Speaker apparatus

Abstract

A speaker apparatus (2) comprises: a signal processing circuit that processes an input first audio signal, and generates a first output signal and a second output signal; a first speaker (10) that outputs a first sound (S1), which is based on the first output signal, in a first direction; a second speaker (20) that is positioned on a second direction side on the opposite side from the first direction with respect to the first speaker (10), and outputs a second sound (S2), which is based on the second output signal, in the second direction; and a sound absorbing material (31) that is positioned between the first speaker (10) and the second speaker (20). A first filter and a second filter of the signal processing circuit have filter characteristics for adjusting the phase and amplitude of input signals at each frequency so that the sound pressure of the sound based on the first audio signal at a second position (P2) decreases by a predetermined value or more with respect to the sound pressure of the sound based on the first audio signal at a first position (P1).

Description

Speaker device

[0001] The present disclosure relates to a speaker device.

[0002] Conventionally, a directional speaker that radiates sound in a specific direction and suppresses the sound pressure of the sound at positions in directions other than the specific direction is known.

[0003] For example, in Patent Document 1, a technique for realizing sound directivity is disclosed by using a first speaker and a second speaker that send out acoustic signals having opposite phases to each other, and delaying the time at which the second speaker sends out the acoustic signal according to the distance between the two speakers. In the technique described in Patent Document 1, in the sound pressure suppression range where it is not desired to hear the sound from the first speaker, the sound having the opposite phase sent out from the second speaker is superimposed on the sound from the first speaker to cancel out the sound from the first speaker.

[0004] Japanese Unexamined Patent Application Publication No. 2013 - 33104

[0005] In a directional speaker, it is important to reduce the sound pressure of the sound at a position where it is not desired to hear the target sound to enhance the directivity of the sound.

[0006] The present disclosure provides a speaker device capable of enhancing the directivity of sound.

[0007] A speaker device according to one aspect of the present disclosure comprises: a signal processing circuit that performs signal processing on an input first audio signal to generate a first output signal and a second output signal; a first speaker that outputs a first sound based on the first output signal in a first direction; a second speaker arranged on the side of the first speaker in a second direction opposite to the first direction, and that outputs a second sound based on the second output signal in the second direction; and a sound-absorbing material arranged between the first speaker and the second speaker and extending along a plane perpendicular to the first direction, wherein the signal processing circuit includes a first filter and a second filter that perform signal processing on signals in at least a portion of the frequency band of the first audio signal. The first output signal is generated based on the output of the first filter, and the second output signal is generated based on the output of the second filter. The first and second filters have filter characteristics that adjust the frequency-dependent phase and amplitude of signals in at least a portion of the frequency band of the first audio signal so that the sound pressure of the sound based on the first audio signal at the second position decreases by a predetermined value or more with respect to the sound pressure of the sound based on the first audio signal at the first position due to the overlap of the first and second sounds. The first position is located on the first side of the first speaker, and the second position is located on the second side of the first position.

[0008] A speaker device according to one aspect of the present disclosure includes: a signal processing circuit that performs signal processing on an input first audio signal to generate a first output signal and a second output signal, and performs signal processing on an input second audio signal to generate a third output signal and a fourth output signal; a first speaker that outputs a first sound based on the first output signal and the fourth output signal in a first direction; and a second speaker that is arranged on the second direction side opposite to the first direction relative to the first speaker and outputs a second sound based on the second output signal and the third output signal in the second direction, wherein the signal processing circuit includes a first filter and a second filter that perform signal processing on signals in at least a portion of the frequency band of the first audio signal, and a third filter and a fourth filter that perform signal processing on signals in at least a portion of the frequency band of the second audio signal, wherein the first output signal is generated based on the output of the first filter, the second output signal is generated based on the output of the second filter, the third output signal is generated based on the output of the third filter, and the fourth output signal is The first and second filters are generated based on the output of the fourth filter, and each filter has filter characteristics that adjust the frequency-dependent phase and amplitude of the signal in at least a portion of the frequency band of the first audio signal so that the sound pressure of the sound based on the first audio signal at the second position decreases by a predetermined value or more with respect to the sound pressure of the sound based on the first audio signal at the first position due to the overlap of the first and second sounds. The third and fourth filters have filter characteristics that adjust the frequency-dependent phase and amplitude of the signal in at least a portion of the frequency band of the second audio signal so that the sound pressure of the sound based on the second audio signal at the fourth position decreases by a predetermined value or more with respect to the sound pressure of the sound based on the second audio signal at the third position due to the overlap of the first and second sounds. The first position is located on the first side of the first speaker, the second position is located on the second side of the first position, the third position is located on the second side of the second speaker, and the fourth position is located on the first side of the third position.

[0009] According to this disclosure, a speaker device capable of enhancing sound directivity can be provided.

[0010] Figure 1 is a plan view showing an example of the external appearance of a speaker device according to an embodiment. Figure 2 is a block diagram showing an example of the functional configuration of a speaker device according to an embodiment. Figure 3 is a diagram illustrating a method for designing the filter characteristics of the first FIR filter, second FIR filter, third FIR filter, and fourth FIR filter. Figure 4 is a flowchart showing an example of a method for designing the filter characteristics of the first FIR filter, second FIR filter, third FIR filter, and fourth FIR filter. Figure 5 is a plan view showing an example of the external appearance of a speaker device according to Modification 1 of the embodiment. Figure 6 is a plan view showing an example of the external appearance of a speaker device according to Modification 2 of the embodiment. Figure 7 is a plan view showing an example of the external appearance of a speaker device according to Modification 3 of the embodiment. Figure 8 is a block diagram showing an example of the functional configuration of a speaker device according to Modification 4 of the embodiment.

[0011] (Summary of this disclosure) Below is an overview of this disclosure, including an example of a speaker device related to this disclosure.

[0012] A speaker device according to a first aspect of the present disclosure comprises: a signal processing circuit that performs signal processing on an input first audio signal to generate a first output signal and a second output signal; a first speaker that outputs a first sound based on the first output signal in a first direction; a second speaker positioned on the side of the first speaker in a second direction opposite to the first direction, and that outputs a second sound based on the second output signal in the second direction; and a sound-absorbing material positioned between the first speaker and the second speaker and extending along a plane perpendicular to the first direction, wherein the signal processing circuit comprises a first filter and a second filter that perform signal processing on signals in at least a portion of the frequency band of the first audio signal. The device has a first output signal generated based on the output of the first filter, and a second output signal generated based on the output of the second filter. The first and second filters have filter characteristics that adjust the frequency-dependent phase and amplitude of signals in at least a portion of the frequency band of the first audio signal so that the sound pressure of the sound based on the first audio signal at the second position decreases by a predetermined value or more with respect to the sound pressure of the sound based on the first audio signal at the first position due to the overlap of the first and second sounds. The first position is located on the first side of the first speaker, and the second position is located on the second side of the first position.

