Speaker device and acoustic system
By using the first and second speakers in the speaker equipment and arranging their sound surfaces on the boundary of the speaker cabinet, the problems of space limitations and vibration are solved, and the heavy production of low-frequency sounds and the improvement of sound clarity are achieved.
Patent Information
- Application Number
- JP2024224410
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2025-03-18
- Estimated Expiration
- 2040-09-28
AI Technical Summary
In the case of limited space, it is difficult to install large speaker enclosure to achieve low-frequency sound reproduction, while the speaker equipment cannot firmly adhere to other objects, causing energy to be converted into vibration rather than sound.
A speaker device consisting of the first and second speakers is adopted, wherein the first speaker has an acoustic surface communicating with the room, the second speaker has an acoustic surface not communicating with the room, and a closed space is formed through a cabinet body, the acoustic surface of the second speaker is supplied to the first speaker, and the acoustic surface of both is arranged on the boundary of the cabinet body, and the acoustic surface of the first speaker faces the closed space.
Reproduction of low-frequency sounds with limited space is achieved and vibration of speaker equipment is suppressed to ensure that energy is converted into clear sound.
Smart Images
Figure 2025038184000001_ABST
Abstract
Description
[Technical field]
[0001] The present disclosure relates to a speaker device and an audio system. [Background technology]
[0002] In a speaker device, there is a technology in which the back surface of a speaker faces the outside of a vehicle to form an infinite baffle (see, for example, Patent Document 1). In a speaker device equipped with a main speaker and an auxiliary speaker, there is a technology in which the sound emitting surface of the auxiliary speaker faces the back surface of the main speaker (see, for example, Patent Documents 2 and 3). [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Patent No. 5988874 specification [Patent Document 2] Japanese Patent Application Publication No. 9-74599 [Patent Document 3] Patent No. 4079827 specification Summary of the Invention [Problem to be solved by the invention]
[0004] A speaker device needs a large enclosure to reproduce low-pitched sounds. However, in some cases, such as when the installation space for the speaker device is limited, it is not possible to install a large enclosure.
[0005] Furthermore, if the speaker device cannot be firmly attached to another object, the regenerated energy will be converted into vibration instead of sound. Furthermore, if the installation location of the speaker device is complicated or if the speaker device is required to be lightweight, the enclosure may need to be made thinner. In this case, it becomes difficult to attach the enclosure to another object.
[0006] The present disclosure provides a speaker device and an audio system that are capable of reproducing low-pitched sounds while suppressing vibrations of the speaker device. [Means for solving the problem]
[0007] A speaker device of a first aspect of the present disclosure comprises a first speaker having a first surface communicating with the interior of a room and a second surface not communicating with the interior of the room, a second speaker having a first surface communicating with the exterior of the room and a second surface not communicating with the exterior of the room, and a cabinet in which a closed space is formed by a surface forming a boundary, wherein the second surface of the first speaker is a rear surface and the second surface of the second speaker is a rear surface, a sound signal is supplied to the first speaker, and the second surface of the first speaker and the second surface of the second speaker are disposed at the boundary facing the closed space. A speaker device of a second aspect of the present disclosure includes a first speaker having a first surface communicating with the interior of the vehicle cabin and a second surface not communicating with the interior of the vehicle cabin, a second speaker having a first surface communicating with the outside of the vehicle and a second surface not communicating with the outside of the vehicle, and a cabinet having a surface forming a boundary where a closed space is formed, wherein the second surface of the first speaker is a sound emitting surface and the second surface of the second speaker is a sound emitting surface, a sound signal is supplied to the first speaker, and the second surface of the first speaker and the second surface of the second speaker are arranged at the boundary facing the closed space. A speaker device of a third aspect of the present disclosure comprises a first speaker having a first surface communicating with the interior of the vehicle cabin and a second surface not communicating with the interior of the vehicle cabin, a second speaker having a first surface communicating with the outside of the vehicle and a second surface not communicating with the outside of the vehicle, and a cabinet in which a closed space is formed by a surface forming a boundary, wherein the second surface of the first speaker is a rear surface and the second surface of the second speaker is a sound emitting surface, a sound signal is supplied to the first speaker, and the second surface of the first speaker and the second surface of the second speaker are disposed at the boundary facing the closed space. A fourth aspect of the speaker device of the present disclosure comprises a first speaker having a first surface communicating with the interior of the vehicle cabin and a second surface not communicating with the interior of the vehicle cabin, a second speaker having a first surface communicating with the outside of the vehicle and a second surface not communicating with the outside of the vehicle, and a cabinet having a surface forming a boundary that forms a closed space, wherein the second surface of the first speaker is a sound emitting surface and the second surface of the second speaker is a rear surface, a sound signal is supplied to the first speaker, and the second surface of the first speaker and the second surface of the second speaker are disposed at the boundary facing the closed space.
[0008] The acoustic system of the present disclosure includes a speaker device according to any one of the above-described aspects, and a phase control unit that generates a first sound signal and a second sound signal, which are two sound signals having a phase difference, supplies the first sound signal to the first speaker, and supplies the second sound signal to the second speaker. [Brief description of the drawings]
[0009] [Figure 1] 1 is a sectional view of the speaker device according to the first embodiment. [Diagram 2] 1 is a side view of the speaker device according to the first embodiment. [Diagram 3] 1 is a front view of the speaker device according to the first embodiment. [Figure 4] FIG. 2 is a view taken along line AA in FIG. [Diagram 5] 1 is a block diagram of an audio system according to a first embodiment. [Figure 6] FIG. 11 is a sectional view of a speaker device according to a second embodiment. [Figure 7] FIG. 11 is a side view of the speaker device according to the second embodiment. [Figure 8] FIG. 11 is a block diagram of an audio system according to a second embodiment. [Figure 9] FIG. 11 is a cross-sectional view of a speaker device according to a third embodiment. [Figure 10] FIG. 11 is a side view of the speaker device according to the third embodiment. [Figure 11] FIG. 11 is a cross-sectional view of a speaker device according to a fourth embodiment. [Figure 12] FIG. 13 is a sectional view of a speaker device according to a fifth embodiment. [Figure 13] FIG. 13 is a cross-sectional view of a speaker device according to a sixth embodiment. [Figure 14] FIG. 13 is a side view of the speaker device according to the sixth embodiment. [Figure 15] 14 is a view taken along line BB in FIG. 13. [Figure 16] FIG. 13 is a front view of the speaker device according to the seventh embodiment. [Figure 17] 17 is a view taken along the line CC in FIG. 16. [Figure 18] FIG. 17 is a view taken along line DD in FIG. [Figure 19] FIG. 2 is a schematic diagram showing a model of a first speaker. [Figure 20] 20 is a graph showing sound distortion in the model of the first speaker shown in FIG. 19. [Figure 21] FIG. 2 is a schematic diagram showing a model of a speaker apparatus including a first speaker and a second speaker arranged in the same direction. [Figure 22] 22 is a graph showing sound distortion in the model of the speaker device shown in FIG. 21. [Diagram 23] FIG. 2 is a schematic diagram showing a model of a speaker device including a first speaker and a second speaker arranged in opposite directions. [Figure 24] 24 is a graph showing sound distortion in the model of the speaker device shown in FIG. 23. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Note that the dimensions and scale of each part in the drawings are appropriately different from the actual ones. In addition, the embodiment described below is a preferred specific example of the present invention. Therefore, various technically preferable limitations are attached to this embodiment. However, the scope of the present disclosure is not limited to these forms unless otherwise specified in the following description to limit the present disclosure.
