Speaker equipment and sound systems

Abstract

To enable bass reproduction while suppressing a vibration of a speaker device.SOLUTION: A speaker device 1A includes: a first speaker 10A having a first surface 11 communicating with an interior side J1 and a second surface 12 not communicating with the interior side J1; a second speaker 20A having a first surface 21 communicating with an exterior side J2 and a second surface 22 not communicating with the exterior side J2; and a cabinet 30A for forming a closed space by surfaces which form a boundary. The second surface 12 of the first speaker 10A and the second surface 22 of the second speaker 20A are arranged on the boundary.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a speaker device and an audio system.

Background Art

[0002] In a speaker device, there is a technique of arranging the back surface of the speaker facing the outside of the vehicle to form an infinite baffle (see, for example, Patent Document 1). In a speaker device including a main speaker and an auxiliary speaker, there is a technique of installing the auxiliary speaker with its sound emission surface facing 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 Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a speaker device, a large enclosure is required to reproduce low frequencies. However, there are cases where a large enclosure cannot be installed, such as when the installation space of the speaker device is limited.

[0005] Also, when the speaker device cannot be firmly attached to another object, the reproduced energy changes from sound to vibration. Further, when the installation location of the speaker device is complicated or weight reduction of the speaker device is required, it may be necessary to thin the enclosure. In this case, it becomes difficult to attach the enclosure to another object.

[0006] This disclosure provides a speaker device and an acoustic system that enable bass reproduction while suppressing vibrations of the speaker device. [Means for solving the problem]

[0007] A speaker device according to 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 a room and a second surface not communicating with the exterior of a room, and a cabinet in which a closed space is formed by surfaces forming a boundary, wherein the second surface of the first speaker is the rear surface, the second surface of the second speaker is the rear surface, an audio signal is supplied to the first speaker, and the second surfaces of the first speaker and the second speaker are positioned at the boundary facing the closed space. A speaker device according to a second aspect of the present disclosure comprises a first speaker having a first surface communicating with the interior of a vehicle and a second surface not communicating with the interior of the vehicle, 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 surfaces forming a boundary, wherein the second surface of the first speaker is a sound-emitting surface, the second surface of the second speaker is a sound-emitting surface, an audio signal is supplied to the first speaker, and the second surfaces of the first speaker and the second speaker are positioned at the boundary facing the closed space. A speaker device according to a third aspect of the present disclosure comprises a first speaker having a first surface communicating with the interior of a vehicle and a second surface not communicating with the interior of the vehicle, 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 surfaces forming a boundary, wherein the second surface of the first speaker is the rear surface, the second surface of the second speaker is the sound-emitting surface, an audio signal is supplied to the first speaker, and the second surfaces of the first speaker and the second speaker are positioned at the boundary facing the closed space. A speaker device according to a fourth aspect of the present disclosure comprises a first speaker having a first surface communicating with the interior of a vehicle and a second surface not communicating with the interior of the vehicle, 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 surfaces forming a boundary, wherein the second surface of the first speaker is a sound-emitting surface, the second surface of the second speaker is a rear surface, an audio signal is supplied to the first speaker, and the second surfaces of the first speaker and the second speaker are positioned at the boundary facing the closed space.

[0008] The acoustic system of this disclosure comprises a speaker device in any of the above-described embodiments and a phase control unit that generates a first sound signal and a second sound signal, which are two sound signals with a phase difference, and supplies the first sound signal to the first speaker and the second sound signal to the second speaker. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view of the speaker device according to the first embodiment. [Figure 2] This is a side view of the speaker device according to the first embodiment. [Figure 3] This is a front view of the speaker device according to the first embodiment. [Figure 4] This is a view taken along line AA in Figure 1. [Figure 5] This is a block diagram of the acoustic system according to the first embodiment. [Figure 6] This is a cross-sectional view of a speaker device according to the second embodiment. [Figure 7] This is a side view of the speaker device according to the second embodiment. [Figure 8] This is a block diagram of the acoustic system according to the second embodiment. [Figure 9] This is a cross-sectional view of a speaker device according to the third embodiment. [Figure 10] This is a side view of the speaker device according to the third embodiment. [Figure 11] Cross-sectional view of the speaker device according to the fourth embodiment. [Figure 12] Cross-sectional view of the speaker device according to the fifth embodiment. [Figure 13] Cross-sectional view of the speaker device according to the sixth embodiment. [Figure 14] Side view of the speaker device according to the sixth embodiment. [Figure 15] View taken in the direction of arrow B-B in FIG. 13. [Figure 16] Front view of the speaker device according to the seventh embodiment. [Figure 17] View taken in the direction of arrow C-C in FIG. 16. [Figure 18] View taken in the direction of arrow D-D in FIG. 16. [Figure 19] Schematic view showing the model of the first speaker. [Figure 20] Graph showing the distortion of sound in the model of the first speaker shown in FIG. 19. [Figure 21] Schematic view showing the model of the speaker device including the first speaker and the second speaker arranged in the same direction. [Figure 22] Graph showing the distortion of sound in the model of the speaker device shown in FIG. 21. [Figure 23] Schematic view showing the model of the speaker device including the first speaker and the second speaker arranged in the opposite direction. [Figure 24] Graph showing the distortion of sound in the model of the speaker device shown in FIG. 23.