[0013] This enhances the directivity of the sound. Specifically, the first sound is a sound based on the output of the first filter, and the second sound is a sound based on the output of the second filter. Therefore, due to signal processing by the first and second filters, the sound pressure of the sound based on the first audio signal at the second position is reduced by a predetermined value or more compared to the sound pressure of the sound based on the first audio signal at the first position, as the first and second sounds overlap. For example, if a sound with the opposite phase is output from the second speaker to cancel out the sound based on the first audio signal, as in Patent Document 1, the way the sound propagates changes depending on the frequency, making it impossible to cancel out the sound based on the first audio signal over a wide frequency range at the second position. On the other hand, according to this embodiment, the phase and amplitude of the first audio signal are adjusted for each frequency by the first and second filters. Therefore, compared to the case where a sound with the opposite phase is output to cancel out the sound based on the first audio signal, the sound based on the first audio signal is canceled out over a wide frequency range at the second position, and the amount of cancellation can also be increased. Therefore, the directivity of sound based on the first audio signal can be enhanced. Furthermore, since sound-absorbing material is placed between the first speaker and the second speaker, the sound-absorbing material can absorb the first sound that tries to wrap around to the second direction from the first speaker. As a result, the sound based on the first audio signal can be reduced in the area to the second direction from the first speaker, and the directivity of sound based on the first audio signal can be enhanced.

[0014] Furthermore, for example, a speaker device according to a second aspect of the present disclosure is a speaker device according to a first aspect, further comprising at least one of a first horn that emits the first sound output from the first speaker in a first direction, and a second horn that emits the second sound output from the second speaker in a second direction.

[0015] This allows the range over which the sound based on the first audio signal is heard to be controlled by the first sound.

[0016] Furthermore, for example, a speaker device according to a third aspect of the present disclosure is a speaker device according to the first or second aspect, further comprising at least one of a first diffuser for diffusing the first sound output from the first speaker and a second diffuser for diffusing the second sound output from the second speaker.

[0017] This allows the range over which the sound based on the first audio signal is heard to be controlled by the first sound.

[0018] Furthermore, for example, a speaker device according to a fourth aspect of the present disclosure is a speaker device according to a first aspect, further comprising at least one of a first horn that emits the first sound output from the first speaker in a first direction and a second horn that emits the second sound output from the second speaker in a second direction, and at least one of a first diffuser that diffuses the first sound output from the first speaker and a second diffuser that diffuses the second sound output from the second speaker.

[0019] This allows the range over which the sound based on the first audio signal is heard to be controlled by the first sound.

[0020] Furthermore, for example, a speaker device according to a fifth aspect of the present disclosure is a speaker device according to any one of the first to fourth aspects, further comprising a sound-reflecting material disposed between the sound-absorbing material and the second speaker, and extending along a plane perpendicular to the first direction.

[0021] As a result, the sound reflecting material reflects the components of the first sound incident on the sound absorbing material that were not absorbed by the sound absorbing material. This reduces the sound based on the first audio signal in the area on the second direction side of the first speaker, thereby improving the directivity of the sound based on the first audio signal.

[0022] Furthermore, for example, a speaker device according to a sixth aspect of the present disclosure is a speaker device according to any one of the first to fifth aspects, wherein the signal processing circuit performs signal processing on an input second audio signal to generate a third output signal and a fourth output signal, the first speaker outputs the first sound based on the first output signal and the fourth output signal, the second speaker outputs the second sound based on the second output signal and the third output signal, the signal processing circuit has a third filter and a fourth filter that perform signal processing on signals in at least a portion of the frequency band of the second audio signal, and the third output signal is the The third and fourth filters are generated based on the output of the third filter, and the fourth output signal is generated based on the output of the fourth filter. The third and fourth filters have filter characteristics that adjust the frequency-dependent phase and amplitude of the signals in at least a portion of the frequency band of the second audio signal so that the sound pressure of the sound based on the second audio signal at the fourth position decreases by a predetermined value or more with respect to the sound pressure of the sound based on the second audio signal at the third position due to the overlap of the first and second sounds. The third position is located on the second direction side of the second speaker, and the fourth position is located on the first direction side of the third position.

[0023] As a result, signal processing by the third and fourth filters causes the sound pressure of the sound based on the second audio signal at the fourth position to decrease by a predetermined value or more compared to the sound pressure of the sound based on the second audio signal at the third position, due to the overlap of the first and second sounds. In addition, the phase and amplitude of the second audio signal are adjusted for each frequency by the third and fourth filters. Therefore, compared to outputting a sound with the opposite phase to cancel out the sound based on the second audio signal, the sound based on the second audio signal is canceled out over a wider frequency range at the fourth position, and the amount of cancellation can also be increased. Therefore, the directivity of the sound based on the second audio signal can be improved.

[0024] Furthermore, in the speaker device according to this embodiment, the directivity of sound based on the first audio signal and the directivity of sound based on the second audio signal are realized by two speakers, the first speaker and the second speaker. Therefore, there is no need to provide a separate speaker for outputting a cancellation sound to cancel out the sound based on the first audio signal and the sound based on the second audio signal, and the configuration of the speaker device can be simplified and miniaturized.

[0025] Furthermore, for example, a speaker device according to a seventh aspect of the present disclosure includes: a signal processing circuit that performs signal processing on an input first audio signal to generate a first output signal and a second output signal, and performs signal processing on an input second audio signal to generate a third output signal and a fourth output signal; a first speaker that outputs a first sound based on the first output signal and the fourth output signal in a first direction; and a second speaker that is arranged on the second direction side opposite to the first direction relative to the first speaker and outputs a second sound based on the second output signal and the third output signal in the second direction, wherein the signal processing circuit includes a first filter and a second filter that perform signal processing on signals in at least a portion of the frequency band of the first audio signal, and a third filter and a fourth filter that perform signal processing on signals in at least a portion of the frequency band of the second audio signal, wherein the first output signal is generated based on the output of the first filter, the second output signal is generated based on the output of the second filter, the third output signal is generated based on the output of the third filter, and the fourth output signal The signal is generated based on the output of the fourth filter, and the first and second filters have filter characteristics that adjust the frequency-dependent phase and amplitude of the signal in at least a portion of the frequency band of the first audio signal so that the sound pressure of the sound based on the first audio signal at the second position decreases by a predetermined value or more with respect to the sound pressure of the sound based on the first audio signal at the first position due to the overlap of the first and second sounds, and the third and fourth filters have filter characteristics that adjust the frequency-dependent phase and amplitude of the signal in at least a portion of the frequency band of the second audio signal so that the sound pressure of the sound based on the second audio signal at the fourth position decreases by a predetermined value or more with respect to the sound pressure of the sound based on the second audio signal at the third position due to the overlap of the first and second sounds, and the first position is located on the first direction side of the first speaker, the second position is located on the second direction side of the first position, the third position is located on the second direction side of the second speaker, and the fourth position is located on the first direction side of the third position.

