CN111327999B

CN111327999B - Loudspeaker box

Info

Publication number: CN111327999B
Application number: CN202010148711.9A
Authority: CN
Inventors: 令狐荣林; 肖波; 章统
Original assignee: AAC Technologies Pte Ltd
Current assignee: AAC Technologies Pte Ltd
Priority date: 2020-03-05
Filing date: 2020-03-05
Publication date: 2021-02-19
Anticipated expiration: 2040-03-05
Also published as: CN111327999A; WO2021174573A1

Abstract

The invention provides a loudspeaker box capable of improving effective vibration area, which comprises a box body with a containing cavity and a sound production device, wherein the containing cavity is divided into a front cavity and a rear cavity by a partition plate, the partition plate is provided with a monomer leakage hole communicated with the rear cavity, the box body is provided with a sound outlet hole communicated with the front cavity in a penetrating way, the sound production device is suspended in the front cavity and comprises a basin frame, a vibration system and a magnetic circuit system, the basin frame is provided with a first leakage hole and a second leakage hole communicated with the monomer leakage hole, the vibration system comprises an upper vibration film and a lower vibration film which are respectively fixed on two opposite sides of the basin frame and have opposite vibration directions, an upper voice coil driving the upper vibration film to vibrate and produce sound, a lower voice coil driving the lower vibration film to vibrate and produce sound and a framework connecting the lower voice coil and the lower vibration film, the upper vibration film, the lower vibration film and the basin frame enclose and form an accommodating space for accommodating the magnetic circuit system, the magnetic circuit system divides the accommodating space into an upper cavity communicated with, and the upper cavity and the lower cavity are not communicated with each other.

Description

Loudspeaker box

[ technical field ] A method for producing a semiconductor device

The invention relates to the field of acoustoelectric, in particular to a loudspeaker box applied to portable electronic products.

[ background of the invention ]

With the advent of the mobile internet age, the number of smart mobile devices is increasing. Among the mobile devices, the mobile phone is undoubtedly the most common and portable mobile terminal device. At present, the functions of a mobile phone are very diverse, one of which is a high-quality music function, and thus, a speaker box for playing sound is widely applied to the current smart mobile devices.

The loudspeaker box comprises a box body with a containing cavity and a sound production device arranged in the box body, and a sound hole penetrates through the box body. The sound-generating device in the related art has only one sound-generating surface, and thus is not favorable for improving the sensitivity of the speaker box.

Therefore, there is a need to provide a new speaker box to solve the above technical problems.

[ summary of the invention ]

The invention aims to provide a loudspeaker box, which can improve the effective vibration area and improve the sensitivity of the loudspeaker box.

In order to achieve the above object, the present invention provides a loudspeaker box, comprising a box body having a receiving cavity and a sound generating device, wherein a partition plate is arranged in the box body and divides the receiving cavity into a front cavity and a rear cavity, the box body is provided with a sound outlet communicated with the front cavity in a penetrating manner, the partition plate is provided with a single leakage hole communicated with the rear cavity in a penetrating manner, the sound generating device is suspended in the front cavity, the sound generating device comprises a basin frame abutted against the partition plate, a vibration system fixed on the basin frame and a magnetic circuit system for driving the vibration system to vibrate and generate sound, the basin frame is provided with a first leakage hole and a second leakage hole communicated with the single leakage hole in a penetrating manner, the vibration system comprises an upper vibration membrane and a lower vibration membrane which are fixed on two opposite sides of the basin frame and have opposite vibration directions, an upper voice coil for driving the upper vibration to generate sound and a lower voice coil for driving the lower vibration membrane to vibrate and generate sound, the upper diaphragm, the lower diaphragm and the basin frame are enclosed to form an accommodating space for accommodating the magnetic circuit system, the magnetic circuit system comprises a first magnetic part, a second magnetic part which is arranged around the first magnetic part and forms an inner magnetic gap with the first magnetic part, a third magnetic part which is arranged around the second magnetic part and forms an outer magnetic gap with the second magnetic part, a first pole core which is fixedly arranged on one side of the first magnetic part facing the upper diaphragm, a second pole core which is fixedly arranged on one side of the second magnetic part and the third magnetic part facing the upper diaphragm, and a third pole core which is fixedly arranged on one side of the first magnetic part and the second magnetic part facing the lower diaphragm, the second magnetic part is in a continuous annular structure, the second pole core is fixedly arranged on the basin frame, the upper voice coil is inserted into the inner magnetic gap, and the lower voice coil is inserted into the outer magnetic gap, the second pole core, the third pole core and the second magnetic part divide the accommodating space into an upper cavity communicated with the first leakage hole and a lower cavity communicated with the second leakage hole.

