outer coil and the inner coil forming a stepped structure in a direction approaching the coil support, and the coil being a metal wire having an elongation of not less than 20%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present application 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:

[0021] FIG1 is an exemplary module diagram of a speaker according to some embodiments of the present specification;

[0022] FIG2 is an exemplary structural diagram of a speaker according to some embodiments of this specification;

[0023] FIG3 is an exemplary structural diagram of another speaker according to some embodiments of this specification;

[0024] FIG4 is an exemplary structural diagram of another speaker according to some embodiments of this specification;

[0025] FIG5 is an exemplary structural diagram of another speaker according to some embodiments of this specification;

[0026] FIG6 is a curve showing the relationship between the coil driving force factor BL and the height position parameter H2 under different step parameters H1 according to some embodiments of this specification;

[0027] FIG7 is a radial cross-sectional view of a coil according to some embodiments of the present specification; and

[0028] FIG. 8 is a schematic diagram of coil arrangement according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0029] 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.

[0030] An embodiment of the present specification provides a loudspeaker comprising a magnetic circuit assembly and a coil assembly, wherein the coil assembly is at least partially located within a magnetic gap formed by the magnetic circuit assembly. When energized, the coil assembly drives a vibrating element to vibrate, thereby generating sound. The coil assembly comprises a coil support having an extended end extending toward the magnetic gap, the extended end having a first step structure. The coil assembly further comprises a coil, comprising an outer coil and an inner coil. Approaching the coil support, the outer coil and the inner coil form a second step structure, the first step structure and the second step structure being in contact with each other, with each step of the first step structure facing a step of the second step structure, such that the coil is securely mounted to the coil support. In the present specification, by providing a step structure between the extended end of the coil support and the coil, the bonding area between the coil support and the coil is increased, further improving the strength and reliability of the bonding. Alternatively or additionally, the coil is constructed of a high-tension wire with a self-melting layer (e.g., a copper alloy wire with an elongation of not less than 20%), which ensures bonding strength within the coil and between the coil and the coil support, further improving bonding reliability.

[0031] When the coil is energized in a magnetic field, the Lorentz force on each charge at the microscopic level is calculated by formula (1):

[0032] F q =quB (1)

[0033] Among them, F q is the Lorentz force; q is the charge; u is the charge velocity; and B is the magnetic flux density at that point. Assuming that the charge distribution in the current-carrying straight wire is uniform and the charge velocity is the same, the current in the current-carrying straight wire is calculated by formula (2):

[0034] I=nqSu (2)

[0035] Where I is the current in the straight wire; n is the number of charges per unit volume; and S is the cross-sectional area of ​​the wire. The macroscopic Ampere force generated by the straight wire after it is energized is calculated using the following formula (3):

[0036] F=nwSLuB=BIL (3)

[0037] Where F is the macroscopic Ampere force and L is the length of the straight wire. For a uniform multi-turn energized coil, the total microscopic Lorentz force it experiences is calculated using the following formula (4):

[0038] Among them, S0 is the cross-sectional area of ​​a single wire; B r is the radial magnetic flux density modulus at each point of the coil. Assume the cross-sectional area of ​​the coil is A and the number of turns is N0, then The coil driving force factor BL is calculated by formula (5):

[0039] For a coil of a specific shape, the number of turns and the cross-sectional area of ​​the coil are constant. Therefore, in the simulation calculation, it is only necessary to calculate B in the coil area. r Performing the volume integral and dividing it by the cross-sectional area of ​​a single coil conductor, S0, yields the coil driving force factor, BL. This factor reflects the coil's sensitivity; a larger BL reflects the coil's sensitivity.

[0040] FIG. 1 is an exemplary module diagram of a speaker according to some embodiments of the present specification.

[0041] As shown in FIG. 1 , the speaker 100 may include a magnetic circuit assembly 110 and a coil assembly 120 .

[0042] The magnetic circuit assembly 110 can be used to generate a magnetic field in space and position the coil assembly 120 at least partially within the magnetic field. In some embodiments, the magnetic circuit assembly 110 can be composed of permanent magnets and other components with magnetic conductivity. For example, the magnetic circuit assembly 110 can include a magnet, a magnetic shield, and a magnetic plate. For a detailed description of the magnetic circuit assembly 110, see Figures 2, 3, 4, and 5 and the related descriptions. In some embodiments, a magnetic gap may be formed in the magnetic circuit assembly 110.

[0043] Coil assembly 120 can be used to generate vibration. Coil assembly 120 is at least partially located within the magnetic gap formed by magnetic circuit assembly 110. When energized, coil assembly 120 drives the vibrating element to vibrate, generating sound. For example, when energized, coil assembly 120 generates an Ampere force under the influence of an external magnetic field (such as the magnetic field generated by magnetic circuit assembly 110). The direction of the Ampere force is determined by the left-hand rule. Coil assembly 120 may include a coil support 121 and a coil 122.

[0044] The coil support 121 can be used to support the coil 122. The coil support 121 has an extended end extending toward the magnetic gap, and the extended end has a first step structure. In some embodiments, the coil support 121 can be shaped like a ring, a hollow cylinder, a hollow elliptical cylinder, etc. The space in the center of the coil support 121 can be used to accommodate at least a portion of the magnetic circuit assembly 110. For example, the space in the center of the coil support 121 can accommodate a magnet, a magnetic conductive plate, etc.