Embodiments for Carrying Out the Invention

[0010] Embodiments of the present disclosure will be described below with reference to the drawings. Note that the dimensions and scale of the parts in the drawings have been appropriately altered from those of the actual parts. Furthermore, the embodiments described below are preferred specific examples of the present invention. For this reason, these embodiments are subject to various technically preferred limitations. However, the scope of the present disclosure is not limited to these embodiments unless otherwise specifically stated in the following description.

[0011] Figure 1 is a cross-sectional view of speaker device 1A according to the first embodiment. Figure 2 is a side view of speaker device 1A. Figure 3 is a front view of speaker device 1A. Figure 4 is a view taken along line AA in Figure 1. The speaker device 1A shown in Figures 1 to 4 can be used, for example, as an in-vehicle speaker device mounted in a vehicle such as an automobile. The speaker device 1A may be attached to the door of a vehicle, for example, via a door trim. Note that the use of speaker device 1A is not limited to in-vehicle use and may be used for other purposes as well.

[0012] The speaker device 1A comprises a first speaker 10A and a second speaker 20A. Figure 1 shows a cross-section of a portion of the speaker device 1A. This cross-section is obtained by cutting the speaker device 1A through a plane containing the axis Z1 of the first speaker 10A and the axis Z2 of the second speaker 20A. The axis Z1 is a line segment parallel to the vibration direction of the diaphragm 2, which will be described later, and passing through the center of the diaphragm 2. The direction of the axis Z1 is the direction in which the axis Z1 extends.

[0013] In the description of the first speaker 10A, the side on which the diaphragm 2 is positioned in the direction of axis Z1 is the front side, and the opposite side is the back side. Of the two planes spaced apart in the direction of axis Z1, the plane on which the diaphragm 2 is positioned is the sound-emitting surface, and the opposite plane is the back side. The same applies to axis Z2. Furthermore, the three mutually orthogonal directions are denoted as the X direction, Y direction, and Z direction. The Z direction is parallel to the direction of axis Z1.

[0014] In the description of cabinet 30A, which will be explained later, the right side in the diagram is considered the front side, and the left side in the diagram is considered the rear side. In other embodiments, which will be explained later, the front and rear sides of the cabinet may not be the same as the front and rear sides of the first speaker, or the front and rear sides of the second speaker.

[0015] The first speaker 10A and the second speaker 20A have the same configuration, although they 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. Axes Z1 and Z2 are coaxial.

[0016] The diaphragm 2 is a vibrating body composed of a sheet material that emits sound through vibration. The sheet material is obtained, for example, by impregnating a fibrous substrate with a resin material and then curing or solidifying it. Examples of the resin material include acrylic resin, polyurethane, melamine resin, modified rubber resin, and phenolic resin. Examples of the fibrous substrate 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 axis Z2. The diaphragm 2 is cone-shaped. However, the shape of the diaphragm 2 is not limited to a cone shape; for example, it may be dome-shaped or the like.

[0018] The drive unit 3 is a mechanism that drives the diaphragm 2 based on an input electrical signal. The drive 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 electrical signal is input, the voice coil vibrates the diaphragm 2 through the interaction of magnetic forces with the magnet. This vibration causes the diaphragm 2 to emit sound based on the electrical signal. Note that the drive unit 3 only needs to be able to drive the diaphragm 2 based on an electrical signal and is not limited to a configuration having a voice coil and a magnet; it can be any configuration.

[0019] The first speaker 10A has a first surface 11 that communicates with the indoor space J1 and a second surface 12 that does not communicate with the indoor space J1. The second speaker 20A has a first surface 21 that communicates with the outdoor space J2 and a second surface 22 that does not communicate with the outdoor space J2. Communicating with the indoor space J1 means being in contact with the space of the indoor space J1 and not in contact with the internal space of the cabinet 30A, which will be described later. Not communicating with the indoor space J1 means being in contact with the internal space of the cabinet 30A and not in contact with the space of the indoor space J1. Communicating with the outdoor space J2 means being in contact with the space of the outdoor space J2 and not in contact with the internal space of the cabinet 30A. Not communicating with the outdoor space J2 means being in contact with the internal space of the cabinet 30A and not in contact with the space of the outdoor space J2.

[0020] When speaker device 1A is installed in a car, the interior J1 is the interior of the car, and the exterior J2 is the exterior of the car. When speaker device 1A is installed in the door of a car, even if the first surface 11 of the first speaker 10A is in contact with the outside of the car when the door is open, if it is in contact with the interior of the car when the door is closed, the first surface 11 is in contact with the interior J1. Also, if the first surface 21 of the second speaker 20A is in contact with the space in an opening that communicates with the outside of the car, the first surface 21 communicates with the exterior J2. The interior of the car remains the interior J1 even if it communicates with the outside of the car when the door or window is open.

[0021] The first surface 11 of the first speaker 10A is the sound-emitting surface, and the second surface 12 is the rear surface. The first surface 21 of the second speaker 20A is the sound-emitting surface, and the second surface 22 is the rear surface. The sound-emitting surface of the first speaker 10A is in communication with the indoor J1, and the sound-emitting surface of the second speaker 20A is in communication with the outdoor J2.