[0026] This enhances the directivity of the sound. Specifically, signal processing by the first and second filters reduces the sound pressure of the sound based on the first audio signal at the second position by a predetermined value or more compared to the sound pressure of the sound based on the first audio signal at the first position, due to the overlap of the first and second sounds. In addition, the phase and amplitude of the first audio signal are adjusted for each frequency by the first and second filters. As a result, the sound based on the first audio signal is canceled out over a wider range of frequencies at the second position, and the amount of cancellation can also be increased, compared to outputting a sound with the opposite phase to cancel out the sound based on the first audio signal. Therefore, the directivity of the sound based on the first audio signal can be enhanced. Furthermore, signal processing by the third and fourth filters reduces the sound pressure of the sound based on the second audio signal at the fourth position by a predetermined value or more compared to the sound pressure of the sound based on the second audio signal at the third position, due to the overlap of the first and second sounds. Furthermore, the phase and amplitude of the second audio signal are adjusted for each frequency by the third and fourth filters. As a result, at the fourth position, the sound based on the second audio signal is canceled out over a wider frequency range, and the amount of cancellation can also be increased, compared to outputting a sound with the opposite phase to cancel out the sound based on the second audio signal. Therefore, the directivity of the sound based on the second audio signal can be improved.

[0027] Furthermore, in the speaker device according to this embodiment, the directivity of sound based on the first audio signal and the directivity of sound based on the second audio signal are realized by two speakers, the first speaker and the second speaker. Therefore, there is no need to provide a separate speaker for outputting a cancellation sound to cancel out the sound based on the first audio signal and the sound based on the second audio signal, and the configuration of the speaker device can be simplified and miniaturized.

[0028] Furthermore, for example, a speaker device according to the eighth aspect of the present disclosure is a speaker device according to the seventh aspect, further comprising at least one of a first horn that emits the first sound output from the first speaker in the first direction, and a second horn that emits the second sound output from the second speaker in the second direction.

[0029] This allows the range in which the sound based on the first audio signal is heard to be controlled by the first sound, and the range in which the sound based on the second audio signal is heard to be controlled by the second sound.

[0030] Furthermore, for example, a speaker device according to the ninth aspect of this disclosure is a speaker device according to the seventh or eighth aspect, further comprising at least one of a first diffuser for diffusing the first sound output from the first speaker and a second diffuser for diffusing the second sound output from the second speaker.

[0031] This allows the range in which the sound based on the first audio signal is heard to be controlled by the first sound, and the range in which the sound based on the second audio signal is heard to be controlled by the second sound.

[0032] Furthermore, for example, a speaker device according to a tenth aspect of the present disclosure is a speaker device according to a seventh aspect, further comprising: at least one of a first horn that emits the first sound output from the first speaker in a first direction and a second horn that emits the second sound output from the second speaker in a second direction; and at least one of a first diffuser that diffuses the first sound output from the first speaker and a second diffuser that diffuses the second sound output from the second speaker.

[0033] This allows the range in which the sound based on the first audio signal is heard to be controlled by the first sound, and the range in which the sound based on the second audio signal is heard to be controlled by the second sound.

[0034] The embodiments will be described below with reference to the drawings as appropriate. However, unnecessarily detailed explanations may be omitted. For example, detailed explanations of already well-known matters and redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding for those skilled in the art.

[0035] The inventors of this application provide the accompanying drawings and the following description so that those skilled in the art may fully understand the disclosure, and do not intend to limit the subject matter described in the claims.

[0036] In the following embodiments, for the sake of explanation, the front-to-back direction is aligned with the X-axis direction, the left-to-right direction (lateral direction) is aligned with the Y-axis direction, and the up-to-down direction is aligned with the Z-axis direction. However, these alignments do not limit the orientation of the speaker device during manufacturing or use according to this disclosure. The X-axis, Y-axis, and Z-axis represent the three axes of a three-dimensional Cartesian coordinate system. In the following description, for example, the X-axis positive direction refers to the direction of the arrow on the X-axis, and the X-axis negative direction refers to the direction opposite to the X-axis positive direction. The same applies to the Y-axis and Z-axis directions. The X-axis positive direction is an example of a first direction, and the X-axis negative direction is an example of a second direction, which is the opposite direction to the first direction. Furthermore, each figure is a schematic diagram and is not necessarily a strictly accurate representation. Therefore, the scale and other aspects in each figure do not necessarily match.

[0037] Furthermore, in this specification, ordinal numbers such as "first," "second," etc., do not mean the number or order of components unless otherwise specified, but are used to avoid confusion and to distinguish similar components.

[0038] (Embodiment) The speaker device according to this embodiment will be described below.

[0039] [Configuration] First, the configuration of the speaker device according to this embodiment will be described using Figures 1 and 2.

[0040] Figure 1 is a plan view showing an example of the external appearance of the speaker device 1 according to this embodiment. Figure 2 is a block diagram showing an example of the functional configuration of the speaker device 1 according to this embodiment. Figure 1 shows the external appearance of the speaker device 1 as viewed from above (Z-axis positive direction). In addition, in Figure 1 and the plan view showing the external appearance of the speaker device described later, the first diaphragm 10a and the second diaphragm 20a housed inside the first housing 10b and the second housing 20b, respectively, are shown by dashed lines.

[0041] As shown in Figure 1, the speaker device 1 comprises a first speaker 10 and a second speaker 20. In the example shown in Figure 1, the first speaker 10 and the second speaker 20 are aligned along the positive X-axis direction.

[0042] The speaker device 1 is a directional speaker that realizes the directivity of sound based on the input voice signal in one or more areas. The speaker device 1 includes two speakers, that is, a first speaker 10 and a second speaker 20, and has a configuration that is easy to miniaturize while having directivity. The speaker device 1 is assumed to be installed, for example, in a shared space in a house, an office, a commercial facility, or the like.

[0043] As shown in FIG. 2, a first voice signal and a second voice signal are input to the speaker device 1, and the speaker device 1 outputs a sound based on the first voice signal and a sound based on the second voice signal. The speaker device 1 can output the sound based on the first voice signal and the sound based on the second voice signal simultaneously. Also, when one of the first voice signal and the second voice signal is input, the speaker device 1 outputs the sound based on the one.

