JP2022015126A - Speaker - Google Patents

Abstract

To provide a speaker which can improve the drive efficiency of a diaphragm by increasing the density of magnetic flux traversing a magnetic gap, with the use of two magnets that generate repulsive magnetic fields.SOLUTION: In a speaker 1, a magnetic field generating part 10 is configured such that a second yoke 11, a second magnet 12, a middle yoke 13, a first magnet 14, and a first yoke 15 are laminated in this order in a first direction (a Y1-direction). The magnetic field generating part is also provided with an inner facing yoke 16 and an outer facing yoke 17 extending from the second yoke 11 in the first direction. In front of the inner facing yoke 16, a base member 31 and a facing magnetic body 32 are provided in a manner magnetically coupled to each other. Because the facing magnetic body 32 faces the first yoke 15 via a diaphragm 20, it is possible to increase the density of magnetic flux traversing an inner magnetic gap G1.SELECTED DRAWING: Figure 3

Description

The present invention relates to a speaker in which a magnetic field generating portion is provided with two magnets for forming a repulsive magnetic field.

In the speaker described in Patent Document 1, a magnetic circuit is fixed to a support made of aluminum, which is a non-magnetic material. The magnetic circuit is stacked in the order of a yoke, a magnet, a pole, and a repulsive magnet toward the lower part of the figure. A cylindrical portion extending from the outer peripheral portion thereof to the side of the pole is integrally formed on the yoke, and a magnetic gap is formed between the inner peripheral surface of the tubular portion of the yoke and the outer peripheral surface of the pole. The bobbin is fixed to the center of the cone-shaped diaphragm, and the voice coil wound around the bobbin is located in the magnetic gap.

In the speaker described in FIG. 2 of Patent Document 1, a support member formed of a magnetic material is fixed to the lower end of the drawing of the repulsive magnet. The support member has a shaft portion extending downward in the drawing and a flange portion protruding in the outer peripheral direction from the lower end of the shaft portion. FIG. 3 shows the distribution of magnetic flux in a magnetic circuit. In this speaker, the magnetic flux from the repulsive magnet flies to the flange portion formed on the support member, thereby reducing the leakage of the magnetic flux from the repulsive magnet.

Japanese Unexamined Patent Publication No. 2011-223165

In the speaker described in FIG. 2 of Patent Document 1, a magnetic support member is superposed on the lower end of the pole, and the support member is magnetically connected to the tubular portion of the yoke located outside the magnetic space. The clearance between the flange portion formed on the support member and the tubular portion of the yoke is long. Therefore, as shown in FIG. 2, the density of the magnetic flux from the tubular portion to the flange portion of the yoke through the magnetic void is extremely low, and the leakage of the magnetic flux from the repulsive magnet is sufficiently prevented. Not done.

The present invention solves the above-mentioned conventional problems, and can increase the density of magnetic flux emitted from two magnets provided in a magnetic field generating portion and cross a magnetic gap to improve magnetic driving efficiency. It is intended to provide a speaker.

The present invention has a diaphragm, a voice coil that applies a vibrating force to the diaphragm, and a magnetic field generating unit having a first magnet and a second magnet that apply a magnetic field to the voice coil, from the magnetic field generating unit. In the speaker in which the direction toward the diaphragm is the first direction,
The magnetic field generating part is
In the first direction, the second yoke made of magnetic material, the second magnet, the intermediate yoke made of magnetic material, the first magnet, and the first yoke made of magnetic material are stacked in this order. A facing yoke made of a magnetic material that is magnetically coupled to the second yoke and extends in the first direction to form a magnetic gap with the intermediate yoke is provided, and the voice coil is located in the magnetic gap. ,
The magnetizing surface of the second magnet facing the intermediate yoke and the magnetizing surface of the first magnet facing the intermediate yoke are magnetized on the same magnetic pole, and the magnetizing surface of the second magnet facing the second yoke. The surface and the magnetized surface of the first magnet facing the first yoke are magnetized to the same magnetic pole.
An opposed magnetic material that is magnetically coupled to the opposed yoke and extends in the first direction is provided, and the opposed magnetic material is characterized in that it faces the first yoke with the diaphragm interposed therebetween. be.

In the speaker of the present invention, the voice coil is fixed to a bobbin extending from the diaphragm, and the first space and the second space are partitioned by the diaphragm and the bobbin.
The first magnet and the second magnet are located in the first space, and the opposed magnetic material is located in the second space.