[0022] The speaker device 1A includes a cabinet 30A that holds a first speaker 10A and a 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 panel 31A, a rear panel 32A, a side panel 33A, a side panel 34A, a side panel 35A, and a side panel 36A. The front panel 31A and the rear panel 32A face each other in the Z direction. The side panels 33A and 34A face each other in the X direction. The side panels 35A and 36A face each other in the Y direction. An opening 37A is formed in the side panel 33A. The opening 37A is formed in the center of the side panel 33A in the Z direction.

[0023] Cabinet 30A forms a closed space on the boundary-forming surfaces. The boundary-forming surfaces include the front panel 31A, the rear panel 32A, the side panels 33A, 34A, 35A, and 36A. The boundary-forming surfaces also include the rear panel 42A of the first cabinet 40A and the front panel 51A of the second cabinet 50A, which will be described later. The boundary-forming surfaces also include the inner wall panels 71A, 72A, and 73A of the connecting section 60A, which will be described later. Cabinet 30A forms a closed space, which is a closed internal space, when the first speaker 10A and the second speaker 20A are held in place. Forming a closed space on the boundary-forming surfaces includes forming a closed internal space when the first speaker 10A and the second speaker 20A are held in place.

[0024] The second surface 12 of the first speaker 10A and the second surface 22 of the second speaker 20A are positioned at the boundary of the cabinet 30A facing the enclosed space. Positioning the second surfaces 12 and 22 at the boundary of the cabinet 30A facing the enclosed space includes positioning them 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 the side panels 33A to 36A of the cabinet 30A. The speaker device 1A is attached to other components via the mounting piece 8. Outside the speaker device 1A, the area in front of the mounting piece 8 is the indoor J1, and the area behind the mounting piece 8 is the outdoor J2. The mounting piece 8 may be a flange, a channel, or the like.

[0026] Cabinet 30A comprises a first cabinet 40A, a second cabinet 50A, and a connecting section 60A. The connecting section 60A is positioned between the first cabinet 40A and the second cabinet 50A in the Z direction. The connecting section 60A connects 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 facing each other in the Z direction. The first cabinet 40A includes a first portion 43A of a side panel 33A, a first portion 44A of a side panel 34A, a first portion 45A of a side panel 35A, and a first portion 46A of a side panel 36A.

[0028] An opening 38A for holding the first speaker 10A is formed in the front panel 31A. The speaker frame 4 of the first speaker 10A is fixed to the periphery of the opening 38A. The diaphragm 2 and drive unit 3 of the first speaker 10A are housed in the first cabinet 40A.

[0029] The first portion 43A of side panel 33A and the first portion 44A of side panel 34A face each other in the X direction. The first portion 45A of side panel 35A and the first portion 46A of side panel 36A face each other in the Y direction. In the X direction, an opening 47A is formed between the back panel 42A and the side panel 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 facing each other in the Z direction. The second cabinet 50A includes a second portion 53A of a side panel 33A, a second portion 54A of a side panel 34A, a second portion 55A of a side panel 35A, and a second portion 56A of a side panel 36A.

[0031] An opening 57A for holding the second speaker 20A is formed in the front panel 51A. The speaker frame 4 of the second speaker 20A is fixed to the periphery of the opening 57A. The diaphragm 2 and drive unit 3 of the second speaker 20A are housed inside the second cabinet 50A.

[0032] The second portion 53A of side panel 33A and the second portion 54A of side panel 34A face each other in the X direction. The second portion 55A of side panel 35A and the second portion 56A of side panel 36A face each other in the Y direction. In the X direction, an opening 58A is formed between the front panel 51A and the side panel 34A.

[0033] The connecting section 60A includes an inner wall plate 71A and a third portion 64A of the side plate 34A that are facing each other in the X direction. The internal space of the connecting section 60A communicates with the internal space of the first cabinet 40A and the internal space of the second cabinet 50A through openings 47A and 58A.

[0034] The internal space of 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 section 60A. The internal space of cabinet 30A is a closed space and is not in communication with the indoor J1 and outdoor J2. The second surface 12, which is the back of the first speaker 10A, and the second surface 22, which is the back of the second speaker 20A, are in contact with the internal space of cabinet 30A.

[0035] An open space J3 is formed on the front side of the second speaker 20A, communicating with the outdoor area J2. The open space J3 communicates with the outdoor area J2 through an opening 37A. In the Z direction, the open space J3 includes a space formed between the rear panel 42A of the first cabinet 40A and the front panel 51A of the second cabinet 50A.

[0036] As shown in Figure 4, the open space J3 is separated from the internal space of the cabinet 30A by inner wall panels 71A, 72A, and 73A. Inner wall panels 72A and 73A are positioned outside the second speaker 20A in the Y direction. Inner wall panel 72A faces side panel 35A in the Y direction. Inner wall panel 73A faces side panel 36A in the Y direction.

[0037] Next, an acoustic system 86A according to the first embodiment will be described with reference to Figure 5. Figure 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 electrical signals S1 and S2 output to the first speaker 10A and the second speaker 20A. The control unit 81 has a processing circuit 82 such as a CPU (Central Processing Unit) or FPGA (Field Programmable Gate Array) and a storage circuit 83 such as a semiconductor memory.