[0011] FIG. 1 is a cross-sectional view of the speaker device 1A according to the first embodiment. FIG. 2 is a side view of the speaker device 1A. FIG. 3 is a front view of the speaker device 1A. FIG. 4 is a view taken along the line AA in FIG. 1. The speaker device 1A shown in FIGS. 1 to 4 can be used, for example, as an in-vehicle speaker device mounted on a vehicle such as an automobile. The speaker device 1A may be attached to a door of the vehicle via a door trim, for example. Note that the use of the speaker device 1A is not limited to in-vehicle use, and may be for other uses.
[0012] The speaker device 1A includes a first speaker 10A and a second speaker 20A. In FIG. 1, a part of the speaker device 1A is shown in cross section. This cross section is obtained by cutting the speaker device 1A along a plane including an axis Z1 of the first speaker 10A and an axis Z2 of the second speaker 20A. The axis Z1 is a line segment that is parallel to the vibration direction of a diaphragm 2 described later and passes through the center of the diaphragm 2. The axis Z1 direction is the direction in which the axis Z1 extends.
[0013] In the description of the first speaker 10A, in the direction of the axis Z1, the side on which the diaphragm 2 is arranged is the front side, and the opposite side is the rear side. Of the two surfaces spaced apart in the direction of the axis Z1, the surface on which the diaphragm 2 is arranged is the sound emitting surface, and the opposite surface is the rear. The same is true for the axis Z2. Moreover, the three directions perpendicular to each other are the X direction, the Y direction, and the Z direction. The Z direction is parallel to the direction of the axis Z1.
[0014] In the description of the cabinet 30A described later, the right side in the drawing is the front side, and the left side in the drawing is the rear side. Note that in other embodiments described later, the front side and rear side of the cabinet and the front side and rear side of the first speaker or the front side and rear side of the second speaker may not be on the same side.
[0015] The first speaker 10A and the second speaker 20A have the same configuration, but the first speaker 10A and the second speaker 20A may have different configurations. The first speaker 10A has a diaphragm 2, a drive unit 3, and a speaker frame 4. The second speaker 20A has a diaphragm 2, a drive unit 3, and a speaker frame 4. The axis Z1 and the axis Z2 are coaxial.
[0016] The diaphragm 2 is a vibrating body made of a sheet material that emits sound by vibration. The sheet material is obtained, for example, by impregnating a fiber base material with a resin material and then curing or solidifying the resin material. Examples of the resin material include acrylic resin, polyurethane, melamine resin, modified rubber resin, and phenolic resin. Examples of the fiber base material include carbon fiber, aramid fiber, glass fiber, ceramic fiber, silica fiber, metal fiber, potassium titanate fiber, zirconia fiber, polyacrylate fiber, polyphenylene sulfide fiber, vinylon fiber, rayon fiber, nylon fiber, polyester fiber, acrylic fiber, polypropylene fiber, polyethylene fiber, cotton fiber, hemp fiber, and cellulose fiber.
[0017] The diaphragm 2 vibrates in a direction along the axis Z1 or the axis Z2. The diaphragm 2 is cone-shaped. Note that the shape of the diaphragm 2 is not limited to a cone shape, and may be, for example, a dome shape.
[0018] The driving unit 3 is a mechanism that drives the diaphragm 2 based on an input electric signal. The driving unit 3 includes a magnetic circuit that generates a magnetic field, and a voice coil connected to the diaphragm 2. The magnetic circuit includes a magnet and a yoke. When an electric signal is input, the voice coil vibrates the diaphragm 2 due to the interaction of magnetic forces between the voice coil and the magnet. This vibration causes the diaphragm 2 to emit a sound based on the electric signal. Note that the driving unit 3 is not limited to a configuration having a voice coil and a magnet, and may be any configuration as long as it is capable of driving the diaphragm 2 based on an electric signal.
[0019] The first speaker 10A has a first surface 11 communicating with the room J1 and a second surface 12 not communicating with the room J1. The second speaker 20A has a first surface 21 communicating with the outside J2 and a second surface 22 not communicating with the outside J2. "Communicating with the room J1" means that the speaker is in contact with the space of the room J1 and is not in contact with the internal space of the cabinet 30A described later. "Not in contact with the room J1" means that the speaker is in contact with the internal space of the cabinet 30A and is not in contact with the space of the room J1. "Communicating with the outside J2" means that the speaker is in contact with the space of the outside J2 and is not in contact with the internal space of the cabinet 30A. "Not in contact with the outside J2" means that the speaker is in contact with the internal space of the cabinet 30A and is not in contact with the space of the outside J2.
[0020] When the speaker device 1A is mounted in an automobile, the interior J1 is the interior of the automobile, and the exterior J2 is the outside of the automobile. When the speaker device 1A is installed in the door of an automobile, even if the first surface 11 of the first speaker 10A faces the outside of the automobile when the door is opened, when the first surface 11 faces the interior of the automobile when the door is closed, the first surface 11 faces the interior of the automobile. When the first surface 21 of the second speaker 20A faces a space in an opening communicating with the outside of the automobile, the first surface 21 communicates with the exterior of the automobile J2. The interior of the automobile is the interior of the automobile even if it communicates with the outside of the automobile when the door or window is open.
[0021] The first surface 11 of the first speaker 10A is a sound emitting surface, and the second surface 12 is a rear surface. The first surface 21 of the second speaker 20A is a sound emitting surface, and the second surface 22 is a rear surface. The sound emitting surface of the first speaker 10A communicates with the room J1, and the sound emitting surface of the second speaker 20A communicates with the room J2.