[0044] As shown in FIG. 1, the first speaker 10 outputs a first sound S1 in the +X axis direction. The first speaker 10 includes a first diaphragm 10a that is part of the speaker unit, and a first housing 10b that houses the speaker unit. The speaker unit of the first speaker 10 includes, for example, a support member that supports the first diaphragm 10a, a magnet, a voice coil, and other components not shown, in addition to the first diaphragm 10a. The first diaphragm 10a is directed in the +X axis direction and is fixed to the first housing 10b at the end on the +X axis direction side of the first housing 10b. The first speaker 10 outputs the first sound S1 in the +X axis direction by vibrating the first diaphragm 10a.

[0045] The first housing 10b is, for example, a cylindrical housing having the +X axis direction as the axial direction. An opening for installing the first diaphragm 10a is provided at the end on the +X axis direction side of the first housing 10b, and the opening is blocked by the first diaphragm 10a. Also, the end on the -X axis direction side of the first housing 10b is blocked by a plate-like member. The outer shape of the first housing 10b is, for example, cylindrical or prismatic.

[0046] The second speaker 20 outputs the second sound S2 in the negative X-axis direction. The second speaker 20 includes a second diaphragm 20a that is part of the speaker unit, and a second housing 20b that houses the speaker unit. The speaker unit of the second speaker 20 includes, for example, in addition to the second diaphragm 20a, components such as a support member that supports the second diaphragm 20a, a magnet, and a voice coil (not shown). The second diaphragm 20a is oriented in the negative X-axis direction and is fixed to the second housing 20b at the end of the second housing 20b on the negative X-axis side. The second speaker 20 outputs the second sound S2 in the negative X-axis direction by vibrating the second diaphragm 20a. Also, the first diaphragm 10a and the second diaphragm 20a are arranged coaxially with an axis parallel to the positive X-axis direction. Therefore, when viewed from the positive X-axis direction side, the center of the first diaphragm 10a and the center of the second diaphragm 20a coincide.

[0047] The second housing 20b is, for example, a cylindrical housing with the positive X-axis direction as the axial direction. An opening for installing the second diaphragm 20a is provided at the end of the second housing 20b on the negative X-axis side, and the opening is blocked by the second diaphragm 20a. Also, the end of the second housing 20b on the positive X-axis side is blocked by a plate-like member. The outer shape of the second housing 20b is, for example, cylindrical or prismatic.

[0048] In the example shown in FIG. 1, the first speaker 10 and the second speaker 20 are fixed by being connected with a connecting rod. Note that the method of fixing the first speaker 10 and the second speaker 20 is not particularly limited. For example, the first speaker 10 and the second speaker 20 may be fixed by directly connecting the first housing 10b and the second housing 20b.

[0049] Although details will be described later, the first sound S1 includes the sound indicated by the first audio signal, and the second sound S2 includes the sound indicated by the second audio signal. Also, the first sound S1 further includes a cancellation sound that can cancel the sound indicated by the second audio signal by overlapping with the second sound S2. Also, the second sound S2 includes a cancellation sound that can cancel the sound indicated by the first audio signal by overlapping with the first sound S1.

[0050] As shown in Figure 2, the speaker device 1 further comprises a signal processing circuit 50, input interfaces (I / F) 70a and 70b, a processor 71, a memory 72, and a communication interface (I / F) 73. The signal processing circuit 50, input interfaces 70a and 70b, processor 71, memory 72, and communication interface 73 are mounted, for example, on one or more circuit boards not shown in Figure 1. The one or more circuit boards are arranged, for example, in the first housing 10b or the second housing 20b, but may also be arranged in another housing not shown in Figure 1.

[0051] The signal processing circuit 50 performs signal processing on the first audio signal input to the signal processing circuit 50 via the input interface 70a to generate a first output signal OUT1 and a second output signal OUT2. The signal processing circuit 50 also performs signal processing on the second audio signal input to the signal processing circuit 50 via the input interface 70b to generate a third output signal OUT3 and a fourth output signal OUT4. The first audio signal and the second audio signal are audio signals input from an audio signal output device such as an external sound source player. The first speaker 10 outputs a first tone S1 based on the first output signal OUT1 and the fourth output signal OUT4 generated by the signal processing circuit 50. The second speaker 20 outputs a second tone S2 based on the second output signal OUT2 and the third output signal OUT3 generated by the signal processing circuit 50. The signal processing circuit 50 may also receive the first audio signal and the second audio signal based on audio data stored in the memory 72.

[0052] The signal processing circuit 50 includes a first FIR (Finite Impulse Response) filter 51, a second FIR filter 52, a third FIR filter 53, a fourth FIR filter 54, filters 61a and 61b, and adders 62a and 62b. The first FIR filter 51 is an example of a first filter. The second FIR filter 52 is an example of a second filter. The third FIR filter 53 is an example of a third filter. The fourth FIR filter 54 is an example of a fourth filter.

[0053] The first FIR filter 51 and the second FIR filter 52 perform signal processing on the first audio signal after processing by filter 61a. The third FIR filter 53 and the fourth FIR filter 54 perform signal processing on the second audio signal after processing by filter 61b. The first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54 are adaptive filters set to filter characteristics determined by adaptive filter design. The first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54 adjust the phase and amplitude of the input signal for each frequency. Specifically, the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54 apply (multiply) control coefficients for the phase and amplitude of the input signal to the input signal and output the result. The filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54 are determined, for example, by an information processing device 100, which is a separate device from the speaker device 1. The information processing device 100 may be included in the speaker device 1. Details of the filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54 will be described later.

[0054] The first audio signal is input to filter 61a via the input interface 70a. The second audio signal is input to filter 61b via the input interface 70b. Filters 61a and 61b are filters for adjusting the sound quality of the input audio signal. Note that the signal processing circuit 50 does not necessarily have filters 61a and 61b. In other words, the first audio signal may be directly input to the first FIR filter 51 and the second FIR filter 52 via the input interface 70a, and the second audio signal may be directly input to the third FIR filter 53 and the fourth FIR filter 54 via the input interface 70b.

[0055] In the signal processing circuit 50, the first output signal OUT1 is generated based on the output of the first FIR filter 51. The second output signal OUT2 is generated based on the output of the second FIR filter 52. The third output signal OUT3 is generated based on the output of the third FIR filter 53. The fourth output signal OUT4 is generated based on the output of the fourth FIR filter 54. In the example shown in Figure 2, the first output signal OUT1 is the output of the first FIR filter 51. The second output signal OUT2 is the output of the second FIR filter 52. The third output signal OUT3 is the output of the third FIR filter 53. The fourth output signal OUT4 is the output of the fourth FIR filter 54.