The speaker of the present invention is a phase plug in which the opposed magnetic material is located at the center of the diaphragm, and the opposed magnetic material protrudes in the first direction from the diaphragm.

Alternatively, the speaker of the present invention is a guard member in which the opposed magnetic material extends from the outer peripheral side of the diaphragm in the first direction with respect to the diaphragm.

The speaker of the present invention is provided with an opposed magnetic material that is magnetically coupled to an opposed yoke forming a magnetic gap in the magnetic field generation portion, and the opposed magnetic material faces the first yoke via a diaphragm. ing. Therefore, the magnetic flux from the first magnet located between the first yoke and the intermediate yoke can be efficiently guided into the magnetic gap, the leakage magnetic flux is reduced, and the driving efficiency of the diaphragm can be improved. can.

A perspective view showing the appearance of the speaker according to the first embodiment of the present invention. The vertical sectional view of the speaker shown in FIG. 1. An enlarged sectional view obtained by enlarging a part of the vertical sectional view shown in FIG. A perspective view showing the appearance of the speaker according to the second embodiment of the present invention. A partially enlarged cross-sectional view of the speaker shown in FIG. 4 cut along a VV line.

1 to 3 show the speaker 1 of the first embodiment of the present invention. In this speaker, two voice coils are provided on the diaphragm, and a magnetic flux that traverses each voice coil is given from one magnetic field generating portion. In the speaker 1, the Y1 direction is the first direction and the Y2 direction is the second direction. The first direction (Y1 direction) is the front of the speaker 1, the sounding direction, and the second direction (Y2 direction) is the rear.

As shown in the cross-sectional views of FIGS. 2 and 3, the speaker 1 has a case 2 made of a synthetic resin material or a non-magnetic material which is a non-magnetic metal. The case 2 is configured by combining a front case 3 located in the front (Y1 direction) in the first direction and a rear case 4 located in the rear (Y2 direction) in the second direction.

The magnetic field generating portion 10 is housed inside the front case 3. The magnetic field generating portion 10 is stacked in the order of the second yoke 11, the second magnet 12, the intermediate yoke 13, the first magnet 14, and the first yoke 15 from the rear toward the first direction (Y1 direction). The second yoke 11 is made of a magnetic material such as iron, and the planar shape seen from the front is a circle centered on the central axis O. The intermediate yoke 13 and the first yoke 15 are also made of a magnetic material such as iron, and both have uniform plate thickness dimensions in the front-rear direction (Y1-Y2), and the planar shape seen from the front. It is a ring shape (doughnut shape) centered on the central axis O.

Both the first magnet 14 and the second magnet 13 have a uniform plate thickness in the front-rear direction (Y1-Y2 direction), and the planar shape seen from the front is a ring shape (doughnut shape) centered on the central axis O. be. As shown enlarged in FIG. 3, the second magnet 12 is directed toward the intermediate yoke 13 and is joined to the intermediate yoke 13 on the front magnetized surface (first magnetized surface) 12a and the second yoke 11. It has a rear magnetized surface (second magnetized surface) 12b that is directed and joined to the second yoke 11. The first magnet 14 is joined to the front magnetized surface (first magnetized surface) 14a directed toward the first yoke 15 and joined to the first yoke 15, and joined to the intermediate yoke 13 toward the intermediate yoke 13. It has a rear magnetized surface (second magnetized surface) 14b. The front magnetizing surface 12a of the second magnet 12 and the rear magnetizing surface 14b of the first magnet 14 are magnetized to the same magnetic pole, and both are N poles. The rear magnetizing surface 12b of the second magnet 12 and the front magnetizing surface 14a of the first magnet 14 are magnetized to the same magnetic pole, and both are S poles. The north pole and the south pole may be reversed.

As shown in FIGS. 2 and 3, in the magnetic field generating portion 10, the inner facing yoke 16 is provided on the center side, and the outer facing yoke 17 is provided on the outer peripheral side. The inner facing yoke 16 has a cylindrical shape centered on the central axis O, and the outer facing yoke 17 has a cylindrical shape centered on the central axis O. The inner facing yoke 16 and the outer facing yoke 17 are magnetically coupled to the second yoke 11 and extend in the first direction (Y1 direction). Magnetic coupling as used herein refers to magnetic resistance, such as being integrally formed, being joined face-to-face with each other, or being joined via a thin adhesive layer, a thin non-magnetic material, or the like. It means that it is bonded without having or having a minute magnetic resistance. In the magnetic field generating portion 10 shown in FIGS. 2 and 3, the inner facing yoke 16 and the outer facing yoke 17 are integrally formed with the second yoke 11.