[0022] The speaker device 1A includes a cabinet 30A that holds the first speaker 10A and the second speaker 20A. The cabinet 30A is box-shaped and holds the first speaker 10A and the second speaker 20A. The cabinet 30A includes a front plate 31A, a back plate 32A, a side plate 33A, a side plate 34A, a side plate 35A, and a side plate 36A. The front plate 31A and the back plate 32A face each other in the Z direction. The side plate 33A and the side plate 34A face each other in the X direction. The side plate 35A and the side plate 36A face each other in the Y direction. An opening 37A is formed in the side plate 33A. The opening 37A is formed in the center of the side plate 33A in the Z direction.
[0023] The cabinet 30A forms a closed space with a surface that forms a boundary. The surfaces that form the boundary include a front plate 31A, a back plate 32A, a side plate 33A, a side plate 34A, a side plate 35A, and a side plate 36A. The surfaces that form the boundary include a back plate 42A of the first cabinet 40A and a front plate 51A of the second cabinet 50A, which will be described later. The surfaces that form the boundary include an inner wall plate 71A, an inner wall plate 72A, and an inner wall plate 73A of the connecting portion 60A, which will be described later. The cabinet 30A forms a closed space, which is a closed internal space, in a state in which the first speaker 10A and the second speaker 20A are held. Forming a closed space with a surface that forms a boundary includes forming a closed internal space in a state in which the first speaker 10A and the second speaker 20A are held.
[0024] The second surface 12 of the first speaker 10A and the second surface 22 of the second speaker 20A are disposed at the boundary of the cabinet 30A facing the closed space side. "The second surfaces 12 and 22 are disposed at the boundary of the cabinet 30A facing the closed space side" includes "the second surfaces 12 and 22 are disposed so as to be in contact with the internal space of the cabinet 30A."
[0025] The cabinet 30A is provided with a mounting piece 8. The mounting piece 8 protrudes outward from side panels 33A to 36A of the cabinet 30A. The speaker device 1A is attached to another member via the mounting piece 8. Outside the speaker device 1A, the front side of the mounting piece 8 is the indoor side J1, and the rear side of the mounting piece 8 is the outdoor side J2. The mounting piece 8 may be a flange, a channel, or the like.
[0026] The cabinet 30A includes a first cabinet 40A, a second cabinet 50A, and a connecting portion 60A. The connecting portion 60A is disposed between the first cabinet 40A and the second cabinet 50A in the Z direction. The connecting portion 60A communicates between the first cabinet 40A and the second cabinet 50A.
[0027] The first cabinet 40A holds the first speaker 10A. The first cabinet 40A includes a front panel 31A and a rear panel 42A that face each other in the Z direction. The first cabinet 40A includes a first portion 43A of the side panel 33A, a first portion 44A of the side panel 34A, a first portion 45A of the side panel 35A, and a first portion 46A of the side panel 36A.
[0028] An opening 38A for holding the first speaker 10A is formed in the front panel 31A. A speaker frame 4 of the first speaker 10A is fixed to the periphery of the opening 38A. The diaphragm 2 and driving section 3 of the first speaker 10A are housed in a first cabinet 40A.
[0029] The first portion 43A of the side plate 33A and the first portion 44A of the side plate 34A face each other in the X direction. The first portion 45A of the side plate 35A and the first portion 46A of the side plate 36A face each other in the Y direction. In the X direction, an opening 47A is formed between the back plate 42A and the side plate 34A.
[0030] The second cabinet 50A holds the second speaker 20A. The second cabinet 50A includes a front panel 51A and a rear panel 32A that face each other in the Z direction. The second cabinet 50A includes a second portion 53A of the side panel 33A, a second portion 54A of the side panel 34A, a second portion 55A of the side panel 35A, and a second portion 56A of the side panel 36A.
[0031] An opening 57A for holding the second speaker 20A is formed in the front plate 51A. The speaker frame 4 of the second speaker 20A is fixed to the periphery of the opening 57A. The diaphragm 2 and driving section 3 of the second speaker 20A are housed in the second cabinet 50A.
[0032] The second portion 53A of the side plate 33A and the second portion 54A of the side plate 34A face each other in the X direction. The second portion 55A of the side plate 35A and the second portion 56A of the side plate 36A face each other in the Y direction. In the X direction, an opening 58A is formed between the front plate 51A and the side plate 34A.
[0033] The connecting portion 60A includes an inner wall plate 71A and a third portion 64A of the side plate 34A facing each other in the X direction. The internal space of the connecting portion 60A communicates with the internal space of the first cabinet 40A and the internal space of the second cabinet 50A through the opening 47A and the opening 58A.
[0034] The internal space of the cabinet 30A includes the internal space of the first cabinet 40A, the internal space of the second cabinet 50A, and the internal space of the connecting portion 60A. The internal space of the cabinet 30A is a closed space and is not communicated with the indoor space J1 and the outdoor space J2. The second surface 12, which is the rear surface of the first speaker 10A, and the second surface 22, which is the rear surface of the second speaker 20A, are in contact with the internal space of the cabinet 30A.
[0035] An open space J3 communicating with the outside J2 is formed on the front side of the second speaker 20A. The open space J3 communicates with the outside J2 through an opening 37A. The open space J3 includes a space formed between the rear plate 42A of the first cabinet 40A and the front plate 51A of the second cabinet 50A in the Z direction.
[0036] 4, the open space J3 is separated from the internal space of the cabinet 30A by inner wall plates 71A, 72A, and 73A. The inner wall plates 72A and 73A are disposed outside the second speaker 20A in the Y direction. The inner wall plate 72A faces the side plate 35A in the Y direction. The inner wall plate 73A faces the side plate 36A in the Y direction.
[0037] Next, an acoustic system 86A according to a first embodiment will be described with reference to Fig. 5. Fig. 5 is a block diagram of the acoustic system 86A. The acoustic system 86A includes a speaker device 1A and a phase control device 80A. The phase control device 80A includes a control unit 81. The control unit 81 controls an electric signal S1 and an electric signal S2 outputted to the first speaker 10A and the second speaker 20A. The control unit 81 includes a processing circuit 82 such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array) and a storage circuit 83 such as a semiconductor memory.
[0038] The memory circuit 83 stores a control program and various parameters used for controlling the phase of the electric signal. The memory circuit 83 also functions as a working area for the processing circuit 82. The processing circuit 82 reads out the control program from the memory circuit 83. The processing circuit 82 executes the read control program to function as a control center of the speaker device 1A. The control unit 81 outputs an electric signal S1 to the first speaker 10A and outputs an electric signal S2 to the second speaker 20A.