[0045] Coil 122 can generate an Ampere force under the influence of the current and the external magnetic field, and produce damping during vibration. Coil 122 can include an outer coil 122-1 and an inner coil 122-2. Approaching the coil support 121, outer coil 122-1 and inner coil 122-2 form a second step structure. The first step structure and the second step structure are in contact with each other, so that coil 122 is fixed to coil support 121. It should be understood that the description of two step structures in contact with each other in this specification refers to each step of one step structure being opposite to a step of the other step structure, and the two opposite step surfaces are in contact with each other. For example, each step of the first step structure is opposite to a step of the second step structure, and the two opposite step surfaces are in contact with each other. For a detailed description of the first and second step structures, see Figures 2, 3, 4, and 5 and the related descriptions. In some embodiments, the conductor of coil 122 can be enameled wire. For example, copper wire or aluminum wire with an insulation layer can be used. For a structural description of coil 122, see Figure 7 and the related descriptions. In some embodiments, the coil 122 may be wrapped around the coil support 121. For a detailed description of the wrapping method, see FIG8 and its related description.

[0046] FIG. 2 is an exemplary structural diagram of a speaker according to some embodiments of the present specification.

[0047] As shown in FIG2 , the speaker 100 may include a magnetic circuit assembly 110, a coil assembly 120, and a vibration transmission plate 214. Specifically, the magnetic circuit assembly 110 may include a magnetic conductive cover 211 and a first magnet 212. The coil assembly 120 may include a coil support 121 and a coil 122. Specifically, the coil 122 may further include an outer coil 122-1 and an inner coil 122-2. The extension direction shown in FIG2 refers to the docking direction between the coil support 121 and the coil 122, and the radial direction is perpendicular to the extension direction.

[0048] The magnetic circuit assembly 110 can place the coil 122 in a stable magnetic gap. For example, the first magnet 212 in the magnetic circuit assembly 110 can generate a magnetic field that can act on the coil 122. The spatial location of the magnetic gap can include a spatial region surrounded by the magnetic shield 211 and the first magnet 212. The first magnet 212 can be a permanent magnet. For example, the first magnet 212 can include a neodymium iron boron magnet, a ferrite magnet, an alnico magnet, etc. In some embodiments, the shape of the first magnet 212 can be a cylinder, an elliptical cylinder, etc. In some embodiments, at least a portion of the first magnet 212 can be located in the ring structure surrounded by the coil assembly 120. For example, in Figure 2, there is a certain gap between the first magnet 212 and the coil support 121 and the coil 122 of the coil assembly 120. An exemplary gap can be 0.3 mm.

[0049] The magnetic cover 211 can change the magnetic field distribution and generate magnetic shielding. The magnetic cover 211 can prevent the first magnet 212 from radiating a magnetic field outward. The magnetic cover 211 can be a structure with a cavity, and its cavity can be used to accommodate other components of the magnetic circuit assembly 110 and the coil assembly 120. The magnetic cover 211 can be made of a material with a high magnetic permeability. For example, soft iron, silicon steel, Permalloy, iron-aluminum alloy, etc. The magnetic cover 211 can increase the magnetic field strength of the first magnet 212 at the coil assembly 120 and prevent the magnetic field from interfering with other external components.

[0050] The vibration transmitting piece 214 can vibrate under the drive of the coil assembly 120 and transmit the vibration to the shell of the speaker 100. Further, the vibration of the shell is transmitted to the user's auditory nerve through the bones of the user's head, etc., thereby generating sound. In some embodiments, as shown in Figure 2, at least a portion of the vibration transmitting piece 214 can be connected to the coil bracket 121. It should be understood that the direct connection between the vibration transmitting piece 214 and the magnetic circuit assembly 110 (for example, the first magnet 212 or the magnetic cover 211) shown in Figure 2 is only an example, and the vibration transmitting piece 214 can be connected to the magnetic circuit assembly 110 (for example, the first magnet 212 or the magnetic cover 211) through other connection structures, which is not limited here.

[0051] The coil 122 in the coil assembly 120 vibrates under the action of the current and the external magnetic field, and transmits the vibration to the vibration transmitting piece 214. The coil support 121 can be used to support the coil 122. In some embodiments, the coil support 121 has an extension end extending toward the magnetic gap, and the extension end has a first step structure. The extension end of the coil support 121 in Figure 2 can extend in a vertically downward direction (i.e., a downward extension direction). The first step structure can be a stepped structure in the coil support 121 that contacts the coil 122. As shown in Figure 2, taking the first step structure including two steps as an example, assuming that the AA section (the section at 1 / 2 of the height difference between the inner coil 122-2 and the outer coil 122-1 along the extension direction of the coil support 121) is used as the reference plane, the first step structure may include a raised portion and a recessed portion. The raised portion may be a step that passes vertically downward through the AA section (i.e., the portion of the coil support 121 close to the outer coil 122-1 shown in Figure 2), and the recessed portion may be a step that does not reach the AA section (i.e., the portion of the coil support 121 close to the inner coil 122-2 shown in Figure 2). The raised portion and the recessed portion of the first step structure are connected by a transition side surface parallel to the extension direction. In some embodiments, the raised portion of the first step structure contacts the outer coil 122-1 of the coil 122, the recessed portion of the first step structure contacts the inner coil 122-2 of the coil 122, and the transition side surface between the raised portion and the recessed portion of the first step structure contacts the inner coil 122-2 of the coil 122. In some embodiments, coil support 121 can be shaped like a ring, a hollow cylinder, or a hollow elliptical cylinder. The space in the center of coil support 121 can be used to accommodate magnetic circuit assembly 110. For example, the space in the center of coil support 121 can be used to accommodate a magnet, a magnetic conductive plate, etc. In some embodiments, coil support 121 can be made of kraft paper, asbestos paper, polyimide, aluminum foil, copper foil, fiberglass, etc.