[0038] The memory circuit 83 stores the control program and various parameters used for controlling the phase of electrical signals. The memory circuit 83 also functions as a workspace for the processing circuit 82. The processing circuit 82 reads the control program from the memory circuit 83. By executing the read control program, the processing circuit 82 functions as the control center for the speaker device 1A. The control unit 81 outputs electrical signal S1 to the first speaker 10A and electrical 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 electrical signal S1 output to the first speaker 10A and the electrical 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 with a phase difference. The first sound signal is the electrical signal S1. The second sound signal is the electrical signal S2.

[0040] The processing circuit 82 generates electrical signals S1 and S2 that are out of phase with respect 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. Here, "vibrating in opposite directions" means that when the diaphragm 2 of the second speaker 20A moves forward, the diaphragm 2 of the first speaker 10A moves backward, and when the diaphragm 2 of the second speaker 20A moves backward, the diaphragm 2 of the first speaker 10A moves forward.

[0041] For example, when the diaphragm 2 of the second speaker 20A moves to the rear, the diaphragm 2 of the first speaker 10A moves to the front. When the diaphragm 2 of the second speaker 20A moves to the rear, vibration is transmitted into the cabinet 30A. In the cabinet 30A, the vibration is transmitted in the following order: 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, vibration is transmitted in the internal space of the first cabinet 40A to the diaphragm 2 of the first speaker 10A in such a way that it pushes the diaphragm 2 from the rear to the front. The phase control unit 85 controls the phase of the electrical signal S1 so that the diaphragm 2 of the first speaker 10A moves from the rear to the front, so that the compression and rarefaction of the air in the internal space of the cabinet 30A is suppressed. Suppression of air compression and rarefaction means that pressure changes inside the cabinet 30A are suppressed.

[0042] Similarly, for example, when the diaphragm 2 of the second speaker 20A moves to the front, the diaphragm 2 of the first speaker 10A moves to the rear. When the diaphragm 2 of the second speaker 20A moves to the front, vibration is transmitted into the cabinet 30A. In the cabinet 30A, the vibration is transmitted in the following order: the internal space of the second cabinet 50A, the internal space of the connecting section 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, vibration is transmitted in the internal space of the first cabinet 40A to the diaphragm 2 of the first speaker 10A in a manner that pulls the diaphragm 2 from the rear. The phase control unit 85 controls the phase of the electrical signal S1 so that the diaphragm 2 of the first speaker 10A moves from the front to the rear, thereby suppressing the compression and rarefaction of air 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 electrical signal S1 and the phase of electrical signal S2 are in opposite phase. However, in the cabinet 30A, the vibration of the second speaker 20A is transmitted to the first speaker 10A through the air in the internal space. Consequently, 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 electrical signal S1 relative to the electrical signal S2. The delay circuit 84 delays the electrical signal S1 relative to the electrical signal S2 according to the vibration transmission path from the second speaker 20A to the first speaker 10A. The vibration transmission path here refers to the vibration transmission path through the air inside the cabinet 30A. The delay circuit 84 delays the electrical signal S1 so that the first speaker 10A vibrates in the same way 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 electrical signals S1 and 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 electrical signal S1 input to the first speaker 10A are in opposite phase. Note that if the vibration transmitted through the transmission path is small, the delay circuit 84 may be omitted. Furthermore, if the volume of cabinet 30A is small and the transmission path is short, a phase difference is less likely to occur, so the delay circuit 84 may be omitted. In particular, if the resonant frequency of cabinet 30A is low (tens to hundreds of Hz), the delay circuit 84 can be omitted.

[0045] In speaker device 1A, the backs of the first speaker 10A and the second speaker 20A are in contact with the internal space of the cabinet 30A. Vibrations from the diaphragm 2 of the second speaker 20A are transmitted through the internal space of the cabinet 30A and transmitted to the diaphragm 2 of the first speaker 10A. Speaker device 1A controls the density of the internal space of the cabinet 30A.

[0046] In such a speaker device 1A, the compression and rarefaction of the air inside the cabinet 30A can be suppressed, and the direction of vibration of the air inside the cabinet 30A can be matched with the direction of vibration 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 orientation. As a result, when the diaphragm 2 of the first speaker 10A moves to compress (or expand) the inside space of the cabinet 30A, the diaphragm 2 of the second speaker 20A moves to expand (or compress) the inside space of the cabinet 30A, thereby suppressing the compression and rarefaction of the air inside the cabinet 30A. In addition, when the diaphragm 2 of the first speaker 10A moves towards the front of the cabinet 30A, the diaphragm 2 of the second speaker 20A moves towards the rear of the cabinet 30A, thereby suppressing the shift in the center of gravity of the cabinet 30A and suppressing the vibration of the cabinet 30A.

[0047] In speaker system 1A, the sound-emitting surface of the second speaker 20A is connected to the outdoor J2. With such speaker system 1A, the second speaker 20A functions as an infinite baffle, eliminating the need for a large enclosure and enabling bass reproduction. Therefore, the size of speaker system 1A is avoided, while bass reproduction is achieved.