Preferably, the second leakage hole is located at a position of the basin frame corresponding to the magnetic circuit system, and the third magnetic part is provided with a leakage channel communicating the outer magnetic gap and the second leakage hole.

Preferably, the third magnetic part is composed of a plurality of third permanent magnets arranged around the second magnetic part, and two adjacent third permanent magnets are arranged at intervals, wherein two adjacent third permanent magnets of the second leakage hole are arranged at intervals to form the leakage channel.

Preferably, the lower voice coil and the lower vibrating diaphragm are connected through a framework, and the framework comprises a first connecting part connected with the lower vibrating diaphragm, a second connecting part connected with the lower voice coil and a third connecting part connected with the first connecting part and the second connecting part.

Preferably, the first connecting portion and the second connecting portion are both in a ring structure.

Preferably, the framework is an integrally formed structure.

Preferably, the vibration system further includes an upper dome and a lower dome disposed in the accommodating space, the upper dome is connected to the upper diaphragm and the upper voice coil along opposite sides in the vibration direction, and the lower dome is connected to the first connecting portion and the lower diaphragm along opposite sides in the vibration direction.

Preferably, the magnetic circuit system further comprises a fourth pole core fixed on one side of the third magnetic part facing the lower diaphragm, and the fourth pole core is fixed on the basin frame.

Preferably, the sounder further comprises an upper end cover and a lower end cover, the upper vibrating diaphragm clamp is arranged between the basin frame and the upper end cover, the upper end cover is provided with a first sounding hole for the outward sounding of the upper vibrating diaphragm, the lower vibrating diaphragm clamp is arranged between the basin frame and the lower end cover, and the lower end cover is provided with a second sounding hole for the outward sounding of the lower vibrating diaphragm.

Preferably, the box body comprises an upper bottom surface and a lower bottom surface, the upper bottom surface is opposite to the upper end cover and is arranged at an interval, the lower bottom surface is opposite to the lower end cover and is arranged at an interval, a plurality of first cushion blocks for supporting the upper end cover are arranged on the upper bottom surface, and a plurality of second cushion blocks for supporting the lower end cover are arranged on the lower bottom surface.

Compared with the prior art, the loudspeaker box has the advantages that the upper vibrating diaphragm and the lower vibrating diaphragm are arranged to be opposite in vibrating direction and driven by the upper voice coil and the lower voice coil respectively, and the sound generating device is arranged to be suspended in the front cavity, so that sound generated by the vibration of the upper vibrating diaphragm and the lower vibrating diaphragm is transmitted to the outside of the loudspeaker box through the sound outlet, and the effective vibrating area of the loudspeaker box is greatly increased, and the sensitivity of the loudspeaker box is improved; and simultaneously, go up the vibrating diaphragm with during the vibrating diaphragm vibration down, the internal air current of epicoele can pass through first leakage hole with monomer leakage hole with the back chamber circulation, the internal air current of cavity can pass through down the second leakage hole with monomer leakage hole with the back chamber circulation. Through the structural design of the magnetic circuit system, the upper cavity and the lower cavity are not communicated with each other, so that the upper vibrating diaphragm and the lower vibrating diaphragm are not influenced by each other in the vibrating process. In addition, the upper voice coil and the lower voice coil are respectively inserted into the inner magnetic gap and the outer magnetic gap of the magnetic circuit system, so that the upper vibrating diaphragm and the lower vibrating diaphragm share the magnetic circuit system, and the utilization rate of a magnetic circuit is improved.