[0056] Adder 62a adds the first output signal OUT1 and the fourth output signal OUT4, and outputs the added signal to the first speaker 10. The first speaker 10 outputs the first tone S1 based on the output of adder 62a, which is a signal based on the first output signal OUT1 and the fourth output signal OUT4. Adder 62b adds the second output signal OUT2 and the third output signal OUT3, and outputs the added signal to the second speaker 20. The second speaker 20 outputs the second tone S2 based on the output of adder 62b, which is a signal based on the second output signal OUT2 and the third output signal OUT3.

[0057] As shown in Figure 1, the first speaker 10 emits the first sound S1 and the second speaker 20 emits the second sound S2. As a result, the first sound S1 and the second sound S2 overlap at each of the first position P1, second position P2, third position P3, and fourth position P4, and the sound transmitted by the speaker device 1 is heard as a composite sound of the first sound S1 and the second sound S2.

[0058] In speaker device 1, the sound pressure of the sound based on the first audio signal at the second position P2 decreases by a predetermined value or more compared to the sound pressure of the sound based on the first audio signal at the first position P1, due to the overlap of the first sound S1 and the second sound S2. Also, in speaker device 1, the sound pressure of the sound based on the second audio signal at the fourth position P4 decreases by a predetermined value or more compared to the sound pressure of the sound based on the second audio signal at the third position P3, due to the overlap of the first sound S1 and the second sound S2.

[0059] The first position P1 is located on the positive X-axis side of the first speaker 10. In the example shown in Figure 1, the first position P1 is located directly in front of the first speaker 10 in the positive X-axis direction. The second position P2 is located on the negative X-axis side of the first position P1. In the example shown in Figure 1, the second position P2 is located on the negative X-axis side of the second speaker 20, and more specifically, directly in front of the second speaker 20 in the negative X-axis direction. The third position P3 is located on the negative X-axis side of the second speaker 20. In the example shown in Figure 1, the third position P3 is located directly in front of the second speaker 20 in the negative X-axis direction. The fourth position P4 is located on the positive X-axis side of the third position P3. In the example shown in Figure 1, the fourth position P4 is located on the positive X-axis side of the first speaker 10, and more specifically, directly in front of the first speaker 10 in the positive X-axis direction.

[0060] Furthermore, in the example shown in Figure 1, the first position P1 and the fourth position P4 are the same position. Also, the second position P2 and the third position P3 are the same position. However, the first position P1 and the fourth position P4 may be different positions. Also, the second position P2 and the third position P3 may be different positions. Furthermore, the first position P1 may be located on the positive X-axis side of the first speaker 10, but not directly in front of the first speaker 10 in the positive X-axis direction. Furthermore, the second position P2 may be located on the negative X-axis side of the first position P1, but not directly in front of the second speaker 20 in the negative X-axis direction. Furthermore, the third position P3 may be located on the negative X-axis side of the second speaker 20, but not directly in front of the second speaker 20 in the negative X-axis direction. Furthermore, the fourth position may be located on the positive X-axis side of the third position P3, but not directly in front of the first speaker 10 in the positive X-axis direction.

[0061] Input interface 70a receives a first audio signal from an external source and inputs the received first audio signal to the signal processing circuit 50. Input interface 70b receives a second audio signal from an external source and inputs the received second audio signal to the signal processing circuit 50. Input interfaces 70a and 70b are, for example, analog audio input interfaces or optical digital input interfaces, but may also be Bluetooth® interfaces, USB (Universal Serial Bus) interfaces, or Wi-Fi® interfaces. Furthermore, if the first audio signal and the second audio signal are analog signals, AD (Analog to Digital) conversion is performed in the signal processing circuit 50 or input interfaces 70a and 70b. The signals processed and output by the signal processing circuit 50 undergo DA (Digital to Analog) conversion before being input to the first speaker 10 and the second speaker 20.

[0062] The processor 71 is a processing circuit that performs various information processing for the speaker device 1 to emit sound. The processor 71 realizes various functions by executing programs stored in the memory 72.

[0063] The processor 71 stores information received from an external information processing device 100, etc., via a communication interface 73, for example, in the memory 72. The information received by the processor 71 includes, for example, the filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, the fourth FIR filter 54, and filters 61a and 61b. The processor 71 may also update the filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, the fourth FIR filter 54, and filters 61a and 61b stored in the memory 72 based on the information received from the external information processing device 100, etc. For example, when the power to the speaker device 1 is turned on, the processor 71 reads the filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, the fourth FIR filter 54, and filters 61a and 61b from the memory 72 and sets them for each filter.

[0064] Memory 72 is a storage device that stores the program executed by the processor 71 and the data necessary for the processing performed by the processor 71. Memory 72 stores, for example, the filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, the fourth FIR filter 54, and filters 61a and 61b. Memory 72 is composed of a storage device that includes, for example, semiconductor memory such as flash memory. The storage device may also include an HDD (Hard Disk Drive) or the like.

[0065] The communication interface 73 is a communication circuit for communicating with external devices such as the information processing device 100. The speaker device 1 is connected to the external devices such as the information processing device 100 via the communication interface 73. Communication via the communication interface 73 may be wireless or wired. There are no particular restrictions on the communication standard for communication via the communication interface 73. The speaker device 1 does not need to be constantly connected to the external devices such as the information processing device 100, and may be connected to external devices only when communication is necessary, such as when determining the filter characteristics of the first FIR filter 51, second FIR filter 52, third FIR filter 53, and fourth FIR filter 54 as described later.

[0066] The information processing device 100 is a computer for determining the filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54. The information processing device 100 includes, for example, a processor, memory, a communication interface, and a user interface. The information processing device 100 determines the filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54 by having the processor execute a program stored in memory. The filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54 determined by the information processing device 100 are transmitted to the speaker device 1.

[0067] [Filter Characteristics of FIR Filters] Here, we will describe in detail the filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54.

[0068] The first FIR filter 51 and the second FIR filter 52 are adaptive filters set at the first position P1 and the second position P2 so that the sound based on the first audio signal transmitted by the speaker device 1 has desired acoustic characteristics. The first FIR filter 51 and the second FIR filter 52 have filter characteristics that adjust the phase and amplitude of the input signal for each frequency so that the sound pressure of the sound based on the first audio signal at the second position P2 decreases by a predetermined value or more from the sound pressure of the sound based on the first audio signal at the first position P1 as the first sound S1 and the second sound S2 overlap. The third FIR filter 53 and the fourth FIR filter 54 are adaptive filters set at the third position P3 and the fourth position P4 so that the sound based on the second audio signal transmitted by the speaker device 1 has desired acoustic characteristics. The third FIR filter 53 and the fourth FIR filter 54 have filter characteristics that adjust the frequency-specific phase and amplitude of the input signal so that the sound pressure of the sound based on the second audio signal at the fourth position P4 decreases by a predetermined value or more relative to the sound pressure of the sound based on the second audio signal at the third position P3 as the first sound S1 and the second sound S2 overlap.