As shown enlarged in FIG. 3, the inner facing yoke 16 faces the inner peripheral surface of the intermediate yoke 13, and an inner magnetic gap G1 is formed between the inner facing yoke 16 and the intermediate yoke 13. The outer facing yoke 17 faces the outer peripheral surface of the intermediate yoke 13, and an outer magnetic gap G2 is formed between the outer facing yoke 17 and the intermediate yoke 13.

As shown in FIGS. 2 and 3, the diaphragm 20 is provided in the opening of the front case 3 facing the first direction (Y1 direction). Inside the front case 3, the magnetic field generating portion 10 and the diaphragm 20 are arranged in this order toward the first direction (Y1 direction). The curved portion 21 of the diaphragm 20 appears in the cross-sectional views of FIGS. 2 and 3. The curved portion 21 is formed of a synthetic resin material or a composite material of a paper material and a synthetic resin material. The curved portion 21 has an arc shape whose cross section is convex forward, and when viewed from the front, the curved portion 21 has a ring shape (doughnut shape) centered on the central axis O.

As shown in the cross-sectional view of FIG. 3, the outer edge member 22 is bonded to the outer periphery of the curved portion 21 as a part of the diaphragm 20, and the outer edge member 22 is adhered to the front end portion 3a of the front case 3. It is fixed. Alternatively, it is sandwiched and fixed by a plate material or the like at the front end portion 3a. As a part of the diaphragm 20, an inner edge member 23 is joined to the inner circumference of the curved portion 21. The pedestal member 31 and the opposed magnetic material 32 are sequentially stacked on the inner facing yoke 16 in the first direction, and the pedestal member 31 is formed by a fixing screw 33 inserted in the center of the inner facing yoke 16. And the opposing magnetic material 32 are fixed. The inner edge member 23 is sandwiched and fixed between the pedestal member 31 and the opposed magnetic body 32.

The outer edge member 22 and the inner edge member 23 have lower rigidity than the curved portion 21, and are easily deformed by bending. In the diaphragm 20, the curved portion 21 can vibrate in the front-rear direction (Y1-Y2 direction) by deforming the outer edge member 22 and the inner edge member 23.

The pedestal member 31 and the opposed magnetic material 32 are made of a magnetic material such as iron. The pedestal member 31 is magnetically coupled to the inner facing yoke 16, and the facing magnetic body 32 is magnetically coupled to both the pedestal member 31 and the inner facing yoke 16. That is, the inner facing yoke 16 and the pedestal member 31 are fixed by the tightening force of the fixing screw 33 in a state of being in contact with each other. The pedestal member 31 and the opposed magnetic body 32 are fixed by the tightening force of the fixing screw 33 with a minute gap between the inner edge member 23 which is a part of the diaphragm 20.

The opposing magnetic body 32 is located at the center of the diaphragm 20 and projects so as to have a gradually narrowing diameter toward the front (Y1 direction), which is the first direction. The opposed magnetic body 32 having this shape is called an equalizer or a phase plug, and spreads the directivity of the sound emitted in the first direction by the vibration of the diaphragm 20, and particularly the directivity of the sound pressure in the high frequency range. Is controlled to spread toward the first direction (Y1 direction).

As shown in FIG. 3, the inner bobbin 24 extends in the second direction (Y2 direction) from the joint portion between the curved portion 21 of the diaphragm 20 and the inner edge member 23, and is behind the inner bobbin 24. The inner voice coil 25 is fixed to the end. The inner bobbin 24 and the inner voice coil 25 have a cylindrical shape located on the outer periphery of the inner facing yoke 16, and the inner voice coil 25 is located inside the inner magnetic gap G1. The outer bobbin 26 extends in the second direction (Y2 direction) from the joint between the curved portion 21 of the diaphragm 20 and the outer edge member 22, and the outer voice coil 27 extends to the rear end of the outer bobbin 26. It is fixed. The outer bobbin 26 and the outer voice coil 27 have a cylindrical shape located on the outer periphery of the intermediate yoke 13 and the first magnet 14, and the outer voice coil 27 is located inside the outer magnetic gap G2.