[ description of the drawings ]

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:

FIG. 1 is a perspective view of a preferred embodiment of a speaker cabinet of the present invention;

FIG. 2 is a cross-sectional view of the loudspeaker enclosure of FIG. 1 taken along the direction A-A;

FIG. 3 is a cross-sectional view of the loudspeaker enclosure of FIG. 1 taken along the direction B-B;

FIG. 4 is a schematic structural view of a sound producing device in the loudspeaker enclosure of FIG. 2;

FIG. 5 is a schematic view of the sound producing device in the speaker box of FIG. 3;

FIG. 6 is an exploded perspective view of the sound device of FIG. 5;

FIG. 7 is an assembled structural view of a portion of the sound device shown in FIG. 6;

FIG. 8 is a schematic assembled magnetic circuit of the sounder device illustrated in FIG. 6;

fig. 9 is a schematic structural view of another angle of the magnetic circuit system shown in fig. 8.

[ detailed description ] embodiments

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 9, the speaker box includes a box body 100 having a receiving cavity 100A and a sound generating device 200 disposed in the box body 100.

The sound production device is characterized in that a partition plate 101 which divides the accommodating cavity 100A into a front cavity 100B and a rear cavity 100C is arranged in the box body 100, a single leakage hole 102 communicated with the rear cavity 100C is arranged in the partition plate 101 in a penetrating mode, a sound outlet hole 103 communicated with the front cavity 100B is arranged in the box body 100 in a penetrating mode, and the sound production device 200 is suspended in the front cavity 100B.

The sounder 200 includes a frame 1 abutting against the partition 101, a vibration system 3 fixed on the frame 1, and a magnetic circuit system 5 for driving the vibration system 3 to vibrate and sound.

The basin stand 1 is in a rectangular structure. The basin frame 1 is provided with a first leakage hole 1A and a second leakage hole 1B which are communicated with the single leakage hole 102 in a penetrating manner. Specifically, the first leakage hole 1A and the second leakage hole 1B are located on the side wall of the frame 1 abutting against the partition plate 101 so that the first leakage hole 1A and the second leakage hole 1B communicate with the unit leakage hole 102.

As shown in fig. 2, the monomer leakage holes 102 include a first monomer leakage hole 102A communicated with the first leakage hole 1A and a second monomer leakage hole 102B communicated with the second leakage hole 1B, and the first monomer leakage hole 102A and the second monomer leakage hole 102B are arranged at intervals. Of course, in other embodiments, the first unit leakage hole 102A and the second unit leakage hole 102B may be opened to form a single leakage hole.

Vibration system 3 includes last vibrating diaphragm 31, lower vibrating diaphragm 33, goes up voice coil 34, lower voice coil 35 and skeleton 36, go up vibrating diaphragm 31 with lower vibrating diaphragm 33 is fixed in respectively the relative both sides of basin frame 1, just go up vibrating diaphragm 31 with the vibration opposite direction of lower vibrating diaphragm 33, go up vibrating diaphragm 31 down vibrating diaphragm 33 reaches basin frame 1 encloses and closes formation accommodating space 200A, magnetic circuit 5 accept in accommodating space 200A, just magnetic circuit 5 will accommodating space 200A separate for with the last cavity 200B of first leakage hole 1A intercommunication and with the lower cavity 200C of second leakage hole 1B intercommunication, go up voice coil 34 drive go up vibrating diaphragm 31 vibration sound production, voice coil 35 drive down vibrating diaphragm 33 vibration sound production, skeleton 36 is connected down voice coil 35 with lower vibrating diaphragm 33.