[0069] The filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54 include frequency-dependent phase characteristics and amplitude characteristics, specifically, frequency-dependent phase and amplitude control coefficients. Such filter characteristics can be achieved by the adaptive filter design described later.

[0070] The filter characteristics of the first FIR filter 51 and the second FIR filter 52 are set so that the sound based on the first audio signal in the synthesized sound of the first tone S1 and the second tone S2 has a desired amplitude-frequency characteristic at the first position P1 and the second position P2, respectively. Specifically, in designing the filter characteristics of the first FIR filter 51 and the second FIR filter 52, the target amplitude-frequency characteristic at the second position P2 is set lower by a predetermined sound pressure amount than the target amplitude-frequency characteristic at the first position P1. As a result, at the second position P2, the sound based on the first audio signal in the second tone S2 is nearly out of phase with respect to the sound based on the first audio signal in the first tone S1. Consequently, with respect to the sound based on the first audio signal, the sound pressure at the second position P2 is lower than the sound pressure at the first position P1. Furthermore, the first FIR filter 51 has a filter characteristic that increases the amplitude of the low-frequency range of the input signal, for example. This makes it possible to compensate for the low-frequency sound pressure of the sound based on the first audio signal, which may decrease in sound pressure at the first position P1 due to the overlap of the first tone S1 and the second tone S2. The low-frequency range is, for example, a predetermined frequency range among frequencies below 1 kHz.

[0071] The filter characteristics of the third FIR filter 53 and the fourth FIR filter 54 are set so that the sound based on the second audio signal in the synthesized sound of the first tone S1 and the second tone S2 has a desired amplitude-frequency characteristic at the third position P3 and the fourth position P4, respectively. Specifically, in designing the filter characteristics of the third FIR filter 53 and the fourth FIR filter 54, the target amplitude-frequency characteristic at the fourth position P4 is set lower by a predetermined sound pressure amount than the target amplitude-frequency characteristic at the third position P3. As a result, at the fourth position P4, the sound based on the second audio signal in the first tone S1 is nearly out of phase with respect to the sound based on the second audio signal in the second tone S2. Consequently, with respect to the sound based on the second audio signal, the sound pressure at the third position P3 is lower than the sound pressure at the fourth position P4. Furthermore, the third FIR filter 53 has a filter characteristic that increases the amplitude of the input signal in the low-frequency range, for example. This makes it possible to compensate for the low-frequency sound pressure of the sound based on the second audio signal, which may decrease in sound pressure at the third position P3 due to the overlap of the first tone S1 and the second tone S2. The low-frequency range is, for example, a predetermined frequency range among frequencies below 1 kHz.

[0072] [Method for Designing the Filter Characteristics of FIR Filters] Next, with reference to Figures 3 and 4, the method by which the information processing device 100 determines the filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54 will be described. Figure 3 is a diagram illustrating the method for designing the filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54. Figure 4 is a flowchart illustrating an example of the method for designing the filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54. Figure 4 shows the process by which the information processing device 100 performs adaptive filter design.

[0073] First, we will explain the design method for the filter characteristics of the first FIR filter 51 and the second FIR filter 52.

[0074] The information processing device 100 determines the filter characteristics of the first FIR filter 51 and the second FIR filter 52 using, for example, a microphone 111 located at a first position P1 and a microphone 112 located at a second position P2. Specifically, the information processing device 100 first transmits a test audio signal to the speaker device 1 (step S11). The speaker device 1 receives the transmitted test audio signal via the input interface 70a. The received test audio signal is processed by the signal processing circuit 50 and output to the first speaker 10 and the second speaker 20, and test sounds based on the test audio signal are output from the first speaker 10 and the second speaker 20. At this time, the initial values ​​of the filter characteristics of the first FIR filter 51 and the second FIR filter 52 are set arbitrarily by, for example, the user.

[0075] Next, the test sound transmitted from the speaker device 1 is picked up by microphones 111 and 112, and the information processing device 100 acquires the results of the test sound at the first position P1 and the second position P2, respectively, as picked up by microphones 111 and 112 (step S12). Then, based on the results of the test sound acquired in step S12, the information processing device 100 determines the filter characteristics of the first FIR filter 51 and the second FIR filter 52 (step S13). Specifically, the user has set the target amplitude-frequency characteristics of the test sound at the first position P1 and the second position P2 in the information processing device 100. The information processing device 100 determines the filter characteristics of the first FIR filter 51 and the second FIR filter 52 so that the amplitude-frequency characteristics of the test sound results acquired at the first position P1 and the second position P2 asymptotically approach the target amplitude-frequency characteristics of the first position P1 and the second position P2, respectively. For determining the filter characteristics in this case, known algorithms such as the LMS (Least Mean Square) algorithm (least squares method) are used.

[0076] For example, the amplitude-frequency characteristics of the target test sound at the first position P1 are set to be the same as the amplitude-frequency characteristics of the test audio signal to be transmitted. Also, for example, the amplitude-frequency characteristics of the target test sound at the second position P2 are set to be the same as the amplitude-frequency characteristics of the target test sound at the first position P1, but lowered by a predetermined sound pressure. The average value of the predetermined sound pressure in the frequency range in which the adaptive filter design is performed is, for example, 10 dB or more and 30 dB or less. Note that these amplitude-frequency characteristics of the target test sound at the first position P1 and the second position P2 are examples, and the ideal amplitude-frequency characteristics at the first position P1 and the second position P2 will be set according to the acoustic design, etc.

[0077] Next, the information processing device 100 determines whether the termination conditions for the adaptive filter design are met (step S14). The termination conditions are, for example, whether the difference between the amplitude-frequency characteristics of the acquired test sound results at the first position P1 and the second position P2 and the amplitude-frequency characteristics of the target test sound for each is below a threshold.

[0078] If the difference exceeds a threshold, the information processing device 100 determines that the termination condition is not met (No in step S14), sets the filter characteristics of the first FIR filter 51 and the second FIR filter 52 determined above to the speaker device 1, and repeats the process from step S11. As the process from step S11 to step S13 is repeated, the filter characteristics of the first FIR filter 51 and the second FIR filter 52 are designed so that at the first position P1 and the second position P2, they approach the amplitude frequency characteristics of the target test sound.