[0048] In speaker device 1A, the internal space of cabinet 30A can be made into a sealed space, preventing foreign matter from entering the internal space of cabinet 30A from the outside J2. When speaker device 1A is applied as a car speaker, the entry of foreign matter such as water and dust from the outside space J2 into the internal space of cabinet 30A is prevented. Since the entry of foreign matter into the inside of cabinet 30A is prevented, the entry of foreign matter into the interior J1 via cabinet 30A is also prevented.

[0049] Next, a speaker device 1B according to the second embodiment will be described. Figure 6 is a cross-sectional view of the speaker device 1B. Figure 7 is a side view of the speaker device 1B. The differences between the speaker device 1B according to the second embodiment and the speaker device 1A according to the first embodiment are the arrangement of the second speaker 20B, the configuration of the cabinet 30B, and the phase control by the phase control unit 85B shown in Figure 8. In describing the second embodiment, the differences from the first embodiment will be mainly explained. The speaker device 1B includes a first speaker 10A and a second speaker 20B. The second speaker 20B is arranged in the opposite direction to the second speaker 20A in the first embodiment.

[0050] The second speaker 20B has a first surface 21 that communicates with the outdoor J2 and a second surface 22 that does not communicate with the outdoor J2. The first surface 21 of the second speaker 20B is the back surface, and the second surface 22 is the sound-emitting surface. The back surface of the second speaker 20B communicates with the outdoor J2. In the Z direction, the back surface of the first speaker 10A and the back surface of the second speaker 20B face each other.

[0051] The speaker device 1B includes a cabinet 30B that holds a first speaker 10A and a 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 panel 31A, a rear panel 32A, side panels 33B, side panels 34A, side panels 35A, and side panels 36A. The front panel 31A and the rear panel 32A face each other in the Z direction. The side panels 33B and 34A face each other in the X direction. An opening 37B is formed in the side panel 33B. The opening 37B is formed in the Z direction at a position corresponding to the second speaker 20B. When viewed from the X direction, the diaphragm 2 and drive unit 3 of the second speaker 20B are arranged within the opening 37B.

[0052] Cabinet 30B comprises a first cabinet 40A, a second cabinet 50B, and a connecting section 60B. The connecting section 60B is positioned between the first cabinet 40A and the second cabinet 50B in the Z direction. The connecting section 60B connects 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 side panel 33B and the first portion 44A of side panel 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 panel 51B and a rear panel 32A facing each other in the Z direction. The second cabinet 50B includes a second portion 53B of the side panel 33B, a second portion 54B of the side panel 34A, a second portion 55B of the side panel 35A, and a second portion 56B of the side panel 36A.

[0056] An opening 57B for holding the second speaker 20B is formed in the inner wall panel 51B. The speaker frame 4 of the second speaker 20B is fixed to the periphery surrounding the opening 57B. The diaphragm 2 and drive unit 3 of the second speaker 20B are located outside the second cabinet 50B. In the Z direction, the second speaker 20B is positioned between the back panel 42A of the first cabinet 40A and the inner wall panel 51B of the second cabinet 50B.

[0057] The second portion 53B of side panel 33B and the second portion 54B of side panel 34A face each other in the X direction. The second portion 55B of side panel 35A and the second portion 56B of side panel 36A face each other in the Y direction. In the X direction, an opening 58B is formed between the inner wall panel 51B and the side panel 34A.

[0058] The connecting section 60B includes an inner wall plate 71B and a third portion 64B of the side plate 34A that are facing each other in the X direction. The internal space of the connecting section 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 section 60B are connected through the opening 58B. The connecting section 60B and the first cabinet 40A are connected through the opening 47A.

[0059] The internal space of 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 section 60B. The internal space of cabinet 30B is a closed space and is not in communication with the indoor J1 and outdoor J2. The second surface 12, which is the back 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 cabinet 30B.

[0060] An open space J4 is formed on the rear side of the second speaker 20B, which communicates with the outdoor area J2. The open space J4 communicates with the outdoor area J2 through the opening 37B. In the Z direction, the open space J4 is formed 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 inner wall panels 71B, 72B, and 73B. In the Y direction, inner wall panels 72B and 73B are positioned outside the second speaker 20B. In the Y direction, inner wall panel 72B faces side panel 35A. In the Y direction, inner wall panel 73B faces side panel 36A.

[0062] Next, an acoustic system 86B according to the second embodiment will be described with reference to Figure 8. Figure 8 is a block diagram of the acoustic system 86B. The acoustic system 86B comprises 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 the same as the configuration of the phase control device 80A in the first embodiment. The control unit 81 outputs electrical signal S1 to the first speaker 10A and electrical signal S2 to the second speaker 20B.

[0064] The processing circuit 82 generates in-phase electrical signals S1 and S2. 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. "Vibrating in the same direction" means that when the diaphragm 2 of the second speaker 20B moves forward, the diaphragm 2 of the first speaker 10A also moves forward, and when the diaphragm 2 of the second speaker 20B moves backward, the diaphragm 2 of the first speaker 10A also moves backward.