It should be noted that the vibration directions of the upper diaphragm 31 and the lower diaphragm 33 are opposite to each other, which means that the instantaneous vibration directions are opposite to each other. Specifically, when the upper diaphragm 31 vibrates in a direction away from the magnetic circuit 5, the lower diaphragm 33 also vibrates in a direction away from the magnetic circuit 5; when the upper diaphragm 31 vibrates in a direction approaching the magnetic circuit 5, the lower diaphragm 33 also vibrates in a direction approaching the magnetic circuit 5.

The bobbin 36 includes a first connection portion 361 connected to the lower diaphragm 33, a second connection portion 362 connected to the lower voice coil 35, and a third connection portion 363 connecting the first connection portion 361 and the second connection portion 362.

In this embodiment, the first connecting portion 361 and the second connecting portion 362 are both in a ring structure. It is to be understood that the first connection portion 361 and the second connection portion 362 are not limited to this embodiment; for example, in other embodiments, the first connecting portion 361 may be configured to have a flat plate shape; the second connection portion 362 may be formed of a plurality of separate structures, and each separate structure may be connected to the lower voice coil 35.

In this embodiment, the frame 36 is an integrally formed structure. It is understood that, in other embodiments, the first connection portion 361, the second connection portion 362 and the third connection portion 363 may be formed by welding.

In order to enhance the vibration effect of the upper diaphragm 31 and the lower diaphragm 35 to improve the acoustic performance of the sounder device 200. In this embodiment, the vibration system 3 further includes an upper dome 37 and a lower dome 38 disposed in the receiving space 200A, two opposite sides of the upper dome 37 along the vibration direction X are respectively connected to the upper diaphragm 31 and the upper voice coil 34, and two opposite sides of the lower dome 38 along the vibration direction X are respectively connected to the first connecting portion 361 and the lower diaphragm 33. It is understood that, in other embodiments, the upper dome 37 and the lower dome 38 may also be disposed outside the receiving space 200A, and two opposite sides of the upper diaphragm 31 along the vibration direction X are respectively connected to the upper voice coil 34 and the upper dome 37, and two opposite sides of the lower diaphragm 33 along the vibration direction X are respectively connected to the lower dome 38 and the first connecting portion 361.

As shown in fig. 4, 5 and 6, the sound generating device 200 further includes an upper end cover 7 and a lower end cover 9, the upper diaphragm 31 is clamped between the basin frame 1 and the upper end cover 7, the upper end cover 7 has a first sound emitting hole 71 for the upper diaphragm 31 to emit sound outwards, the lower diaphragm 33 is clamped between the basin frame 1 and the lower end cover 9, and the lower end cover 9 has a second sound emitting hole 91 for the lower diaphragm 33 to emit sound outwards. The upper end cover 7 and the lower end cover 9 are arranged, so that the upper vibrating diaphragm 31 and the lower vibrating diaphragm 33 can be better fixed on the frame 1.

In this embodiment, the box 100 includes an upper bottom surface 104 opposite to the upper cover 7 and disposed at an interval, and a lower bottom surface 105 opposite to the lower cover 9 and disposed at an interval, wherein the upper bottom surface 104 is provided with a plurality of first spacers 106 for supporting the upper cover 7, and the lower bottom surface 105 is provided with a plurality of second spacers 107 for supporting the lower cover 9. The sounder device 200 is suspended within the front cavity 100B by the support of the first plurality of blocks 106 and the second plurality of blocks 107. As shown in fig. 3, the first block 106 and the second block 107 are integrally formed with the box 100, it is understood that in other embodiments, the first block 106 may be a block fixed on the upper bottom surface 104, and the second block 107 may be a block fixed on the lower bottom surface 105.