[0052] The coil 122 may include an outer coil 122-1 and an inner coil 122-2. In the radial direction shown in FIG2 , the inner coil 122-2 is located on the inner side of the coil 122 and close to the first magnet 212, while the outer coil 122-1 is located on the outer side of the coil 122 and away from the first magnet 212. In the direction close to the coil support 121 (i.e., the upward extension direction in FIG2 ), the outer coil 122-1 and the inner coil 122-2 form a second step structure. The first step structure and the second step structure are connected to each other, so that the coil 122 is fixedly mounted on the coil support 121. The second step structure may be a stepped structure in the coil 122 that contacts the coil support 121. In some embodiments, along the extension direction of the coil support 121, the height of the inner coil 122-2 is greater than the height of the outer coil 122-1. Taking the example of a second step structure comprising two steps, assuming that the AA section (the section at 1 / 2 of the height difference between the inner coil 122-2 and the outer coil 122-1 along the extension direction of the coil support 121) is used as the reference plane, the second step structure may also include a raised portion and a recessed portion. The raised portion of the second step structure may be a step that passes vertically upward through the AA section (i.e., the portion of the inner coil 122-2 close to the coil support 121 in FIG. 2 ). In some embodiments, the raised portion of the second step structure contacts the recessed portion of the first step structure. The recessed portion of the second step structure may be a step lower than the AA section (i.e., the portion of the outer coil 122-1 close to the coil support 121 in FIG. 2 ). The raised portion of the second step structure and the recessed portion of the second step structure are connected by a transition side surface parallel to the extension direction. In some embodiments, the recessed portion of the second step structure contacts the raised portion of the first step structure, the raised portion of the second step structure contacts the recessed portion of the first step structure, and the transition side surface of the second step structure contacts the transition side surface of the first step structure. In some embodiments, the first step structure and the second step structure may be bonded by adhesive. For example, the portion where the first step structure and the second step structure meet can be glued and fixed by an adhesive such as silicone. In this embodiment, by setting the height of the inner coil 122-2 to be greater than the height of the outer coil 122-1 and simultaneously providing the first step structure of the coil support 121, the coil 122 and the coil support 121 not only have contact areas at the raised portion and the recessed portion, respectively, but also contact each other at the transition side surfaces of the two step structures. This can increase the contact area between the coil support 121 and the coil 122, improve the firmness of the connection between the coil support 121 and the coil 122, and reduce the possibility of the coil 122 falling off the coil support 121 along the extension direction during vibration. In addition, the coil support 121 can constitute a stress constraint on the coil 122 in the radial direction, thereby preventing the coil 122 from being misaligned in the radial direction during vibration.It should be noted that the outer coil 122 - 1 and the inner coil 122 - 2 may be coils wound with the same conductive wire, and are distinguished as inner and outer due to different winding positions.

[0053] In some embodiments, the width of the inner coil 122-2 and the outer coil 122-1 in the radial direction can be the same. For example, the width of the raised portion and the recessed portion of the second step structure in Figure 2 in the radial direction are the same. At this time, when the inner coil 122-2 and the outer coil 122-1 are wound using the same wire, the number of turns of the inner coil 122-2 in the radial direction is the same as the number of turns of the outer coil 122-1 in the radial direction. Correspondingly, the width of the recessed portion and the raised portion of the first step structure can also be the same to achieve size matching with the second step structure. The inner coil 122-2 and the outer coil 122-1 have the same width in the radial direction, and the width of the recessed portion and the raised portion of the first step structure of the coil support 121 in the radial direction are also the same, which facilitates the winding of the coil 122 and the manufacture of the coil support 121.

[0054] In some embodiments, coil 122 can be made of a metal wire with an elongation of at least 20%. Exemplary metal wires can include copper alloy wires. Using wires with a certain elongation (e.g., a elongation of at least 20%) allows coil 122 to be pre-stretched during the winding process. This improves the adhesion of the wires in coil 122, stabilizes the bond between coil 122 and coil support 121, and enhances the firmness of the connection between coil support 121 and coil 122, reducing the possibility of coil 122 falling off coil support 121 along the extension direction during vibration, thereby increasing reliability. For a detailed description of the coil winding process, see Figure 8 and its related description. Furthermore, using copper alloy wire with an elongation of at least 20% can avoid tensile fracture or reduced tensile strength during pre-stretching of coil 122 due to insufficient ductility. Exemplary copper alloy wire elongations can be 20%, 30%, 40%, etc. In some embodiments, the copper alloy wire can include nickel-copper alloy wire, zirconium-copper alloy wire, etc. It should be understood that elongation refers to the ratio of the increase in the length of a metal wire to its original length. In this specification, the elongation of a metal wire can be measured according to the IEC 60851-3 standard. For example, on a tensile tester or a tensile testing machine, a metal wire with a test length of 200 mm to 250 mm is stretched at a rate of (5 ± 1) mm / s until it breaks. The ratio of the increased length after breaking to the original length is calculated. The average value of the three tests is the elongation of the metal wire.