As shown in FIGS. 2 and 3, the front of the front case 3 is covered with the guard member 5. The guard member 5 is made of a magnetic material and is surface-plated with a porous steel plate or a net-like steel plate. Alternatively, the surface of a porous or net-like synthetic resin material is metal-plated. Alternatively, it may be formed of an aluminum alloy or the like. The guard member 5 is formed in a gently inclined conical shape, and is arranged at intervals in front of the diaphragm 20 and the opposing magnetic body 32.

Next, the sounding operation of the speaker 1 will be described.
FIG. 3 shows the main paths of the first magnetic flux Φ1, the second magnetic flux Φ2, the third magnetic flux Φ3, and the fourth magnetic flux Φ4. The magnetic field generation unit 10 utilizes a repulsive magnetic field, and the first magnetic flux Φ1 and the second magnetic flux Φ2 cross the inner magnetic gap G1 through a path that repels each other. The third magnetic flux Φ3 and the fourth magnetic flux Φ4 cross the outer magnetic gap G2 through a path that repels each other. Each magnetic flux Φ1, Φ2, Φ3, Φ4 is actually a bundle of magnetic fields having a predetermined magnetic flux density, but for convenience of explanation, in FIG. 3, the main paths of the magnetic fluxes Φ1, Φ2, Φ3, Φ4 are shown. Each is indicated by a single dashed line.

The second magnetic flux Φ2 generated by the second magnet 12 crosses the inner magnetic gap G1 from the front magnetizing surface 12a of the second magnet 12 via the intermediate yoke 13, and obtains the second yoke 11 from the inner facing yoke 16. It reaches the rear magnetizing surface 12b of the second magnet 12. The fourth magnetic flux Φ4 crosses the outer magnetic gap G2 from the front magnetizing surface 12a of the second magnet 12 via the intermediate yoke 13, obtains the second yoke 11 from the outer facing yoke 17, and is magnetized backward of the second magnet 12. It reaches the surface 12b. The inner facing yoke 16 forming the inner magnetic gap G1 is integrated with the second yoke 11, and the outer facing yoke 17 forming the outer magnetic gap G2 is integrated with the second yoke 11. Therefore, the magnetic flux density of the second magnetic flux Φ2 that crosses the inner magnetic gap G1 and the magnetic flux density of the third magnetic flux Φ3 that crosses the outer magnetic gap G2 are structurally high.

On the other hand, regarding the first magnet 14, the diaphragm 20 is located in the front (Y1 direction) opposite to the intermediate yoke 13, and the bobbins 24 and 26 extend from the diaphragm 20 into the magnetic gaps G1 and G2. There is. Therefore, the outer facing yoke and the inner facing yoke cannot be extended from the first yoke 15 toward the second direction (Y2 direction), and between the outer facing yoke and the intermediate yoke 13 and the inner facing yoke thereof. A magnetic gap cannot be formed with the intermediate yoke 13. In other words, the inner facing yoke 16 and the outer facing yoke 17 shown in FIG. 3 and the first yoke 15 cannot be magnetically coupled to each other.

Therefore, the third magnetic flux Φ3 crosses the outer magnetic gap G2 from the rear magnetizing surface 14b of the first magnet 14 through the intermediate yoke 13 to reach the outer facing yoke 17, but then passes through the space to reach the first yoke 15. Will return to. On the right side of the drawing of the first magnet 14, there is a front end portion of the non-magnetic front case 3 and a part of the non-magnetic guard member 5, but the magnetic member does not face each other. As a result, the magnetic flux density of the third magnetic flux Φ3 that emerges from the first magnet 14 and crosses the outer magnetic gap G2 becomes very low.

As shown in FIG. 3, in the central portion of the speaker 1, the first space (A) and the second space (B) are partitioned by the curved portion 21 of the diaphragm 20 and the inner bobbin 24, and the second space (B) is divided. The intermediate yoke 13, the first magnet 14, and the first yoke 15 are located in one space (A), and the pedestal member 31 and the opposing magnetic body 32 are located in the second space (B). Since the opposing magnetic body 32 faces the first yoke 15 via the diaphragm 20, the spatial distance between the opposed magnetic body 32 and the first yoke 15 is extremely short. Further, both the opposed magnetic body 32 and the pedestal member 31 are formed of a magnetic material and are magnetically coupled to the inner opposed yoke 16. Therefore, the magnetic flux density of the first magnetic flux Φ1 crossing the inner magnetic gap G1 is significantly higher than the magnetic flux density of the third magnetic flux Φ3 crossing the outer magnetic gap G2.