[0039] The processing circuit 82 functions as a phase control unit 85A that controls the phase of the electric signal S1 output to the first speaker 10A and the electric signal S2 output to the second speaker 20A. The processing circuit 82 includes a delay circuit 84. The phase control unit 85A generates a first sound signal and a second sound signal, which are two sound signals having a phase difference. The first sound signal is the electric signal S1. The second sound signal is the electric signal S2.
[0040] The processing circuit 82 generates an electric signal S1 and an electric signal S2 that are in opposite phase to each other. As a result, the diaphragm 2 of the first speaker 10A and the diaphragm 2 of the second speaker 20A vibrate in opposite directions to each other. Here, "vibrating in opposite directions" means that when the diaphragm 2 of the second speaker 20A moves to the front side, the diaphragm 2 of the first speaker 10A moves to the rear side, and when the diaphragm 2 of the second speaker 20A moves to the rear side, the diaphragm 2 of the first speaker 10A moves to the front side.
[0041] For example, when the diaphragm 2 of the second speaker 20A moves to the rear side, the diaphragm 2 of the first speaker 10A moves to the front side. When the diaphragm 2 of the second speaker 20A moves to the rear side, vibration is transmitted inside the cabinet 30A. In the cabinet 30A, the vibration is transmitted in the order of the internal space of the second cabinet 50A, the internal space of the connecting part 60A, and the internal space of the first cabinet 40A. In this way, when the vibration of the diaphragm 2 of the second speaker 20A moves to the rear side, the vibration is transmitted to the diaphragm 2 of the first speaker 10A in the internal space of the first cabinet 40A so as to push the diaphragm 2 from the rear side to the front side. The phase control unit 85 controls the phase of the electric signal S1 so that the diaphragm 2 of the first speaker 10A moves from the rear side to the front side, so that the air density is suppressed in the internal space of the cabinet 30A. Suppressing the air density means suppressing the pressure change inside the cabinet 30A.
[0042] Similarly, for example, when the diaphragm 2 of the second speaker 20A moves to the front side, the diaphragm 2 of the first speaker 10A moves to the rear side. When the diaphragm 2 of the second speaker 20A moves to the front side, vibration is transmitted inside the cabinet 30A. In the cabinet 30A, the vibration is transmitted in the order of the internal space of the second cabinet 50A, the internal space of the connecting part 60A, and the internal space of the first cabinet 40A. In this way, when the vibration of the diaphragm 2 of the second speaker 20A moves to the front side, the vibration is transmitted to the diaphragm 2 of the first speaker 10A in the internal space of the first cabinet 40A so as to pull the diaphragm 2 from the rear side. The phase control unit 85 controls the phase of the electric signal S1 so that the diaphragm 2 of the first speaker 10A moves from the front side to the rear side, so that the air density is suppressed in the internal space of the cabinet 30A.
[0043] As described above, the direction in which the diaphragm 2 of the first speaker 10A is displaced is opposite to the direction in which the diaphragm 2 of the second speaker 20A is displaced. Therefore, the phase of the electric signal S1 and the phase of the electric signal S2 are in an opposite phase relationship. However, in the cabinet 30A, the vibration of the second speaker 20A is transmitted to the first speaker 10A via the air in the internal space. Therefore, it takes time for the vibration of the second speaker 20A to be transmitted to the first speaker 10A.
[0044] The delay circuit 84 can delay the electric signal S1 with respect to the electric signal S2. The delay circuit 84 delays the electric signal S1 with respect to the electric signal S2 according to the transmission path of the vibration from the second speaker 20A to the first speaker 10A. The transmission path of the vibration here refers to the transmission path of the vibration through the air inside the cabinet 30A. The delay circuit 84 delays the electric signal S1 so that the first speaker 10A vibrates in the same manner at the timing when the vibration of the second speaker 20A is transmitted to the first speaker 10A through the air inside the cabinet 30A. The phase control unit 85A controls the phase of the electric signal S1 and the electric signal S2 so that the phase of the vibration transmitted from the second speaker 20A to the first speaker 10A and the phase of the displacement of the diaphragm 2 due to the electric signal S1 input to the first speaker 10A are in opposite phases. Note that when the vibration transmitted through the transmission path is small, the delay circuit 84 may be omitted. Furthermore, when the volume of the cabinet 30A is small and the transmission path is short, a phase difference is unlikely to occur, so the delay circuit 84 may be omitted. In particular, when the resonance frequency of the cabinet 30A is low (several tens to several hundreds of Hz), the delay circuit 84 can be omitted.
[0045] In the speaker device 1A, the rear surface of the first speaker 10A and the rear surface of the second speaker 20A contact the internal space of the cabinet 30A. Vibration caused by the diaphragm 2 of the second speaker 20A is transmitted through the internal space of the cabinet 30A to the diaphragm 2 of the first speaker 10A. The speaker device 1A controls the density of the internal space of the cabinet 30A.
[0046] In such a speaker device 1A, the air density in the internal space of the cabinet 30A can be suppressed, and the vibration direction of the air in the cabinet 30A can be aligned with the vibration direction of the diaphragm 2 of the first speaker 10A. The first speaker 10A and the second speaker 20A are arranged coaxially and in the same direction. As a result, when the diaphragm 2 of the first speaker 10A moves to compress (or expand) the internal space of the cabinet 30A, the diaphragm 2 of the second speaker 20A moves to expand (or compress) the internal space of the cabinet 30A, thereby suppressing the air density in the internal space of the cabinet 30A. In addition, when the diaphragm 2 of the first speaker 10A moves to the front side of the cabinet 30A, the diaphragm 2 of the second speaker 20A moves to the back side of the cabinet 30A, thereby suppressing the movement of the center of gravity of the cabinet 30A, and suppressing the vibration of the cabinet 30A.
[0047] In the speaker device 1A, the sound emitting surface of the second speaker 20A communicates with the outside J2. According to such a speaker device 1A, the second speaker 20A functions as an infinite baffle, so that bass sounds can be reproduced without a large enclosure. Therefore, the speaker device 1A is prevented from becoming large, and bass sounds can be reproduced.
[0048] In the speaker device 1A, the internal space of the cabinet 30A can be made a sealed space, and it is possible to prevent foreign matter from entering the internal space of the cabinet 30A from the outside J2. When the speaker device 1A is applied as an in-vehicle speaker, foreign matter such as water and dust is prevented from entering the internal space of the cabinet 30A from the outside J2, which is the space outside the vehicle. Since the intrusion of foreign matter into the inside of the cabinet 30A is prevented, the intrusion of foreign matter into the room J1 through the cabinet 30A is prevented.