The magnetic circuit system 5 includes a first magnetic part 51, a second magnetic part 52 surrounding the first magnetic part 51 and forming an inner magnetic gap 5A with the first magnetic part 51, a third magnetic part 53 surrounding the second magnetic part 52 and forming an outer magnetic gap 5B with the second magnetic part 52, a first pole piece 54 fixed on one side of the first magnetic part 51 facing the upper diaphragm 31, a second pole piece 55 fixed on one side of the second magnetic part 52 and the third magnetic part 53 facing the upper diaphragm 31, and a third pole piece 56 fixed on one side of the first magnetic part 51 and the second magnetic part 52 facing the lower diaphragm 33, wherein the second magnetic part 52 is in a continuous ring structure, the second pole piece 55 is fixed on the frame 1, the upper voice coil 34 is inserted into the inner magnetic gap 5A, and the lower voice coil 35 is inserted into the outer magnetic gap 5B, the second pole piece 55, the third pole piece 56 and the second magnetic part 52 divide the receiving space 200A into an upper cavity 200B communicating with the first leakage hole 1A and a lower cavity 200C communicating with the second leakage hole 1B. After the upper voice coil 34 is powered on, under the magnetic action of the magnetic circuit system 5, the upper diaphragm 31 vibrates together with the upper voice coil 34; after the lower voice coil 35 is powered on, the lower diaphragm 33 and the bobbin 36 vibrate together with the lower voice coil 35 under the magnetic force of the magnetic circuit system 5. Since the upper diaphragm 31 and the lower diaphragm 33 are arranged to vibrate in opposite directions and are driven by the upper voice coil 34 and the lower voice coil 35 to generate sound, respectively, and the sound generating device 200 is arranged to be suspended in the front cavity 100B, the sound generated by the vibration of the upper diaphragm 31 and the lower diaphragm 33 is transmitted to the outside of the speaker box through the sound outlet holes 103, so that the effective vibration area of the speaker box is greatly increased to improve the sensitivity of the speaker box; meanwhile, when the upper diaphragm 31 and the lower diaphragm 33 vibrate, the airflow in the upper cavity 200B can pass through the first leakage hole 1A and the single leakage hole 102 and the rear cavity 100C, and the airflow in the lower cavity 200C can pass through the second leakage hole 1B and the single leakage hole 102 and the rear cavity 100C. The magnetic circuit system 5 separates the upper cavity 200B and the lower cavity 200C by the second pole core 55, the third pole core 56 and the second magnetic part 52, so that the vibration processes of the upper diaphragm 31 and the lower diaphragm 33 do not affect each other. In addition, because the upper voice coil 34 and the lower voice coil 35 are respectively inserted into the inner magnetic gap 5A and the outer magnetic gap 5B of the magnetic circuit system 5, the upper diaphragm 31 and the lower diaphragm 33 share the same magnetic circuit system, and the utilization rate of the magnetic circuit is improved.

In the present embodiment, the magnetic circuit system 5 further includes a fourth pole core 57 fixed on the side of the third magnetic part 53 facing the lower diaphragm 33, and the fourth pole core 57 is fixed on the frame 1. Through the magnetic conduction effect of the first pole core 54, the second pole core 55, the third pole core 56 and the fourth pole core 57, the magnetic fluxes in the inner magnetic gap 5A and the outer magnetic gap 5B can be effectively increased, so that the acoustic performance of the sound production device 200 can be improved, and the sound production device 200 is also beneficial to the light and thin design. Meanwhile, since the second pole piece 55 and the fourth pole piece 57 are both fixed on the frame 1, the magnetic circuit system 5 can be better fixed on the frame 1.

In the present embodiment, the first pole piece 54 and the second pole piece 55 are located on the same horizontal plane, and the third pole piece 56 and the fourth pole piece 57 are also located on the same horizontal plane.