[0079] On the other hand, if the difference is less than or equal to a threshold, the information processing device 100 determines that the termination condition is met (Yes in step S14) and transmits filter characteristic information indicating the filter characteristics of the first FIR filter 51 and the second FIR filter 52 determined in step S13 to the speaker device 1 (step S15). The speaker device 1 receives the transmitted filter characteristic information via the communication interface 73, and the processor 71 updates the filter characteristics of the first FIR filter 51 and the second FIR filter 52 stored in the memory 72 to the filter characteristics indicated by the received filter characteristic information. The processor 71 also sets the updated filter characteristics to the first FIR filter 51 and the second FIR filter 52.

[0080] In step S14, the information processing device 100 may also determine that the termination condition is met if a predetermined time (number of times) has elapsed.

[0081] Through adaptive filter design by the information processing device 100, the filter characteristics of the first FIR filter 51 and the second FIR filter 52 are determined such that the difference in sound pressure between the test sound at the first position P1 and the test sound at the second position P2 is reduced by a predetermined amount of sound pressure. The processor 71 operates the signal processing circuit 50 with the determined filter characteristics. As a result, the filter characteristics of the first FIR filter 51 and the second FIR filter 52 are set such that the sound pressure of the sound based on the first audio signal at the second position P2 is reduced by a predetermined value or more compared to the sound pressure of the sound based on the first audio signal at the first position P1.

[0082] Furthermore, the design of the filter characteristics of the third FIR filter 53 and the fourth FIR filter 54 is carried out in the same manner as the design of the filter characteristics of the first FIR filter 51 and the second FIR filter 52 described above. For example, the explanation of the design method for the filter characteristics of the first FIR filter 51 and the second FIR filter 52, as shown using Figures 3 and 4 above, can be explained by substituting the first FIR filter 51, the second FIR filter 52, the first position P1, the second position P2, and the input interface 70a with the third FIR filter 53, the fourth FIR filter 54, the third position P3, the fourth position P4, and the input interface 70b, respectively.

[0083] Adaptive filter design by the information processing device 100 is performed, for example, as an initial setting during the manufacturing of the speaker device 1, but it may also be performed after the speaker device 1 has been installed.

[0084] Furthermore, the processes from steps S11 to S14 described above may also be performed for a plurality of first positions P1 located on the positive X-axis side of the first speaker 10 and a plurality of second positions P2 located on the negative X-axis side of the second speaker 20. In this case, the positions of microphones 111 and 112 are moved relative to the speaker device 1 in accordance with the plurality of first positions P1 and the plurality of second positions P2, and steps S11 and S12 are performed. Then, in step S13, for example, the information processing device 100 determines the filter characteristics of the first FIR filter 51 and the second FIR filter 52 such that the amplitude-frequency characteristics of the test sound results acquired at the plurality of first positions P1 asymptotically approach the target amplitude-frequency characteristics of the plurality of first positions P1 as a whole, and the amplitude-frequency characteristics of the test sound results acquired at the plurality of second positions P2 asymptotically approach the target amplitude-frequency characteristics of the plurality of second positions P2 as a whole. In other words, the filter characteristics of the first FIR filter 51 and the second FIR filter 52 are determined so that the difference between the target amplitude-frequency characteristics and the overall values ​​of the multiple first positions P1 and the multiple second positions P2 is minimized. As a result, the first FIR filter 51 and the second FIR filter 52 have filter characteristics that adjust the frequency-specific phase and amplitude of the input signal so that the sound pressure of the sound based on the first audio signal at each of the multiple second positions P2 decreases by a predetermined value or more when the first sound S1 and the second sound S2 overlap, relative to the sound pressure of the sound based on the first audio signal at each of the multiple first positions P1. The arrangement of the multiple first positions P1 and the multiple second positions P2 is not particularly limited, but for example, they are arranged along an arc centered on the center of the speaker device 1 when viewed from above.

[0085] Similarly, the processes described in steps S11 to S14 may be applied to a plurality of third positions P3 located on the negative X-axis side of the second speaker 20 and a plurality of fourth positions P4 located on the positive X-axis side of the first speaker 10. As a result, the third FIR filter 53 and the fourth FIR filter 54 will have filter characteristics that adjust the frequency-specific phase and amplitude of the input signal so that the sound pressure of the sound based on the second audio signal at each of the plurality of fourth positions P4 decreases by a predetermined value or more with respect to the sound pressure of the sound based on the second audio signal at each of the plurality of third positions P3 as the first sound S1 and the second sound S2 overlap.

[0086] [Effects, etc.] In speaker device 1, the directivity of sound can be enhanced by having the first speaker 10 output the first sound S1 described above, and the second speaker 20 output the second sound S2 described above. The first sound S1 is a sound based on the first output signal OUT1, which is the output of the first FIR filter 51, and the fourth output signal OUT4, which is the output of the fourth FIR filter 54. The second sound S2 is a sound based on the second output signal OUT2, which is the output of the second FIR filter 52, and the third output signal OUT3, which is the output of the third FIR filter 53.

[0087] As described above, the first FIR filter 51 and the second FIR filter 52 have filter characteristics that adjust the frequency-specific phase and amplitude of the first audio signal so that the sound pressure of the sound based on the first audio signal at the second position P2 is reduced by a predetermined value or more relative to the sound pressure of the sound based on the first audio signal at the first position P1. In other words, the second sound S2 output from the second speaker 20 includes a cancellation sound whose phase and amplitude are adjusted for each frequency so that it overlaps with the first sound S1 at the second position P2 and cancels out the sound based on the first audio signal in the first sound S1. Furthermore, the third FIR filter 53 and the fourth FIR filter 54 have filter characteristics that adjust the frequency-specific phase and amplitude of the second audio signal so that the sound pressure of the sound based on the second audio signal at the fourth position P4 is reduced by a predetermined value or more relative to the sound pressure of the sound based on the second audio signal at the third position P3. In other words, the first sound S1 output from the first speaker 10 includes a cancellation sound whose phase and amplitude are adjusted for each frequency so as to cancel out the sound based on the second audio signal in the second sound S2 by overlapping with the second sound S2 at the fourth position P4.

[0088] When canceling sound with a cancellation sound, simply outputting a cancellation sound with the opposite phase, as in the technique described in Patent Document 1, is ineffective over a wide frequency range because the way the sound propagates changes depending on the frequency. In contrast, in speaker device 1, the first sound S1 and second sound S2 contain cancellation sounds whose phase and amplitude are adjusted for each frequency. Therefore, it is possible to cancel sound based on the first audio signal over a wide frequency range at the second position P2. Similarly, it is possible to cancel sound based on the second audio signal over a wide frequency range at the fourth position P4. Thus, the directivity of sound in speaker device 1 can be improved.