[0049] Next, a speaker device 1B according to a second embodiment will be described. FIG. 6 is a cross-sectional view of the speaker device 1B. FIG. 7 is a side view of the speaker device 1B. The speaker device 1B according to the second embodiment is different from the speaker device 1A according to the first embodiment in that the arrangement of the second speaker 20B is different, the configuration of the cabinet 30B is different, and the phase control by the phase control unit 85B shown in FIG. 8 is different. In the description of the second embodiment, the differences from the first embodiment will be mainly described. The speaker device 1B includes a first speaker 10A and a second speaker 20B. The second speaker 20B is arranged in a direction opposite to that of the second speaker 20A of the first embodiment.
[0050] The second speaker 20B has a first surface 21 that communicates with the outside J2 and a second surface 22 that does not communicate with the outside J2. The first surface 21 of the second speaker 20B is a rear surface, and the second surface 22 is a sound emitting surface. The rear surface of the second speaker 20B communicates with the outside J2. In the Z direction, the rear surface of the first speaker 10A and the rear surface of the second speaker 20B face each other.
[0051] The speaker device 1B includes a cabinet 30B that holds the first speaker 10A and the second speaker 20B. The cabinet 30B is box-shaped and holds the first speaker 10A and the second speaker 20B. The cabinet 30B includes a front plate 31A, a back plate 32A, a side plate 33B, a side plate 34A, a side plate 35A, and a side plate 36A. The front plate 31A and the back plate 32A face each other in the Z direction. The side plate 33B and the side plate 34A face each other in the X direction. An opening 37B is formed in the side plate 33B. The opening 37B is formed at a position corresponding to the second speaker 20B in the Z direction. When viewed from the X direction, the diaphragm 2 and the driving unit 3 of the second speaker 20B are disposed in the opening 37B.
[0052] The cabinet 30B includes a first cabinet 40A, a second cabinet 50B, and a connecting portion 60B. The connecting portion 60B is disposed between the first cabinet 40A and the second cabinet 50B in the Z direction. The connecting portion 60B communicates between the first cabinet 40A and the second cabinet 50B.
[0053] The first cabinet 40A includes a first portion 43A of the side panel 33B, a first portion 44A of the side panel 34A, a first portion 45A of the side panel 35A, and a first portion 46A of the side panel 36A.
[0054] The first portion 43A of the side plate 33B and the first portion 44A of the side plate 34A face each other in the X direction.
[0055] The second cabinet 50B holds the second speaker 20B. The second cabinet 50B includes an inner wall plate 51B and a back plate 32A that face each other in the Z direction. The second cabinet 50B includes a second portion 53B of the side plate 33B, a second portion 54B of the side plate 34A, a second portion 55B of the side plate 35A, and a second portion 56B of the side plate 36A.
[0056] An opening 57B that holds the second speaker 20B is formed in the inner wall plate 51B. A speaker frame 4 of the second speaker 20B is fixed to the periphery surrounding the opening 57B. The diaphragm 2 and the drive unit 3 of the second speaker 20B are disposed outside the second cabinet 50B. The second speaker 20B is disposed between the back plate 42A of the first cabinet 40A and the inner wall plate 51B of the second cabinet 50B in the Z direction.
[0057] The second portion 53B of the side plate 33B and the second portion 54B of the side plate 34A face each other in the X direction. The second portion 55B of the side plate 35A and the second portion 56B of the side plate 36A face each other in the Y direction. In the X direction, an opening 58B is formed between the inner wall plate 51B and the side plate 34A.
[0058] The connecting portion 60B includes an inner wall plate 71B and a third portion 64B of the side plate 34A that face each other in the X direction. The internal space of the connecting portion 60B communicates with the internal space of the first cabinet 40A and the internal space of the second cabinet 50B. The second cabinet 50B and the connecting portion 60B communicate with each other through the opening 58B. The connecting portion 60B and the first cabinet 40A communicate with each other through the opening 47A.
[0059] The internal space of the cabinet 30B includes the internal space of the first cabinet 40A, the internal space of the second cabinet 50B, and the internal space of the connecting portion 60B. The internal space of the cabinet 30B is a closed space and is not connected to the indoor space J1 and the outdoor space J2. The second surface 12, which is the back surface of the first speaker 10A, and the second surface 22, which is the sound emitting surface of the second speaker 20B, are in contact with the internal space of the cabinet 30B.
[0060] An open space J4 that communicates with the outside J2 is formed on the rear side of the second speaker 20B. The open space J4 communicates with the outside J2 through the opening 37B. The open space J4 is formed in the Z direction between the rear panel 42A of the first cabinet 40A and the inner wall panel 51B of the second cabinet 50B.
[0061] The open space J4 is separated from the internal space of the cabinet 30B by the inner wall plate 71B, the inner wall plate 72B, and the inner wall plate 73B. The inner wall plate 72B and the inner wall plate 73B are disposed outside the second speaker 20B in the Y direction. The inner wall plate 72B faces the side plate 35A in the Y direction. The inner wall plate 73B faces the side plate 36A in the Y direction.
[0062] Next, an acoustic system 86B according to a second embodiment will be described with reference to Fig. 8. Fig. 8 is a block diagram of the acoustic system 86B. The acoustic system 86B includes a speaker device 1B and a phase control device 80B. The phase control device 80B includes a control unit 81.
[0063] The configuration of the phase control device 80B applied to the speaker device 1B is similar to that of the phase control device 80A of the first embodiment. The control unit 81 outputs an electric signal S1 to the first speaker 10A and outputs an electric signal S2 to the second speaker 20B.
[0064] The processing circuit 82 generates electric signals S1 and S2 that are in phase. As a result, the diaphragm 2 of the first speaker 10A and the diaphragm 2 of the second speaker 20B vibrate in the same direction. Here, "vibrating in the same direction" means that when the diaphragm 2 of the second speaker 20B moves toward the front, the diaphragm 2 of the first speaker 10A moves toward the front, and when the diaphragm 2 of the second speaker 20B moves toward the rear, the diaphragm 2 of the first speaker 10A moves toward the rear.
[0065] For example, when the diaphragm 2 of the second speaker 20B moves to the front side, the diaphragm 2 of the first speaker 10A moves to the front side. When the diaphragm 2 of the second speaker 20B moves to the front side, vibration is transmitted inside the cabinet 30B. In the cabinet 30B, the vibration is transmitted in the order of the internal space of the second cabinet 50B, the internal space of the connecting part 60B, and the internal space of the first cabinet 40A. In this way, when the vibration of the diaphragm 2 of the second speaker 20B moves to the front side, the vibration is transmitted to the diaphragm 2 of the first speaker 10A in the internal space of the first cabinet 40A so as to push the diaphragm 2 from the back side to the front side. The phase control unit 85B controls the phase of the electric signal S1 so that the diaphragm 2 of the first speaker 10A moves from the back side to the front side, and therefore the air density is suppressed in the internal space of the cabinet 30B.