[0055] In some embodiments, in order to avoid collision caused by a small distance between the bottom of the coil 122 and the bottom surface of the inner part of the magnetic cover 211 (for example, along the extension direction of the coil support, the distance between the bottom of the coil 122 and the bottom surface of the inner part of the magnetic cover 211 can be not less than 0.9 mm, that is, to meet the H L =4.4mm-(H2+1.7mm)≥0.9mm, where 4.4mm represents the dimension of the magnetic cover 211 of the loudspeaker 100 along the extension direction, and 1.7mm represents the distance between the reference plane AA and the lowest end of the coil support 121 close to the bottom of the magnetic cover 211). At the same time, in order to meet the processing requirements and strength requirements of the coil support 121 (for example, the distance between the lower step surface of the coil support 121 and the top of the coil support 121 in the direction away from the docking (that is, the height of the lowest step surface of the coil support 121 in the docking direction) is not less than 0.5mm, that is, to meet H H =H2-H1≥0.5mm), the loudspeaker 100 has a larger coil driving force factor BL. Based on the above two conditions, the step parameter H1 and height position parameter H2 of the coil 122 can meet the following conditions: H1+0.5mm≤H2≤1.8mm, where the step parameter H1 is 1 / 2 of the height difference between the inner coil 122-2 and the outer coil 122-1 along the extension direction of the coil support 121, and the height position parameter H2 is the distance between the reference plane AA and the top of the coil support 121 away from the docking direction. In some embodiments, the reference plane AA is the plane where 1 / 2 of the height difference between the inner coil 122-2 and the outer coil 122-1 along the extension direction of the coil support 121 is located. It should be understood that the dimension of 4.4 mm in the extension direction of the magnetic cover 211 of the speaker 100 used to limit the step parameter H1 and the height position parameter H2 of the coil 122 and the distance of 1.7 mm between the reference plane AA and the lowest end of the coil bracket 121 near the bottom of the magnetic cover 211 are merely examples. Those skilled in the art can adjust the parameters according to actual needs to further determine the relationship between the step parameter H1 and the height position parameter H2 of the coil 122.

[0056] In some embodiments, a step parameter H1 that is too small can reduce the contact area between the coil support 121 and the coil 122, resulting in a loose connection between the two. A step parameter H1 that is too large can cause the portion of the inner coil 122-2 extending beyond the reference plane AA to be too long, causing most of the inner coil 122-2 to be outside the range of the strongest magnetic field, thus affecting the coil's sensitivity. Therefore, to ensure both a large contact area between the coil support 121 and the coil 122 and that most of the inner coil 122-2 is within the range of the strongest magnetic field, that is, to balance reliability and sensitivity, the step parameter H1 can be within a range of 0.1 mm to 0.8 mm. For example, the step parameter H1 can be within a range of 0.2 mm to 0.7 mm. For another example, the step parameter H1 can be within a range of 0.3 mm to 0.6 mm. For another example, the step parameter H1 can be within a range of 0.4 mm to 0.5 mm. For another example, the step parameter H1 can be within a range of 0.1 mm to 0.4 mm.

[0057] In some embodiments, in order to ensure that the coil support 121 has a certain mechanical strength and prevent the coil support 121 from being mechanically damaged by the vibration of the coil 122, the coil support 121 needs to have a certain thickness to maintain the mechanical strength of the coil support 121. At the same time, the coil support 121 has a certain thickness to facilitate processing. The distance between the lower step surface of the coil support 121 and the top of the coil support in the direction away from the docking (that is, the height of the lower step surface of the coil support 121 along the docking direction) H H As shown in Figure 2, the distance H between the higher step surface of the second step structure along the docking direction and the top of the coil support away from the docking direction is not less than 0.5mm. H It can be represented by the difference between the step parameter H1 and the height position parameter H2, that is, H H = H2-H1≥0.5mm. For example, the distance H between the higher step surface of the second step structure along the docking direction and the top of the coil support away from the docking direction is H For example, the distance H between the higher step surface of the second step structure along the docking direction and the top of the coil support away from the docking direction is not less than 0.6 mm. H Not less than 0.8mm.

[0058] In some embodiments, a height position parameter H2 that is too large or too small may cause the coil driving force factor BL value to decrease, affecting the sensitivity of the speaker 100. Therefore, in order to improve the sensitivity of the speaker 100, the value range of the height position parameter H2 can be within the range of 1.1 mm to 1.6 mm. For example, the value range of the height position parameter H2 can be within the range of 1.2 mm to 1.5 mm. For another example, the value range of the height position parameter H2 can be within the range of 1.3 mm to 1.4 mm.

[0059] In some embodiments, to prevent the bottom of the coil 122 from colliding with the bottom surface of the magnetic cover 211 due to a small distance between the bottom of the coil 122 and the bottom surface of the magnetic cover 211 during vibration, the distance between the bottom of the coil 122 and the bottom surface of the magnetic cover 211 along the extension direction of the coil support 121 may be no less than 0.9 mm. For example, the distance between the bottom of the coil 122 and the bottom surface of the magnetic cover 211 along the extension direction of the coil support 121 may be no less than 1 mm.

[0060] In some embodiments, a smaller magnetic gap results in a higher coil driving force factor BL value or sensitivity. However, if the magnetic gap is too small, the coil 122 may collide with the magnetic circuit assembly 110. Therefore, to achieve a higher coil driving force factor BL value or sensitivity while preventing the coil 122 from colliding with the magnetic circuit assembly 110, the radial gap between the coil 122 and the first magnet 212 may be within a range of 0.25 mm to 0.35 mm. For example, the radial gap between the coil 122 and the first magnet 212 may be within a range of 0.28 mm to 0.32 mm.

[0061] FIG3 is an exemplary structural diagram of another speaker according to some embodiments of this specification.