[0065] For example, when the diaphragm 2 of the second speaker 20B moves to the front, the diaphragm 2 of the first speaker 10A also moves to the front. When the diaphragm 2 of the second speaker 20B moves to the front, vibrations are transmitted into the cabinet 30B. In the cabinet 30B, vibrations are transmitted in the following order: the internal space of the second cabinet 50B, the internal space of the connecting section 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, vibrations are transmitted in the internal space of the first cabinet 40A to the diaphragm 2 of the first speaker 10A in such a way that it pushes the diaphragm 2 from the rear to the front. The phase control unit 85B controls the phase of the electrical signal S1 so that the diaphragm 2 of the first speaker 10A moves from the rear to the front, thereby suppressing air compression and rarefaction in the internal space of the cabinet 30B.

[0066] Similarly, for example, if the diaphragm 2 of the second speaker 20B moves to the rear, the diaphragm 2 of the first speaker 10A also moves to the rear. When the diaphragm 2 of the second speaker 20B moves to the rear, vibration is transmitted into the cabinet 30B. In the cabinet 30B, the vibration is transmitted in the following order: the internal space of the second cabinet 50B, the internal space of the connecting section 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 rear, vibration is transmitted to the diaphragm 2 of the first speaker 10A in the internal space of the first cabinet 40A in such a way that it pulls the diaphragm 2 to the rear. The phase control unit 85B controls the phase of the electrical signal S1 so that the diaphragm 2 of the first speaker 10A moves from the front to the rear, thereby suppressing the compression and rarefaction of air in the internal space of the cabinet 30B.

[0067] The delay circuit 84 can delay the electrical signal S1 relative to the electrical signal S2. The delay circuit 84 delays the electrical signal S1 relative to the electrical signal S2 according to the vibration transmission path from the second speaker 20B to the first speaker 10A. The vibration transmission path here refers to the vibration transmission path via the air inside the cabinet 30B. The delay circuit 84 delays the electrical signal S1 so that the first speaker 10A vibrates in the same way at the timing when the vibration of the second speaker 20B is transmitted to the first speaker 10A via the air inside the cabinet 30B. The phase control unit 85B controls the phase of electrical signals S1 and 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 electrical signal S1 input to the first speaker 10A are in phase. Note that if the vibration transmitted through the transmission path is small, the delay circuit 84 may be omitted. Furthermore, if the volume of the cabinet 30B is small and the transmission path is short, a phase difference is less likely to occur, so the delay circuit 84 may be omitted. In particular, if the resonant frequency of the cabinet 30B is low (tens to hundreds of Hz), the delay circuit 84 can be omitted.

[0068] In this second embodiment of the speaker device 1B, as in the first embodiment of the speaker device 1A, it is possible to suppress the density of air in the internal space of the cabinet 30B and to suppress the movement of the center of gravity of the cabinet 30B.

[0069] Next, a speaker device 1C according to the third embodiment will be described. Figure 9 is a cross-sectional view of the speaker device 1C. Figure 10 is a side view of the speaker device 1C. The cabinet 30C of the speaker device 1C comprises a first cabinet 40C that holds the first speaker 10B, a second cabinet 50C that holds the second speaker 20A, and a connecting portion 60C that connects the first cabinet 40C and the second cabinet 50C. The first speaker 10B is positioned in the opposite direction to the first speaker 10A in the first embodiment.

[0070] The first surface 11 of the first speaker 10A is the sound-emitting surface, and the second surface 12 is the rear surface. The first surface 21 of the second speaker 20A is the rear surface, and the second surface 22 is the 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 exterior 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 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 panel 31C and an inner wall panel 42C facing each other in the Z direction. The first speaker 10B is mounted in an opening in the inner wall panel 42C. The rear of the first speaker 10B faces the front panel 31C in the Z direction. The second cabinet 50C includes a rear panel 32C and an inner wall panel 51C facing each other in the Z direction. The second speaker 20A is mounted in an opening in the rear panel 32C. The drive unit 3 of the second speaker 20A protrudes outward from the rear panel 32C in the Z direction.

[0072] A communication space J5 is formed between the first cabinet 40C and the second cabinet 50C, which communicates with the interior J1. The communication space J5 is formed between the interior wall panel 42C and the interior wall panel 51C. The communication space J5 communicates with the interior J1 through an opening 37C formed in the side panel 33C of the cabinet 30C.

[0073] The processing circuit 82 of the phase control device 80B applied to the speaker device 1C can generate in-phase electrical signals S1 and S2. The delay circuit 84 can delay electrical signal S1 with respect to electrical signal S2. In this third embodiment of the speaker device 1C, as in the second embodiment of the speaker device 1B, it is possible to suppress the density of air in the internal space of the cabinet 30C and to suppress the movement of the center of gravity of the cabinet 30C.

[0074] Figure 11 is a cross-sectional view of speaker device 1D according to the fourth embodiment. The cabinet 30D of speaker device 1D holds the first speaker 10A and the second speaker 20A.

[0075] The first surface 11 of the first speaker 10A is the sound-emitting surface, and the second surface 12 is the rear surface. The first surface 21 of the second speaker 20A is the rear surface, and the second surface 22 is the 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 exterior 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 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 in-phase electrical signals S1 and S2. In this fourth embodiment of the speaker device 1D, as in the speaker device 1A of the first embodiment, it is possible to suppress the density of air in the internal space of the cabinet 30D.

[0077] Figure 12 is a cross-sectional view of speaker device 1E according to the fifth embodiment. The cabinet 30E of speaker device 1E holds the first speaker 10A and the second speaker 20B.