[0066] Similarly, for example, when the diaphragm 2 of the second speaker 20B moves to the rear side, the diaphragm 2 of the first speaker 10A moves to the rear side. When the diaphragm 2 of the second speaker 20B moves to the rear side, vibration is transmitted inside the cabinet 30B. In the cabinet 30B, the vibration is transmitted to the internal space of the second cabinet 50B, the internal space of the connecting part 60B, and the internal space of the first cabinet 40A in that order. In this way, when the vibration of the diaphragm 2 of the second speaker 20B moves to the rear side, the vibration is transmitted to the diaphragm 2 of the first speaker 10A in the internal space of the first cabinet 40A so as to pull the diaphragm 2 to the rear side. The phase control unit 85B controls the phase of the electric signal S1 so that the diaphragm 2 of the first speaker 10A moves from the front side to the rear side, and therefore the air density is suppressed in the internal space of the cabinet 30B.
[0067] The delay circuit 84 can delay the electric signal S1 with respect to the electric signal S2. The delay circuit 84 delays the electric signal S1 with respect to the electric signal S2 according to the transmission path of the vibration from the second speaker 20B to the first speaker 10A. The transmission path of the vibration here refers to the transmission path of the vibration through the air inside the cabinet 30B. The delay circuit 84 delays the electric signal S1 so that the first speaker 10A vibrates in the same manner at the timing when the vibration of the second speaker 20B is transmitted to the first speaker 10A through the air inside the cabinet 30B. The phase control unit 85B controls the phase of the electric signal S1 and the electric signal S2 so that the phase of the vibration transmitted from the second speaker 20B to the first speaker 10A and the phase of the displacement of the diaphragm 2 due to the electric signal S1 input to the first speaker 10A are in phase. Note that when the vibration transmitted through the transmission path is small, the delay circuit 84 may be omitted. Furthermore, when the volume of cabinet 30B is small and the transmission path is short, a phase difference is unlikely to occur, and therefore delay circuit 84 may be omitted. In particular, when the resonance frequency of cabinet 30B is low (several tens to several hundreds of Hz), delay circuit 84 can be omitted.
[0068] In the speaker device 1B of the second embodiment, similarly to the speaker device 1A of the first embodiment, the variation in air density in the internal space of the cabinet 30B can be suppressed, and the movement of the center of gravity of the cabinet 30B can be suppressed.
[0069] Next, a speaker device 1C according to a third embodiment will be described. Fig. 9 is a cross-sectional view of the speaker device 1C. Fig. 10 is a side view of the speaker device 1C. A cabinet 30C of the speaker device 1C includes a first cabinet 40C that holds a first speaker 10B, a second cabinet 50C that holds a second speaker 20A, and a connecting portion 60C that connects the first cabinet 40C and the second cabinet 50C. The first speaker 10B is disposed in a direction opposite to that of the first speaker 10A of the first embodiment.
[0070] The first surface 11 of the first speaker 10A is a sound emitting surface, and the second surface 12 is a rear surface. The first surface 21 of the second speaker 20A is a rear surface, and the second surface 22 is a sound emitting surface. The sound emitting surface of the first speaker 10B communicates with the room J1, and the rear surface of the second speaker 20B communicates with the outside J2. In the Z direction, the sound emitting surface of the first speaker 10B and the sound emitting surface of the second speaker 20A face each other. In the speaker device 1C, the rear surface of the first speaker 10B and the sound emitting surface of the second speaker 20A are in contact with the internal space of the cabinet 30C.
[0071] The first cabinet 40C includes a front plate 31C and an inner wall plate 42C that face each other in the Z direction. The first speaker 10B is attached to an opening in the inner wall plate 42C. The back surface of the first speaker 10B faces the front plate 31C in the Z direction. The second cabinet 50C includes a back plate 32C and an inner wall plate 51C that face each other in the Z direction. The second speaker 20A is attached to an opening in the back plate 32C. The drive unit 3 of the second speaker 20A protrudes outward from the back plate 32C in the Z direction.
[0072] A communication space J5 communicating with the room J1 is formed between the first cabinet 40C and the second cabinet 50C. The communication space J5 is formed between the inner wall plate 42C and the inner wall plate 51C. The communication space J5 communicates with the room J1 through an opening 37C formed in the side plate 33C of the cabinet 30C.
[0073] The processing circuit 82 of the phase control device 80B applied to the speaker device 1C can generate an electric signal S1 and an electric signal S2 that are in phase. The delay circuit 84 can delay the electric signal S1 with respect to the electric signal S2. In the speaker device 1C of the third embodiment, similarly to the speaker device 1B of the second embodiment, the air density in the internal space of the cabinet 30C can be suppressed and the movement of the center of gravity of the cabinet 30C can be suppressed.
[0074] 11 is a cross-sectional view of a speaker device 1D according to Embodiment 4. A cabinet 30D of the speaker device 1D holds a first speaker 10A and a second speaker 20A.
[0075] The first surface 11 of the first speaker 10A is a sound emitting surface, and the second surface 12 is a rear surface. The first surface 21 of the second speaker 20A is a rear surface, and the second surface 22 is a sound emitting surface. The sound emitting surface of the first speaker 10A communicates with the room J1. The rear surface of the second speaker 20A communicates with the outside J2. In the Z direction, the rear surface of the first speaker 10A and the sound emitting surface of the second speaker 20A face each other. In the speaker device 1D, the rear surface of the first speaker 10A and the sound emitting surface of the second speaker 20A are in contact with the internal space of the cabinet 30D.
[0076] The processing circuit 82 of the phase control device 80B applied to the speaker device 1D can generate an electric signal S1 and an electric signal S2 that are in phase. In the speaker device 1D of the fourth embodiment, similarly to the speaker device 1A of the first embodiment, the air density in the internal space of the cabinet 30D can be suppressed.
[0077] 12 is a cross-sectional view of a speaker device 1E according to the fifth embodiment. A cabinet 30E of the speaker device 1E holds a first speaker 10A and a second speaker 20B.
[0078] The first surface 11 of the first speaker 10A is a sound emitting surface, and the second surface 12 is a rear surface. The first surface 21 of the second speaker 20B is a sound emitting surface, and the second surface 22 is a rear surface. The sound emitting surface of the first speaker 10A is in contact with a space communicating with the indoor space J1. The sound emitting surface of the second speaker 20B is in contact with a space communicating with the outdoor space J2. In the Z direction, the rear surface of the first speaker 10A and the rear surface of the second speaker 20B face each other. In the speaker device 1E, the rear surface of the first speaker 10A and the rear surface of the second speaker 20B are in contact with the internal space of the cabinet 30D.