[0062] As shown in FIG3 , the coil assembly 120 may include a coil support 121 and a coil 122. The coil 122 includes an outer coil 122-1 and an inner coil 122-2. In some embodiments, the height of the inner coil 122-2 may be less than the height of the outer coil 122-1 along the extension direction of the coil support 121. As shown in FIG3 , taking the first step structure comprising two steps as an example, assuming that the AA section (the section at 1 / 2 of the height difference between the inner coil 122-2 and the outer coil 122-1 along the extension direction of the coil support 121) is used as the reference plane, the first step structure may include a raised portion and a recessed portion. The raised portion of the first step structure may be a step that passes vertically downward through the AA section (i.e., the portion of the coil support 121 near the inner coil 122-2 shown in FIG3 ), and the recessed portion of the first step structure may be a step that does not reach the AA section (i.e., the portion of the coil support 121 near the outer coil 122-1 shown in FIG3 ). The raised portion and the recessed portion of the first step structure are connected by a transition side parallel to the extension direction. In some embodiments, the raised portion of the first step structure can contact the inner coil 122-2, the recessed portion of the first step structure can contact the outer coil 122-1, and the transition side surface between the raised portion and the recessed portion of the first step structure contacts the outer coil 122-1 of coil 122. The second step structure can also include a raised portion and a recessed portion. The raised portion of the second step structure can be a step that passes vertically upward through the AA cross section (i.e., the portion of the outer coil 122-1 near the coil support 121 in Figure 3). In some embodiments, the raised portion of the second step structure contacts the recessed portion of the first step structure. The recessed portion of the second step structure can be a step lower than the AA cross section (i.e., the portion of the inner coil 122-2 near the coil support 121 in Figure 3). The raised portion of the second step structure and the recessed portion of the second step structure are connected by a transition side surface parallel to the extension direction. In some embodiments, the recessed portion of the second step structure contacts the raised portion of the first step structure, the raised portion of the second step structure contacts the recessed portion of the first step structure, and the transition portion of the second step structure contacts the transition portion of the first step structure. In some embodiments, the first step structure and the second step structure can be bonded together by gluing. For example, the first step structure and the second step structure can be bonded together by gluing together using an adhesive such as silicone.In this embodiment, the height of the inner coil 122-2 is set to be smaller than the height of the outer coil 122-1, and the first step structure of the coil support 121 is set at the same time, so that the coil 122 and the coil support 121 not only have contact areas at the raised part and the recessed part respectively, but also contact each other at the transition side surfaces of the two step structures. Therefore, it can achieve a function similar to the step structure in Figure 2, that is, increase the contact area between the coil support 121 and the coil 122, improve the firmness of the combination of the coil support 121 and the coil 122, and reduce the possibility of the coil 122 falling off from the coil support 121 along the extension direction during vibration; in addition, the coil support 121 can constitute a stress constraint on the coil 122 in the radial direction, thereby avoiding the dislocation of the coil 122 in the radial direction during vibration.

[0063] Fig. 4 is an exemplary structural diagram of another speaker according to some embodiments of the present specification. Fig. 5 is an exemplary structural diagram of another speaker according to some embodiments of the present specification.

[0064] As shown in Figures 4 or 5, the magnetic circuit assembly 110 may include a magnetic shield 211, a first magnet 212, a second magnet 413, and a magnetic plate 415. In some embodiments, the magnetic plate 415 is located between the first magnet 212 and the second magnet 413, and the magnetic properties of the first magnet 212 and the second magnet 413 are opposite. Placing the magnetic plate 415 between the first magnet 212 and the second magnet 413, which have opposite magnetic properties, maximizes the magnetic flux density and magnetic field strength on both sides of the magnetic plate 415 in the radial direction. When the areas with the highest density of coil 122 are located on both sides of the magnetic plate 415 in the radial direction, the coil driving force factor BL is greater, thereby increasing the sensitivity of the speaker 100. In some embodiments, the first magnet 212, the magnetic plate 415, and the second magnet 413 may be connected by connectors (e.g., screws). The coil assembly 120 may include a coil support 121 and a coil 122. The coil 122 includes an outer coil 122-1 and an inner coil 122-2.

[0065] In some embodiments, along the extension direction of the coil support 121, the height of the inner coil 122-2 is greater than the height of the outer coil 122-1. See Figure 2, which will not be repeated here. In some embodiments, the width of the outer coil 122-1 in the radial direction is wider than the width of the inner coil 122-2 in the radial direction. For example, the width of the raised portion of the second step structure in Figure 4 (i.e., the inner coil 122-2) in the radial direction can be smaller than the width of the recessed portion of the second step structure (i.e., the outer coil 122-1) in the radial direction. Correspondingly, the width of the recessed portion of the first step structure can be smaller than the width of the raised portion of the first step structure to achieve close contact between the coil support 121 and the coil 122. In some embodiments, the width of the coil 122 in the radial direction can be 0.6 mm, and the sum of the width of the outer coil 122-1 in the radial direction and the width of the inner coil 122-2 in the radial direction can be 0.6 mm. For example, the width of the outer coil 122-1 in the radial direction can be 0.4 mm, and the width of the inner coil 122-2 in the radial direction can be 0.2 mm. Correspondingly, the width of the raised portion of the first step structure in the radial direction can be 0.4 mm, and the width of the recessed portion of the first step structure in the radial direction can be 0.2 mm. The step structure of the coil 122 shown in Figure 4 can increase the contact area between the coil support 121 and the coil 122, improve the firmness of the combination of the coil support 121 and the coil 122, reduce the possibility of the coil 122 falling off from the coil support 121 along the extension direction during vibration, and improve the reliability of the speaker 100.

[0066] As shown in Figure 5, the width of the raised portion of the second step (i.e., the outer coil 122-1) in the radial direction can be greater than the width of the recessed portion of the second step (i.e., the inner coil 122-2) in the radial direction. Correspondingly, the width of the recessed portion of the first step is greater than the width of the raised portion of the first step to achieve close contact between the coil support 121 and the coil 122. In some embodiments, the width of the coil 122 in the radial direction can be 0.6mm, then the sum of the width of the outer coil 122-1 in the radial direction and the width of the inner coil 122-2 in the radial direction can be 0.6mm. For example, the width of the outer coil 122-1 in the radial direction can be 0.4mm, and the width of the inner coil 122-2 in the radial direction can be 0.2mm. Correspondingly, the width of the raised portion of the first step structure in the radial direction can be 0.2mm, and the width of the recessed portion of the first step structure in the radial direction can be 0.4mm. By setting the width of the outer coil 122-1 in the radial direction to be larger than the width of the inner coil 122-2 in the radial direction (as shown in Figure 5), a larger part of the coil 122 can be located in the area with the largest magnetic field intensity, making the coil driving force factor BL larger, and thus making the sensitivity of the speaker 100 greater.