[0078] The first surface 11 of the first speaker 10A is the sound-emitting surface, and the second surface 12 is the rear surface. The first surface 21 of the second speaker 20B is the sound-emitting surface, and the second surface 22 is the rear surface. The sound-emitting surface of the first speaker 10A is in contact with the space communicating with the room J1. The sound-emitting surface of the second speaker 20B is in contact with the space communicating 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. In 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 electrical signals S1 and S2 that are in opposite phase. In this fifth embodiment of the speaker device 1E, as in the first embodiment of the speaker device 1A, it is possible to suppress the density of air in the internal space of the cabinet 30E.

[0080] Figure 13 is a cross-sectional view of the speaker device 1F according to the sixth embodiment. Figure 14 is a side view of the speaker device 1F. Figure 15 is a view taken along the line BB in Figure 13. The differences between the speaker device 1F according to the sixth embodiment and the speaker device 1B according to the second embodiment are that the open space J6 is continuous in the X direction, and that in the Y direction, connecting portions 60F are provided on both sides of the second speaker 20B.

[0081] The speaker device 1F comprises a first speaker 10A, a second speaker 20B, and a cabinet 30F. The cabinet 30F has a first cabinet 40A that holds the first speaker 10A, a second cabinet 50B that holds the second speaker 20B, and a connecting part 60F that connects the first cabinet 40A and the second cabinet 50B.

[0082] In the speaker unit 1F cabinet 30F, openings 37F and 38F are provided in the side panels 33F and 34F facing each other in the X direction. An opening 37F is provided in the side panel 33F, and an opening 38F is provided in the side panel 34F. The open space J6 is formed in the X direction from opening 37F to opening 38F. The connecting portion 60F is formed in the Y direction between side panel 35F and side panel 36F.

[0083] In this sixth embodiment of the speaker device 1F, as in the second embodiment of the speaker device 1B, it is possible to suppress the density of air in the internal space of the cabinet 30F and to suppress the movement of the center of gravity of the cabinet 30F.

[0084] Next, the speaker device 1G according to the seventh embodiment will be described. Figure 16 is a front view of the speaker device 1G. Figure 17 is a view taken along the line CC in Figure 16. Figure 18 is a view taken along the line DD in Figure 16. The cross-sectional shape of the speaker device 1G shown in Figure 17 is the same as the cross-sectional shape of the speaker device 1B of the second embodiment shown in Figure 2. The cross-sectional shape of the speaker device 1G shown in Figure 18 is the cross-sectional shape shown in Figure 17 inverted vertically.

[0085] The speaker device 1G comprises a first speaker 10A, a second speaker 20B, and a cabinet 30G. The cabinet 30G has a first cabinet 40G that holds the first speaker 10A, a second cabinet 50G that holds the second speaker 20B, and a connecting part 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 be cylindrical. The side panel 33G is formed to surround axes Z1 and Z2.

[0087] The connecting portion 60G is formed in the Z direction between the first cabinet 40G and the second cabinet 50G. The internal space of the connecting 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 connecting portion 60G is fan-shaped.

[0088] An opening 37G is formed in the side panel 33G. An open space J7 communicating with the outdoor area J2 is formed on the rear side of the second speaker 20B. The open space J7 communicates with the outdoor area J2 through the opening 37G. The opening 37G and the connecting parts 60G are arranged alternately in the circumferential direction of the side panel 33G. The first cabinet 40G and the second cabinet 50G are connected, for example, by three connecting parts 60G.

[0089] In this seventh embodiment of the speaker device 1G, as in the second embodiment of the speaker device 1B, it is possible to suppress the density of air in the internal space of the cabinet 30G and to suppress the movement of the center of gravity of the cabinet 30G.

[0090] The cabinet 30G of the speaker device 1G has a circular shape. The speaker device 1G may be mounted in the central opening of the spare tire. For example, in the trunk of a vehicle, the speaker device 1G may be held in the spare tire, with the first surface 11 of the first speaker 10A communicating with the interior of the vehicle and the first surface 21 of the second speaker 20B communicating with the exterior of the vehicle.

[0091] Next, with reference to Figures 19 and 20, the sound distortion in the model of the first speaker 10A will be explained. Figure 19 is a schematic diagram showing the model of the first speaker 10A. The right side of the diagram is the positive direction, and the left side is the negative direction. The sound-emitting surface of the first speaker 10A is positioned in the positive direction, and the back is positioned in the negative direction.

[0092] Figure 20 is a graph showing sound distortion in the model of the first speaker 10A shown in Figure 19. The horizontal axis represents the electrical signal, and the vertical axis represents the displacement of the diaphragm 2. Graph G1 shown in Figure 20 shows the relationship between the electrical signal and the displacement of the diaphragm 2 in the model of the first speaker 10A. In a speaker, due to its structure, there is no symmetry in the displacement of the diaphragm 2 in the positive and negative directions with respect to the electrical signal. This is sound distortion, or second-order distortion.