[0079] The processing circuit 82 of the phase control device 80A applied to the speaker device 1E generates an electric signal S1 and an electric signal S2 having opposite phases. In the speaker device 1E of the fifth embodiment, similarly to the speaker device 1A of the first embodiment, the air density in the internal space of the cabinet 30E can be suppressed.
[0080] Fig. 13 is a cross-sectional view of the speaker device 1F according to the sixth embodiment. Fig. 14 is a side view of the speaker device 1F. Fig. 15 is a view taken along the line BB in Fig. 13. The speaker device 1F according to the sixth embodiment is different from the speaker device 1B according to the second embodiment in that the open space J6 is continuous in the X direction and that a connecting portion 60F is provided on each side of the second speaker 20B in the Y direction.
[0081] The speaker device 1F includes a first speaker 10A, a second speaker 20B, and a cabinet 30F. The cabinet 30F includes a first cabinet 40A that holds the first speaker 10A, a second cabinet 50B that holds the second speaker 20B, and a coupling portion 60F that couples the first cabinet 40A and the second cabinet 50B together.
[0082] In the cabinet 30F of the speaker device 1F, an opening 37F and an opening 38F are provided in a side plate 33F and a side plate 34F facing each other in the X direction. The opening 37F is provided in the side plate 33F, and the opening 38F is provided in the side plate 34F. The open space J6 is formed from the opening 37F to the opening 38F in the X direction. The connecting portion 60F is formed between the side plate 35F and the side plate 36F in the Y direction.
[0083] In the speaker device 1F of the sixth embodiment, similarly to the speaker device 1B of the second embodiment, it is possible to suppress the variation in air density in the internal space of the cabinet 30F and to suppress the movement of the center of gravity of the cabinet 30F.
[0084] Next, a speaker device 1G according to a seventh embodiment will be described. Fig. 16 is a front view of the speaker device 1G. Fig. 17 is a view taken along the line CC in Fig. 16. Fig. 18 is a view taken along the line DD in Fig. 16. The cross-sectional shape of the speaker device 1G shown in Fig. 17 is the same as the cross-sectional shape of the speaker device 1B of the second embodiment shown in Fig. 2. The cross-sectional shape of the speaker device 1G shown in Fig. 18 is obtained by turning the cross-sectional shape shown in Fig. 17 upside down.
[0085] The speaker device 1G includes a first speaker 10A, a second speaker 20B, and a cabinet 30G. The cabinet 30G includes a first cabinet 40G that holds the first speaker 10A, a second cabinet 50G that holds the second speaker 20B, and a connecting portion 60G that connects the first cabinet 40G and the second cabinet 50G.
[0086] The cabinet 30G includes a front panel 31G, a rear panel 32G, and a side panel 33G. The side panel 33G is formed to have a cylindrical shape. The side panel 33G is formed to surround the axis Z1 and the axis Z2.
[0087] The coupling portion 60G is formed between the first cabinet 40G and the second cabinet 50G in the Z direction. The internal space of the coupling portion 60G communicates with the internal space of the first cabinet 40G and the internal space of the second cabinet 50G. The cross-sectional shape of the coupling portion 60G is fan-shaped.
[0088] An opening 37G is formed in the side panel 33G. An open space J7 communicating with the outside J2 is formed on the rear side of the second speaker 20B. The open space J7 communicates with the outside J2 through the opening 37G. The openings 37G and the connecting portions 60G are alternately arranged in the circumferential direction of the side panel 33G. The first cabinet 40G and the second cabinet 50G are connected by, for example, three connecting portions 60G.
[0089] In the speaker device 1G of the seventh embodiment, similarly to the speaker device 1B of the second embodiment, the air density in the internal space of the cabinet 30G can be suppressed and the movement of the center of gravity of the cabinet 30G can be suppressed.
[0090] The cabinet 30G of the speaker device 1G has a circular outer shape. The speaker device 1G may be attached to a central opening of a spare tire. For example, in a trunk of a vehicle, the speaker device 1G may be held by the spare tire, with the first surface 11 of the first speaker 10A communicating with the interior of the vehicle compartment and the first surface 21 of the second speaker 20B communicating with the exterior of the vehicle compartment.
[0091] Next, sound distortion in a model of the first speaker 10A will be described with reference to Fig. 19 and Fig. 20. Fig. 19 is a schematic diagram showing a model of the first speaker 10A. The right side of the figure is the positive direction, and the left side of the figure is the negative direction. The sound emitting surface of the first speaker 10A is disposed in the positive direction, and the back surface is disposed in the negative direction.
[0092] FIG. 20 is a graph showing sound distortion in the model of the first speaker 10A shown in FIG. 19. The horizontal axis shows the electric signal, and the vertical axis shows the displacement of the diaphragm 2. Graph G1 shown in FIG. 20 shows the relationship between the electric signal and the displacement of the diaphragm 2 in the model of the first speaker 10A. Due to the structure of the speaker, there is no symmetry in the displacement of the diaphragm 2 in the positive and negative directions with respect to the electric signal. This is sound distortion, or second-order distortion.
[0093] Next, with reference to Fig. 21 and Fig. 22, a description will be given of sound distortion in a model of a speaker device 91 including a first speaker 10A and a second speaker 20A arranged in the same direction. Fig. 21 is a schematic diagram showing a model of the speaker device 91. In the speaker device 91, the sound emitting surface of the first speaker 10A is arranged in the positive direction, and the back surface is arranged in the negative direction. The sound emitting surface of the second speaker 20A is arranged in the positive direction, and the back surface is arranged in the negative direction.
[0094] Fig. 22 is a graph showing sound distortion in the model of the speaker device 91 shown in Fig. 21. Graph G2 shown in Fig. 22 is a graph showing the relationship between the electric signal and the displacement of the diaphragm 2 in the model of the second speaker 20A. When the first speaker 10A and the second speaker 20A are arranged in the same direction and sound is output, similar distortion appears in the displacement of the diaphragm 2 of the first speaker 10A and the displacement of the diaphragm 2 of the second speaker 20A.
[0095] Next, with reference to Fig. 23 and Fig. 24, a description will be given of sound distortion in a model of a speaker device 92 including a first speaker 10A and a second speaker 20B arranged in opposite directions. Fig. 23 is a schematic diagram showing a model of the speaker device 92. In the speaker device 92, the sound emitting surface of the first speaker 10A is arranged in the positive direction, and the back surface is arranged in the negative direction. The sound emitting surface of the second speaker 20B is arranged in the negative direction, and the back surface is arranged in the positive direction.