[0067] In this embodiment, by adjusting the radial widths of outer coil 122-1 and inner coil 122-2, coil 122 can be more adaptable to various coil holders 121 (e.g., coil holders with stepped structures of varying radial widths). Adjustment of the coil width can be accomplished through different winding methods. In some embodiments, to ensure high reliability of speaker 100, inner coil 122-2 may have at least three turns.

[0068] It should be noted that the step-structure coils provided in Figures 2 to 5 of this specification are for illustration only and are not intended to limit the number of steps. For example, the step-structure coil may also have a structure including 3 steps, 4 steps, etc. The corresponding coil support may also have a structure including 3 steps, 4 steps, etc. For another example, the transition surface in the step structure may form any angle with the recessed portion or the raised portion (not limited to 90° in Figures 2 to 5). For another example, the width of the inner coil 122-2 in the radial direction may be greater than the width of the outer coil 122-1 in the radial direction, which can also achieve the effect of increasing the contact area between the coil support 121 and the coil 122. At this time, when the height of the inner coil 122-2 is greater than the height of the outer coil 122-1 along the extension direction of the coil support 121, a larger portion of the coil 122 is located in the area with the greatest magnetic field intensity, making the coil driving force factor BL larger, thereby increasing the sensitivity of the speaker 100.

[0069] FIG. 6 is a relationship curve between the coil driving force factor BL and the height position parameter H2 under different step parameters H1 according to some embodiments of this specification.

[0070] As shown in Figure 6, when either the step parameter H1 or the height position parameter H2 changes, the coil driving force factor BL changes. Curve 410 shows the relationship between the height position parameter H2 and the coil driving force factor BL when the step parameter H1 is 0.1 mm. As the height position parameter H2 increases, the coil driving force factor BL first increases to a peak value and then gradually decreases. Testing has shown that the coil driving force factor BL is higher when the height position parameter H2 is between 1.1 mm and 1.6 mm, indicating that the coil within this range has a higher sensitivity. Curves 420, 430, 440, 450, 460, 470, and 480 can be found in the description of curve 410. It should be noted that as the step parameter H1 increases, the room for the coil driving force factor BL to grow decreases. For example, in curves 460, 470, and 480, the curve segments where the coil driving force factor BL increases with increasing height position parameter H2 are relatively short, meaning that the coil driving force factor BL quickly reaches its peak value and then begins to decline.

[0071] As shown in Figure 6, when the height position parameter H2 is constant, the larger the step parameter H1, the smaller the peak value of the coil driving force factor BL. The peak values ​​of the coil driving force factor BL decrease in curves 410, 420, 430, 440, 450, 460, 470, and 480, respectively. Testing shows that the coil driving force factor BL is higher when the step parameter H1 is between 0.1 mm and 0.4 mm, indicating that the coil sensitivity within this range is higher.

[0072] It can be seen from the above curve relationship that in order to improve the sensitivity of the coil (i.e., the coil driving force factor BL), the height of the second step structure of the coil (i.e., the step parameter H1) can be minimized while ensuring the reliability of the coil, and the distance between the reference plane and the top of the coil bracket in the direction away from the docking (i.e., the height position parameter H2) can be selected in the range of 1.1mm to 1.6mm.

[0073] Fig. 7 is a radial cross-sectional view of a coil according to some embodiments of the present disclosure. The radial direction of the coil refers to the direction from the center of the coil outward.

[0074] In some embodiments, in order to ensure the bonding strength inside the coil 122 and between the coil 122 and the coil support 121, and to further improve the bonding reliability, the coil 122 can adopt a high-tension wire with a glue layer. It should be understood that the high-tension wire described in this specification refers to a wire whose elongation of the coil 122 is greater than a certain threshold (for example, 20%). For example, the elongation of the high-tension wire can be 20%, 30%, 40%, etc. In some embodiments, the high-tension wire can be made of copper alloy wire. Exemplary copper alloy wires can include nickel-copper alloy wire, zirconium-copper alloy wire, etc. In some embodiments, the coil 122 can be implemented by the coil 700 shown in Figure 7.

[0075] In some embodiments, as shown in FIG7 , the coil 700 may include a conductor 710, an insulating layer 720, and a glue layer 730 from the inside to the outside in the radial direction of the coil 700. In some embodiments, the diameter of the high-tension wire may be in the range of 0.08 mm to 0.12 mm. For example, the diameter of the high-tension wire may be 0.1 mm. In some embodiments, the sum of the thicknesses of the insulating layer 720 and the glue layer 730 along the radial direction of the coil 700 (i.e., the film thickness) may be no less than 0.016 mm. For example, the thickness of the insulating layer 720 along the radial direction of the coil 700 may be no less than 0.008 mm, and the thickness of the glue layer 730 along the radial direction of the coil 700 may be no less than 0.008 mm.

[0076] Conductor 710 refers to the portion of coil 700 used for conducting electricity. Exemplary conductors may include copper wire, aluminum wire, copper-clad aluminum wire, copper alloys, etc. Insulation layer 720 refers to the portion coated or wrapped around conductor 710 for electrical insulation. Exemplary insulation layer materials may include polyethylene, polyvinyl chloride, cross-linked polyethylene, a natural rubber-styrene-styrene rubber mixture, ethylene propylene rubber, butyl rubber, etc.