[0093] Next, with reference to Figures 21 and 22, sound distortion in a model of speaker device 91 having a first speaker 10A and a second speaker 20A arranged in the same orientation will be described. Figure 21 is a schematic diagram showing a model of speaker device 91. In speaker device 91, the sound-emitting surface of the first speaker 10A is oriented in the positive direction, and the back surface is oriented in the negative direction. The sound-emitting surface of the second speaker 20A is oriented in the positive direction, and the back surface is oriented in the negative direction.

[0094] Figure 22 is a graph showing sound distortion in the speaker device 91 model shown in Figure 21. Graph G2 in Figure 22 shows the relationship between the electrical signal and the displacement of the diaphragm 2 in the second speaker 20A model. When the first speaker 10A and the second speaker 20A are placed in the same orientation and sound is output, similar distortion appears in the displacement of the diaphragm 2 of the first speaker 10A and the diaphragm 2 of the second speaker 20A.

[0095] Next, with reference to Figures 23 and 24, we will describe the sound distortion in a model of speaker device 92, which has a first speaker 10A and a second speaker 20B arranged in opposite directions. Figure 23 is a schematic diagram showing a model of speaker device 92. In speaker device 92, the sound-emitting surface of the first speaker 10A is oriented in the positive direction, and the back surface is oriented in the negative direction. The sound-emitting surface of the second speaker 20B is oriented in the negative direction, and the back surface is oriented in the positive direction.

[0096] Figure 24 is a graph showing sound distortion in the speaker device 92 model shown in Figure 23. Graph G3 in Figure 24 shows the relationship between the electrical signal and the displacement of the diaphragm 2 in the second speaker 20B model. The speaker device 92 outputs electrical signals S1 and S2 with 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 is distorted as shown in graph G3. Graph G3 is symmetrical with respect to the zero point in both the positive and negative directions. This results in third-order distortion, which has little impact on sound quality.

[0097] The embodiments described above are merely representative of the present disclosure, and the present disclosure is not limited to the embodiments described above. Various modifications and additions are possible without departing from the gist of the present disclosure.

[0098] In the embodiments described above, indoor J1 and outdoor J2 are illustrated as examples, but indoor J1 and outdoor J2 may be reversed. For example, in the first embodiment shown in Figure 1, the area indicated by reference numeral J1 may be the outdoor area and the area indicated by reference numeral J2 may be the indoor area. In this case, the speaker indicated by reference numeral 10A is the second speaker, and the speaker indicated by reference numeral 20A is the first speaker. In the second to seventh embodiments as well, indoor J1 and outdoor J2 may be reversed.

[0099] In speaker device 1A, the second surface 12 of the first speaker 10A may be the sound-emitting surface. In this case, the back of the first speaker 10A communicates with the room J1, while the sound-emitting surface does not communicate with the room J1. In 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 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. In speaker device 1A, the sound-emitting surfaces of the first speaker 10A and the second speaker 20A may be arranged facing each other.

[0100] In the above-described embodiment, the first speaker 10A and the second speaker 20A are supplied with sound signals in opposite phase, but it is also possible to supply sound signals other than those in opposite phase. In the above-described embodiment, the first speaker 10A and the second speaker 20B are supplied with sound signals in the same phase, but it is also possible to supply sound signals other than those in the same phase.

[0101] In the embodiment described above, 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 coaxial arrangement. The axis Z1 of the first speaker 10A and the axis Z2 of the second speaker are parallel, and when viewed from a direction along the axis Z1 of the first speaker 10A, the first speaker 10A and the second speaker 20A may overlap.

[0102] The axis Z1 of the first speaker 10A and the axis Z2 of the second speaker 20A do not have to be parallel. Axis Z1 may be inclined with respect to axis Z2.

[0103] In the embodiment described above, 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 unit, 86A, 86B... Acoustic system, J1... Indoor, J2... Outdoor, Z1... Axis, Z2... Axis.

Claims

1. A first speaker having a first surface that communicates with the interior of the vehicle and a second surface that does not communicate with the interior of the vehicle, A second speaker having a first surface that communicates with the outside of the vehicle and a second surface that does not communicate with the outside of the vehicle, A cabinet in which a closed space is formed by the boundary-forming surface, Equipped with, The second surface of the aforementioned first speaker is the rear surface. The second side of the aforementioned second speaker is the rear, An audio signal is supplied to the first speaker. The second surface of the first speaker and the second surface of the second speaker are positioned at the boundary facing the closed space, A speaker device in which the first speaker and the second speaker are arranged coaxially and in the same orientation.

2. A first speaker having a first surface that communicates with the interior of the vehicle and a second surface that does not communicate with the interior of the vehicle, A second speaker having a first surface that communicates with the outside of the vehicle and a second surface that does not communicate with the outside of the vehicle, A cabinet in which a closed space is formed by the boundary-forming surface, Equipped with, The second surface of the first speaker is the sound-emitting surface. The second surface of the second speaker is the sound-emitting surface. An audio signal is supplied to the first speaker. The second surface of the first speaker and the second surface of the second speaker are positioned at the boundary facing the closed space, A speaker device in which the first speaker and the second speaker are arranged coaxially and in the same orientation.

3. A speaker device according to any one of claims 1 to 2, The system includes a phase control unit that generates a first sound signal and a second sound signal, which are two sound signals with a phase difference, and supplies the first sound signal to the first speaker and the second sound signal to the second speaker. Sound system.

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