[0096] FIG. 24 is a graph showing sound distortion in the model of the speaker device 92 shown in FIG. 23. Graph G3 shown in FIG. 24 is a graph showing the relationship between the electric signal and the displacement of the diaphragm 2 in the model of the second speaker 20B. The speaker device 92 outputs the electric signal S1 and the electric signal S2 of opposite phases to the first speaker 10A and the second speaker 20B. In this case, the displacement of the diaphragm 2 by the speaker device 92 reduces distortion as shown in graph G3. Graph G3 is symmetrical about the 0 point in the positive and negative directions. This results in third-order distortion that has little effect on sound quality.
[0097] It should be noted that the above-described embodiments merely illustrate typical forms of the present disclosure, and the present disclosure is not limited to the above-described embodiments, and various modifications and additions are possible without departing from the gist of the present disclosure.
[0098] In the above-described embodiment, the indoor J1 and the outdoor J2 are illustrated, but the indoor J1 and the outdoor J2 may be reversed. For example, in the first embodiment shown in FIG. 1, the side indicated by the symbol J1 may be the outdoor side, and the side indicated by the symbol J2 may be the indoor side. In this case, the speaker indicated by the symbol 10A is the second speaker, and the speaker indicated by the symbol 20A is the first speaker. In the second to seventh embodiments, the indoor J1 and the outdoor J2 may be reversed.
[0099] In the speaker device 1A, the second surface 12 of the first speaker 10A may be the sound emitting surface. In this case, the back surface of the first speaker 10A communicates with the room J1, and the sound emitting surface does not communicate with the room J1. In the speaker device 1A, the second surface 12 of the first speaker 10A may be the sound emitting surface, and the second surface 22 of the second speaker 20A may be the sound emitting surface. In the speaker device 1A, the second surface 12 of the first speaker 10A may be the sound emitting surface, and the second surface 22 of the second speaker 20A may be the back surface. In the speaker device 1A, the sound emitting surfaces of the first speaker 10A and the second speaker 20A may be arranged to face each other.
[0100] In the above embodiment, the first speaker 10A and the second speaker 20A are supplied with sound signals of opposite phases, but sound signals of other phases can also be supplied. In the above embodiment, the first speaker 10A and the second speaker 20B are supplied with sound signals of the same phase, but sound signals of other phases can also be supplied.
[0101] In the above embodiment, the first speaker 10A and the second speaker 20A are arranged coaxially, but the arrangement of the first speaker 10A and the second speaker 20A is not limited to being coaxial. The axis Z1 of the first speaker 10A and the axis Z2 of the second speaker are parallel, and the first speaker 10A and the second speaker 20A may overlap when viewed from a direction along the axis Z1 of the first speaker 10A.
[0102] The axis Z1 of the first speaker 10A and the axis Z2 of the second speaker 20A do not have to be parallel to each other. The axis Z1 may be inclined with respect to the axis Z2.
[0103] In the above-described embodiment, the phase control unit 85A may change the phase control depending on the frequency. For example, the phase control unit 84A may not change the phase when the frequency is 100 Hz or less, and may reverse the phase when the frequency exceeds 100 Hz. [Explanation of symbols]
[0104] 1A, 1B, 1C, 1D, 1E, 1F, 1G...speaker device, 10A, 10B...first speaker, 11...first surface, 12...second surface, 20A, 20B...second speaker, 21...first surface, 22...second surface, 30A, 30B, 30C, 30D, 30E, 30F, 30G...cabinet, 85A, 85B...phase control section, 86A, 86B...acoustic system, J1...indoor, J2...outdoor, Z1...axis, Z2...axis.
Claims
1. a first speaker having a first surface communicating with an interior of a vehicle compartment and a second surface not communicating with the interior of the vehicle compartment; a second speaker having a first surface communicating with the outside of the vehicle and a second surface not communicating with the outside of the vehicle; A cabinet having a boundary surface that forms a closed space; Equipped with the second surface of the first speaker is a rear surface; the second surface of the second speaker is a rear surface; An audio signal is provided to the first speaker; The speaker device is disposed at the boundary, with the second surface of the first speaker and the second surface of the second speaker facing the closed space.
2. a first speaker having a first surface communicating with an interior of a vehicle compartment and a second surface not communicating with the interior of the vehicle compartment; a second speaker having a first surface communicating with the outside of the vehicle and a second surface not communicating with the outside of the vehicle; A cabinet having a boundary surface that forms a closed space; Equipped with a second surface of the first speaker being a sound emitting surface; a second surface of the second speaker is a sound emitting surface; An audio signal is provided to the first speaker; The speaker device is disposed at the boundary, with the second surface of the first speaker and the second surface of the second speaker facing the closed space.
3. The first speaker and the second speaker are arranged coaxially and in the same direction.
3. The speaker device according to claim 1 or 2.
4. a first speaker having a first surface communicating with an interior of a vehicle compartment and a second surface not communicating with the interior of the vehicle compartment; a second speaker having a first surface communicating with the outside of the vehicle and a second surface not communicating with the outside of the vehicle; A cabinet having a boundary surface that forms a closed space; Equipped with the second surface of the first speaker is a rear surface; a second surface of the second speaker is a sound emitting surface; An audio signal is provided to the first speaker; The speaker device is disposed at the boundary, with the second surface of the first speaker and the second surface of the second speaker facing the closed space.
5. a first speaker having a first surface communicating with an interior of a vehicle compartment and a second surface not communicating with the interior of the vehicle compartment; a second speaker having a first surface communicating with the outside of the vehicle and a second surface not communicating with the outside of the vehicle; A cabinet having a boundary surface that forms a closed space; Equipped with a second surface of the first speaker being a sound emitting surface; the second surface of the second speaker is a rear surface; An audio signal is provided to the first speaker; The speaker device is disposed at the boundary, with the second surface of the first speaker and the second surface of the second speaker facing the closed space.
6. The first speaker and the second speaker are arranged coaxially with their backs facing each other.
6. The speaker device according to claim 4 or 5.
7. The speaker device according to claim 4 , wherein the sound emitting surfaces of the first speaker and the second speaker are arranged to face each other.
8. The speaker device according to any one of claims 1 to 7, a phase control unit that generates a first sound signal and a second sound signal, which are two sound signals having a phase difference, and supplies the first sound signal to the first speaker and the second sound signal to the second speaker, Sound system.
Citation Information
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