The voice current flowing through the inner voice coil 25 and the magnetic flux crossing the inner magnetic gap G1 apply vibration to the diaphragm 20 from the inner bobbin 24, and the voice current flowing through the outer voice coil 27 and the outer magnetic gap G2 are crossed. Vibration is applied to the diaphragm 20 from the outer bobbin 26 by the magnetic current generated. Then, the vibration of the diaphragm 20 generates a sound pressure toward the front (Y1 direction), which is the first direction.

As shown in FIG. 3, since the magnetic flux density of the first magnetic flux Φ1 crossing the inner magnetic gap G1 is higher than the magnetic flux density of the third magnetic flux Φ3 crossing the outer magnetic gap G2, the inner bobbin from the inner voice coil 25 The vibration energy given to the vibrating plate 20 via 24 becomes large. Therefore, the sound pressure can be increased and the reproduced sound quality is also good. Further, by efficiently circulating the first magnetic flux Φ1 generated by the first magnet 14, the heat generation of the first magnet 14 can be suppressed, and the demagnetization of the first magnet 14 can also be suppressed.

The speaker 1 shown in FIGS. 1 to 3 is a system in which the diaphragm 20 is driven by two voice coils 25 and 27. Since the density of the magnetic flux across the inner voice coil 25 is higher than the density of the magnetic flux across the outer voice coil 27, the vibration energy per unit circumference acting on the inner voice coil 25 acts on the outer voice coil 27. It is larger than the vibration energy per unit circumference. However, since the inner voice coil 25 has a smaller diameter and a shorter circumference, and the outer voice coil 27 has a larger diameter and a longer circumference than the inner voice coil 25, the vibration energy obtained on the entire circumference of the inner voice coil 25 and the outer side are obtained. The difference in vibration energy obtained around the entire circumference of the voice coil 27 can be reduced, and the diaphragm 20 can be driven in a well-balanced manner by the two voice coils 25 and 27.

Since the opposing magnetic body 32 facing the first yoke 15 with the diaphragm 20 sandwiched therein functions as an equalizer or a phase plug, it is not necessary to provide a special member different from the conventional one as the opposed magnetic body 32.

4 and 5 show the speaker 101 of the second embodiment of the present invention. This speaker 101 is used as a tweeter, and only one voice coil is provided. The speaker 101 is different in the shape of the member from the speaker 1 of the first embodiment shown in FIGS. 1 to 3, but the members having the same function are designated by the same reference numerals and the first embodiment is used. The explanation that overlaps with is omitted as much as possible.

Also in the speaker 101 shown in FIGS. 4 and 5, the magnetic field generating unit 10 and the diaphragm 20 are arranged in order toward the front (Y1 direction), which is the first direction. The magnetic field generating portion 10 is laminated in the order of the second yoke 11, the second magnet 12, the intermediate yoke 13, the first magnet 14, and the first yoke 15 from the rear to the front, that is, from the first direction (Y1 direction). There is. Each of these members has a disk shape when viewed from the front. The outer facing yoke 17 extends from the outer peripheral portion of the second yoke 11 toward the first direction (Y1 direction). The outer facing yoke 17 is magnetically coupled to the second yoke 11. That is, the outer facing yoke 17 is integrally formed with the second yoke 11. The outer facing yoke 17 has a cylindrical shape, and a magnetic gap G is formed between the outer peripheral surface of the intermediate yoke 13 and the inner peripheral surface of the outer facing yoke 17.

The pedestal member 31 and the opposing magnetic body 32 are laminated in order on the outer facing yoke 17 in the first direction (Y1-Y2 direction) and fixed to each other by means such as adhesion or screwing. The pedestal member 31 and the opposed magnetic material 32 are made of a magnetic material such as iron. The outer facing yoke 17, the pedestal member 31, and the facing magnetic body 32 are magnetically coupled to each other.