In this embodiment, the second leakage hole 1B is located at a position of the frame 1 corresponding to the magnetic circuit system 5, and the third magnetic part 53 has a leakage path 53A communicating the outer magnetic gap 5B and the second leakage hole 1B. That is, the second leak hole 1B communicates with the lower cavity 200C through the outer magnetic gap 5B and the leak passage 53A (i.e., the second leak hole 1B indirectly communicates with the lower cavity 200C). It is understood that in other embodiments, the second leakage hole 1B is located at a position of the frame 1 corresponding to the lower cavity 200C (i.e. the second leakage hole 1B directly communicates with the lower cavity 200C), and accordingly, the third magnetic part may not have a leakage path.

In this embodiment, the third magnetic part 53 is formed by a plurality of third permanent magnets surrounding the second magnetic part 52, and two adjacent third permanent magnets are spaced apart from each other. Wherein, two of the third permanent magnets adjacent to the second leakage hole 1B are disposed at an interval to form the leakage passage 53A. It is understood that, in other embodiments, the third magnetic part 53 may also be a third permanent magnet in an annular structure, and accordingly, a leakage passage communicating the outer magnetic gap and the second leakage hole needs to be opened at a position of the third permanent magnet corresponding to the second leakage hole.

In the present embodiment, the first magnetic part 51 is a first permanent magnet. It is understood that, in other embodiments, the first magnetic part 51 may also be formed by two, three, etc. first permanent magnets which are stacked along the vibration direction X, and a pole core may also be interposed between two adjacent first permanent magnets.

In the present embodiment, the second magnetic part 52 is a second permanent magnet. It is understood that, in other embodiments, the second magnetic part 52 may be formed by two, three, or other second permanent magnets in a continuous annular structure, which are stacked in the vibration direction X, and a pole core may be further sandwiched between two adjacent second permanent magnets.

The first permanent magnet, the second permanent magnet and the third permanent magnet are usually magnetic steels. It is to be understood that the first permanent magnet, the second permanent magnet, and the third permanent magnet may be natural magnets.

Compared with the related art, the loudspeaker box of the invention has the advantages that the upper vibrating diaphragm 31 and the lower vibrating diaphragm 33 are arranged to have opposite vibrating directions and are respectively driven by the upper voice coil 34 and the lower voice coil 35, and the sound generating device 200 is arranged to be suspended in the front cavity 100B, so that the sound generated by the vibration of the upper vibrating diaphragm 31 and the lower vibrating diaphragm 33 is transmitted to the outside of the loudspeaker box through the sound outlet hole 103, and the effective vibrating area of the loudspeaker box is greatly increased to improve the sensitivity of the loudspeaker box; meanwhile, when the upper diaphragm 31 and the lower diaphragm 33 vibrate, the airflow in the upper cavity 200B can pass through the first leakage hole 1A and the single leakage hole 102 and the rear cavity 100C, and the airflow in the lower cavity 200C can pass through the second leakage hole 1B and the single leakage hole 102 and the rear cavity 100C. Through the structural design of the magnetic circuit system 5, the upper cavity 200B and the lower cavity 200C are not communicated with each other, so that the upper diaphragm 31 and the lower diaphragm 33 are not influenced by each other in the vibration process. In addition, the upper voice coil 34 and the lower voice coil 35 are respectively inserted into the inner magnetic gap 5A and the outer magnetic gap 5B of the magnetic circuit system 5, so that the upper diaphragm 31 and the lower diaphragm 33 share the magnetic circuit system 5, thereby improving the utilization rate of the magnetic circuit.

While the foregoing is directed to embodiments of the present invention, it will be understood by those skilled in the art that various changes may be made without departing from the spirit and scope of the invention.