[0077] Glue layer 730, also known as a self-melting layer, may be an adhesive layer attached to insulating layer 720 by coating, soaking, or the like. Glue layer 730 is located at the outermost layer of coil 700. Exemplary glue layer materials may include polyvinyl butyral resin, modified polyamide, alcohol-modified polyamide, hot-air adhesive polyamide, and the like.

[0078] In the speaker 100 described in some embodiments of this specification, the elongation of the coil 122 is greater than a certain threshold (for example, 20%), so that the bonding between the coil 122 and the coil bracket 121 is more stable, the firmness of the combination between the coil bracket 121 and the coil 122 is improved, and the possibility of the coil 122 falling off from the coil bracket 121 along the extension direction during vibration is reduced, thereby increasing the reliability of the speaker 100.

[0079] FIG. 8 is a schematic diagram of coil arrangement according to some embodiments of the present disclosure.

[0080] In some embodiments, the coil can be pre-stretched before winding. Pre-stretching can fully extend the coil and improve the shape stability of the coil after winding. Pre-stretching can allow the coil to extend to a certain extent based on the elongation (such as the copper alloy wire with an elongation of not less than 20% provided in this specification), avoiding the wire from being further extended under the action of external forces during later use, thereby destroying the winding stability. In addition, pre-stretching increases the pressure and friction between the coil layers, further improving the shape stability of the coil.

[0081] Figure 8 is a schematic diagram of the wiring arrangement after rotating the right half of the stepped coil structure in Figure 2 counterclockwise by 90°. As shown in Figure 8 , the wire of coil 122 begins at number 1 and winds around a magnet (e.g., first magnet 212), winding back and forth three times to number 53 (the first layer of wires is from numbers 1 to 18, the second layer is from numbers 19 to 35, and the third layer is from numbers 36 to 53). The coils numbered 1 to 53 serve as inner coil 122-2. The height of the fourth, fifth, and sixth layers is then controlled by extending the left positioning mold 810 by a specific length (e.g., the specific length can be twice the step parameter H1). The coils are then wound back three times from number 54 to number 79. The coils numbered 54 to 79 serve as outer coil 122-1. In some embodiments, by controlling the number of layers of the outer and inner coils, the radial widths of the outer and inner coils can be controlled. For example, the inner coil 122-2 of the coil 122 in Figure 4 can be a coil composed of the first and second layers, and the outer coil 122-1 can be a coil composed of the third, fourth, fifth, and sixth layers. The above-mentioned wiring process can prevent misalignment or unevenness within the layer at the step, ensuring the shape stability of the step.

[0082] Similarly, for the coil with a step structure in Figure 3, the winding method can be to first extend the positioning mold 810 along the first magnet 212 to a specific length (for example, the specific length can be 2 times the step parameter H1) to control the height of the first, second, and third layers, and perform the winding of the first, second, and third layers. Then put the coil holder in and perform the winding of the fourth, fifth, and sixth layers. In some embodiments, by controlling the number of layers of the outer coil and the inner coil, the width of the outer coil and the inner coil in the radial direction can be controlled. For example, the inner coil 122-2 of the coil 122 in Figure 5 can be a coil composed of the first and second layers, and the outer coil 122-1 can be a coil composed of the third, fourth, fifth, and sixth layers.

[0083] It should be noted that the number of coil layers and coil numbers in Figure 8 are for ease of explanation only and are not intended to limit the number of coil layers or the number of turns of the coil. For example, the coil can be wound with 5 layers, 8 layers, 18 layers, etc. The number of coil turns can be 100, 101, 150, etc.

[0084] The beneficial effects that may be brought about by the embodiments of this specification include but are not limited to: (1) by providing a coil and a coil support with a step structure, the contact area between the coil and the coil support is increased, the stability of the coil is improved, and the possibility of radial misalignment of the coil is reduced; (2) pre-stretching before winding increases the pressure and friction between the coil layers, so that the internal bonding strength of the coil is improved and the space utilization rate is improved; (3) high-tension wire is used as the coil wire material, and the glue layer on the surface of the high-tension wire is used to enhance the bonding strength between the coil and the coil support, as well as the firmness of the stacking between the contacting wires in the coil. 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.

[0085] 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.

[0086] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0087] Similarly, it should be noted that, in order to simplify the presentation of this application and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this application sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not mean that the subject matter of this application requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single embodiment disclosed above.

[0088] 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 variations may also fall within the scope of this application. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this application may be considered consistent with the teachings of this application. Accordingly, the embodiments of this application are not limited to the embodiments explicitly introduced and described in this application.

Claims

1. A speaker, comprising: Magnetic circuit components; The coil assembly is at least partially located in the magnetic gap formed by the magnetic circuit assembly. When the coil assembly is energized, it drives the vibrator to vibrate to generate sound, wherein the coil assembly includes: a coil support, the coil support having an extending end extending toward the magnetic gap, the extending end having a first step structure; and The coil comprises an outer coil and an inner coil, and in the direction close to the coil support, the outer coil and the inner coil form a second step structure, and the first step structure and the second step structure are connected to each other so that the coil is fixedly installed on the coil support.

2. The loudspeaker according to claim 1, characterized in that In the extension direction of the coil support, the height of the inner coil is greater than the height of the outer coil.

3. The loudspeaker according to claim 1, characterized in that In the extension direction of the coil support, the height of the inner coil is smaller than the height of the outer coil.

4. The loudspeaker according to any one of claims 1 to 3, characterized in that: The inner coil and the outer coil have the same width in the radial direction.