The diaphragm 20 has a dome-shaped curved portion 21 and an edge member 22 connected to the outer periphery of the curved portion 21, and the edge member 22 is sandwiched between the pedestal member 31 and the opposed magnetic body 32. It is fixed. An outer bobbin 26 extending in the second direction (Y2 direction) is fixed to the joint boundary portion between the curved portion 21 and the edge member 22. A cylindrical outer voice coil 27 fixed to the rear end of the outer bobbin 26 is located inside the magnetic gap G.

As shown in FIG. 4, the opposed magnetic bodies 32 are provided at a plurality of locations (three locations) so as to extend from the outer peripheral portion of the diaphragm 20 to the front of the curved portion 21. The facing magnetic body 32 is a guard member, and the presence of the facing magnetic body 32 can prevent the diaphragm 20 from being damaged by a finger or the like.

As shown in FIG. 5, the speaker 101 is divided into an inner first space (A) and an outer second space (B) by a diaphragm 20 and an outer bobbin 26. The intermediate yoke 13, the first magnet 14, and the first yoke 15 are arranged in the first space (A), and the pedestal member 31 and the opposing magnetic body 32 are arranged in the second space (B). The first yoke 15 is formed with protruding portions 15a projecting forward toward the curved portion 21 of the diaphragm 20 at a plurality of locations (three locations), and each of the opposing magnetic bodies 32 is formed on the diaphragm 20. It faces the protruding portion 15a of the first yoke 15 at a short distance via the curved portion 21.

FIG. 5 shows the main path of the magnetic flux Φ6 generated by the second magnet 12 and the main path of the magnetic flux Φ5 formed by the first magnet 14. Also in this speaker 101, the magnetic flux Φ5 generated by the first magnet 14 crosses the magnetic gap G via the intermediate yoke 13, reaches the facing magnetic body 32 from the outer facing yoke 17 via the pedestal member 31, and further faces. It flies to the projecting portion 15a facing the magnetic body 32 at a short distance and returns from the first yoke 15 to the first magnet 14. Therefore, the magnetic flux density of the magnetic flux Φ5 that becomes a repulsive magnetic field and crosses the magnetic gap G can be increased.

1 Speaker 2 Case 10 Magnetic field generator 11 2nd yoke 12 2nd magnet 13 Intermediate yoke 14 1st magnet 15 1st yoke 16 Inner facing yoke 17 Outer facing yoke 20 Vibrating plate 21 Curved part 22 Outer edge member 23 Inner edge member 24 Inner bobbin 25 Inner voice coil 26 Outer bobbin 27 Outer voice coil 31 Pedestal member 32 Opposed magnetic material (A) First space (B) Second space G1 Inner magnetic gap G2 Outer magnetic gap G Magnetic gap

Claims (4)

It has a diaphragm, a voice coil that applies a vibrating force to the diaphragm, and a magnetic field generating portion having a first magnet and a second magnet that apply a magnetic field to the voice coil, and the magnetic field generating portion is transferred to the diaphragm. In a speaker whose direction is the first direction,
The magnetic field generating part is
In the first direction, the second yoke made of magnetic material, the second magnet, the intermediate yoke made of magnetic material, the first magnet, and the first yoke made of magnetic material are stacked in this order. A facing yoke made of a magnetic material that is magnetically coupled to the second yoke and extends in the first direction to form a magnetic gap with the intermediate yoke is provided, and the voice coil is located in the magnetic gap. ,
The magnetizing surface of the second magnet facing the intermediate yoke and the magnetizing surface of the first magnet facing the intermediate yoke are magnetized on the same magnetic pole, and the magnetizing surface of the second magnet facing the second yoke. The surface and the magnetized surface of the first magnet facing the first yoke are magnetized to the same magnetic pole.
A speaker characterized in that an opposed magnetic material that is magnetically coupled to the opposed yoke and extends in the first direction is provided, and the opposed magnetic material faces the first yoke with the diaphragm interposed therebetween. The voice coil is fixed to the bobbin extending from the diaphragm, and the first space and the second space are separated by the diaphragm and the bobbin.
The speaker according to claim 1, wherein the first magnet and the second magnet are located in the first space, and the opposed magnetic material is located in the second space. The speaker according to claim 1 or 2, wherein the opposed magnetic material is located at the center of the diaphragm, and the opposed magnetic material is a phase plug that protrudes in the first direction from the diaphragm. The speaker according to claim 1 or 2, wherein the opposed magnetic material is a guard member extending from the outer peripheral side of the diaphragm in a first direction with respect to the diaphragm.

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