Claims

1. A loudspeaker box comprises a box body with a containing cavity and a sound production device, and is characterized in that a partition board which divides the containing cavity into a front cavity and a back cavity is arranged in the box body, a sound production hole communicated with the front cavity is arranged on the box body in a penetrating manner, a monomer leakage hole communicated with the back cavity is arranged on the partition board in a penetrating manner, the sound production device is suspended in the front cavity, the sound production device comprises a basin frame abutted against the partition board, a vibration system fixedly held on the basin frame and a magnetic circuit system for driving the vibration system to vibrate and produce sound, a first leakage hole and a second leakage hole which are communicated with the monomer leakage hole are arranged on the basin frame in a penetrating manner, the vibration system comprises an upper vibration film and a lower vibration film which are fixed on two opposite sides of the basin frame respectively and have opposite vibration directions, the upper vibration film and the lower vibration film drive the upper vibration film to vibrate and produce sound and the lower vibration film to produce sound, the upper diaphragm, the lower diaphragm and the basin frame are enclosed to form an accommodating space for accommodating the magnetic circuit system, the magnetic circuit system comprises a first magnetic part, a second magnetic part which is arranged around the first magnetic part and forms an inner magnetic gap with the first magnetic part, a third magnetic part which is arranged around the second magnetic part and forms an outer magnetic gap with the second magnetic part, a first pole core which is fixedly arranged on one side of the first magnetic part facing the upper diaphragm, a second pole core which is fixedly arranged on one side of the second magnetic part and the third magnetic part facing the upper diaphragm, and a third pole core which is fixedly arranged on one side of the first magnetic part and the second magnetic part facing the lower diaphragm, the second magnetic part is in a continuous annular structure, the second pole core is fixedly arranged on the basin frame, the upper voice coil is inserted into the inner magnetic gap, and the lower voice coil is inserted into the outer magnetic gap, the second pole core, the third pole core and the second magnetic part divide the accommodating space into an upper cavity communicated with the first leakage hole and a lower cavity communicated with the second leakage hole.

2. The speaker box according to claim 1, wherein the second leakage hole is located at a position of the frame corresponding to the magnetic circuit system, and the third magnetic part has a leakage path communicating the outer magnetic gap and the second leakage hole.

3. The loudspeaker enclosure of claim 2, wherein the third magnetic part is formed by a plurality of third permanent magnets disposed around the second magnetic part, and two adjacent third permanent magnets are disposed at intervals, wherein two adjacent third permanent magnets are disposed at intervals to form the leakage path.

4. The speaker box of claim 1, wherein the lower voice coil and the lower diaphragm are connected by a bobbin, and the bobbin comprises a first connecting portion connected with the lower diaphragm, a second connecting portion connected with the lower voice coil, and a third connecting portion connecting the first connecting portion and the second connecting portion.

5. A loudspeaker enclosure according to claim 4, wherein the first and second connections are each of annular configuration.

6. A loudspeaker enclosure according to claim 4 or claim 5, wherein the frame is of unitary construction.

7. The speaker box of claim 4, wherein the vibration system further comprises an upper dome and a lower dome disposed in the receiving space, the upper dome is connected to the upper diaphragm and the upper voice coil along opposite sides in the vibration direction, and the lower dome is connected to the first connection portion and the lower diaphragm along opposite sides in the vibration direction.

8. A loudspeaker enclosure according to claim 1, wherein the magnetic circuit further comprises a fourth pole core fixed to the third magnetic part on a side facing the lower diaphragm, the fourth pole core being fixed to the frame.

9. The loudspeaker box of claim 1, wherein the sound producing device further comprises an upper end cover and a lower end cover, the upper diaphragm clamp is arranged between the basin frame and the upper end cover, the upper end cover is provided with a first sound producing hole for the upper diaphragm to produce sound outwards, the lower diaphragm clamp is arranged between the basin frame and the lower end cover, and the lower end cover is provided with a second sound producing hole for the lower diaphragm to produce sound outwards.

10. The speaker box of claim 9, wherein the box body includes an upper bottom surface opposite to and spaced apart from the upper cover and a lower bottom surface opposite to and spaced apart from the lower cover, the upper bottom surface having a plurality of first pads supporting the upper cover, the lower bottom surface having a plurality of second pads supporting the lower cover.