5. The loudspeaker according to any one of claims 1 to 3, characterized in that: The width of the outer coil in the radial direction is wider than the width of the inner coil in the radial direction.

6. The loudspeaker according to any one of claims 1 to 5, characterized in that: The coil is a metal wire with an elongation of not less than 20%.

7. The loudspeaker according to any one of claims 1 to 6, characterized in that: The coil comprises a conductor, an insulating layer and a glue layer from inside to outside in the radial direction of the coil, and the total thickness of the insulating layer and the glue layer in the radial direction is not less than 0.016 mm.

8. The loudspeaker according to any one of claims 1 to 7, characterized in that: The step parameter H1 and height position parameter H2 of the coil satisfy the following conditions: H1+0.5mm≤H2≤1.8mm, wherein the step parameter H1 is 1 / 2 of the height difference between the inner coil and the outer coil along the extension direction of the coil bracket, the height position parameter H2 is the distance between the reference plane and the top of the coil bracket away from the docking direction, and the reference plane is the plane where 1 / 2 of the height difference between the inner coil and the outer coil along the extension direction of the coil bracket is located.

9. The loudspeaker according to claim 8, characterized in that The step parameter H1 is in the range of 0.1 mm to 0.8 mm.

10. The loudspeaker according to claim 8 or claim 9, characterized in that: The height position parameter H2 is in the range of 1.1 mm to 1.6 mm.

11. The loudspeaker according to any one of claims 1 to 10, characterized in that: The distance between the lower step surface of the coil support and the top of the coil support in the direction away from the docking direction is not less than 0.5 mm.

12. The loudspeaker according to any one of claims 1 to 11, characterized in that: The magnetic circuit assembly includes a first magnet and a magnetic conductive cover at least partially surrounding the first magnet. Along the extension direction of the coil support, the distance between the bottom of the coil and the bottom surface of the magnetic conductive cover is not less than 0.9 mm.

13. The loudspeaker according to claim 12, characterized in that A gap between the coil and the first magnet in a radial direction is in the range of 0.25 mm to 0.35 mm.

14. The loudspeaker according to claim 12 or claim 13, characterized in that: The magnetic circuit assembly also includes a second magnet and a magnetic conductive plate. The magnetic conductive plate is located between the first magnet and the second magnet, and the magnetic properties of the first magnet and the second magnet are opposite.

15. A loudspeaker, comprising: Magnetic circuit components; The coil assembly is at least partially located in the magnetic gap formed by the magnetic circuit assembly. When the coil assembly is energized, it drives the vibrator to vibrate to generate sound, wherein the coil assembly includes: a coil support having an extending end extending toward the magnetic gap; and The coil comprises an outer coil and an inner coil, and in a direction close to the coil support, the outer coil and the inner coil form a step structure, and the coil is a metal wire with an elongation of not less than 20%.

16. The loudspeaker according to claim 15, characterized in that The coil comprises a conductor, an insulating layer and a glue layer from inside to outside in the radial direction of the coil, and the total thickness of the insulating layer and the glue layer in the radial direction is not less than 0.016 mm.

17. The loudspeaker according to claim 15 or claim 16, characterized in that: In the extension direction of the coil support, the height of the inner coil is greater than the height of the outer coil.

18. The loudspeaker according to claim 15 or claim 16, characterized in that: In the extension direction of the coil support, the height of the inner coil is smaller than the height of the outer coil.

19. The loudspeaker according to any one of claims 15 to 18, characterized in that: The inner coil and the outer coil have the same width in the radial direction.

20. The loudspeaker according to any one of claims 15 to 18, characterized in that: The width of the outer coil in the radial direction is wider than the width of the inner coil in the radial direction.

21. The loudspeaker according to any one of claims 15 to 20, characterized in that: The step parameter H1 and height position parameter H2 of the coil satisfy the following conditions: H1+0.5mm≤H2≤1.8mm, wherein the step parameter H1 is 1 / 2 of the height difference between the inner coil and the outer coil along the extension direction of the coil bracket, the height position parameter H2 is the distance between the reference plane and the top of the coil bracket away from the docking direction, and the reference plane is the plane where 1 / 2 of the height difference between the inner coil and the outer coil along the extension direction of the coil bracket is located.

22. The loudspeaker according to claim 21, characterized in that The step parameter H1 is in the range of 0.1 mm to 0.8 mm.

23. The loudspeaker according to claim 21 or claim 22, characterized in that The height position parameter H2 is in the range of 1.1 mm to 1.6 mm.

24. The loudspeaker according to any one of claims 15 to 23, characterized in that: The extended end of the coil support has a second step structure, and the second step structure is connected with the outer coil and the inner coil to form a step structure, so that the coil is fixedly installed on the coil support.

25. The loudspeaker according to claim 24, characterized in that The distance between the lower step surface of the coil support and the top of the coil support in the direction away from the docking direction is not less than 0.5 mm.

26. The loudspeaker according to any one of claims 15 to 25, characterized in that: The magnetic circuit assembly includes a first magnet and a magnetic conductive cover at least partially surrounding the first magnet. Along the extension direction of the coil support, the distance between the bottom of the coil and the bottom surface of the magnetic conductive cover is not less than 0.9 mm.

27. The loudspeaker according to claim 26, characterized in that A gap between the coil and the first magnet in a radial direction is in the range of 0.25 mm to 0.35 mm.

28. The loudspeaker according to claim 26 or claim 27, characterized in that The magnetic circuit assembly also includes a second magnet and a magnetic conductive plate. The magnetic conductive plate is located between the first magnet and the second magnet, and the magnetic properties of the first magnet and the second magnet are opposite.

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