[0089] Furthermore, speaker device 1 achieves sound directivity such that at a first position P1 located in the positive X-axis direction from the first speaker 10, sound based on the first audio signal is heard, and at a second position P2 located in the negative X-axis direction from the second speaker 20, sound based on the second audio signal is heard. Therefore, it is possible to create an environment where different sounds can be heard in the area located in the positive X-axis direction from the first speaker 10 and in the area located in the negative X-axis direction from the second speaker 20. In addition, speaker device 1 achieves sound directivity based on the first audio signal and sound directivity based on the second audio signal using two speakers, the first speaker 10 and the second speaker 20. Therefore, there is no need to provide a separate speaker to output a cancellation sound to cancel out the sound based on the first audio signal and the sound based on the second audio signal, which simplifies and miniaturizes the configuration of speaker device 1.

[0090] [Modification 1] Next, Modification 1 of the embodiment will be described. In the following description of Modification 1, the differences from the embodiment will be the main focus, and the similarities will be omitted or simplified.

[0091] Figure 5 is a plan view showing an example of the external appearance of the speaker device 2 according to this modified example. Figure 5 shows the external appearance of the speaker device 2 as viewed from above (in the Z-axis positive direction). For clarity, the sound-absorbing materials 31 and 32 are given a dot pattern in Figure 5 and the plan views of the speaker device described thereafter.

[0092] As shown in Figure 5, the speaker device 2 according to this modified example differs from the speaker device 1 according to the embodiment in that it further includes sound-absorbing materials 31 and 32 and sound-reflecting materials 41 and 42.

[0093] The sound-absorbing material 31 is a plate-shaped member that absorbs the first sound S1 that is attempting to travel from the first speaker 10 in the negative X-axis direction. The sound-absorbing material 31 is located between the first speaker 10 and the second speaker 20. The sound-absorbing material 31 extends along the YZ plane perpendicular to the positive X-axis direction. The sound-absorbing material 31 is attached, for example, to the end of the first housing 10b on the negative X-axis side.

[0094] In speaker device 2, the sound-absorbing material 31 can absorb the first sound S1 that tends to wrap around the first speaker 10 in the negative X-axis direction. Therefore, the sound based on the first audio signal contained in the first sound S1 can be reduced in the area in the negative X-axis direction from the first speaker 10. Thus, the directivity of the sound based on the first audio signal can be further enhanced.

[0095] Furthermore, the inclusion of sound-absorbing material 31 in speaker device 2 is also effective when speaker device 2 transmits sound based on the first audio signal without receiving a second audio signal. In such cases, the area on the negative X-axis side of the first speaker 10 becomes an area where sound from speaker device 2 is not heard, and therefore, even if the sound pressure of the sound based on the first audio signal is low in this area, it will stand out. For this reason, in this case, the absorption of the first sound S1 by sound-absorbing material 31 is particularly effective in controlling the sound environment.

[0096] The sound-absorbing material 32 is a plate-shaped member that absorbs the second sound S2 that is attempting to travel from the second speaker 20 in the positive X-axis direction. The sound-absorbing material 32 is located between the first speaker 10 and the second speaker 20. Furthermore, the sound-absorbing material 32 is positioned on the negative X-axis side relative to the sound-absorbing material 31. The sound-absorbing material 32 extends along the YZ plane perpendicular to the positive X-axis direction. The sound-absorbing material 32 is attached, for example, to the end of the second housing 20b on the positive X-axis side.

[0097] In speaker device 2, the sound-absorbing material 32 can absorb the second sound S2 that tries to wrap around the second speaker 20 in the positive X-axis direction. Therefore, the sound based on the second audio signal contained in the second sound S2 can be reduced in the area on the positive X-axis side of the second speaker 20. Thus, the directivity of the sound based on the second audio signal can be further enhanced.

[0098] When viewed from the positive X-axis direction, the sound-absorbing materials 31 and 32 extend outward beyond the first speaker 10 and the second speaker 20. Also, when viewed from the positive X-axis direction, the centers of the sound-absorbing materials 31 and 32 coincide, for example, with the centers of the first diaphragm 10a and the second diaphragm 20a. Furthermore, when viewed from the positive X-axis direction, the contour of the sound-absorbing material 31 coincides with the contour of the sound-absorbing material 32. The external shape of the sound-absorbing materials 31 and 32 when viewed from the positive X-axis direction is, for example, rectangular, but may also be other shapes such as circular or elliptical.

[0099] The sound-absorbing materials constituting the sound-absorbing materials 31 and 32 are not particularly limited, but the sound-absorbing materials 31 and 32 include, for example, a Helmholtz resonator or a foam having open cells such as a sponge. The sound-absorbing materials 31 and 32 may be composite materials containing multiple types of sound-absorbing materials. For example, in the sound-absorbing materials 31 and 32, a plate-shaped Helmholtz resonator and a plate-shaped foam may be laminated. By including a Helmholtz resonator in the sound-absorbing materials 31 and 32, it is possible to absorb sounds in the mid-to-low frequency range, which are more easily diffused than high-frequency sounds.

[0100] The sound reflecting material 41 is a plate-shaped member that reflects the components of the first sound S1 incident on the sound absorbing material 31 that were not absorbed by the sound absorbing material 31. By reflecting these components, the sound pressure of the sound based on the first audio signal can be further reduced in the area on the negative X-axis side of the first speaker 10, thereby improving the directivity of the sound based on the first audio signal.

[0101] The sound reflecting material 41 is located between the sound absorbing material 31 and the second speaker 20. The sound reflecting material 41 is also sandwiched between the sound absorbing material 31 and the sound absorbing material 32 together with the sound reflecting material 42. The sound reflecting material 41 extends along the YZ plane perpendicular to the positive X-axis direction. When viewed from the positive X-axis direction, the contour of the sound reflecting material 41 coincides with, for example, the contour of the sound absorbing material 31. When viewed from the positive X-axis direction, the entirety of the sound absorbing material 31 overlaps with, for example, the sound reflecting material 41. The sound absorbing material 31 is provided on the surface of the sound reflecting material 41 on the positive X-axis side.

[0102] The sound reflecting material 42 is a plate-shaped member that reflects the components of the second sound S2 incident on the sound absorbing material 32 that were not absorbed by the sound absorbing material 32. By reflecting these components, the sound pressure of the sound based on the second audio signal can be further reduced in the area on the positive X-axis side of the second speaker 20, thereby increasing the directivity of the sound based on the second audio signal. The sound reflecting material 42 is located between the sound absorbing material 32 and the first speaker 10. The sound reflecting material 42 extends along the YZ plane perpendicular to the positive X-axis direction. When viewed from the negative X-axis side, the contour of the sound reflecting material 42 coincides with, for example, the contour of the sound absorbing material 32. When viewed from the negative X-axis side, the entire sound absorbing material 32 overlaps with, for example, the sound reflecting material 42. The sound absorbing material 32 is provided on the negative X-axis side of the sound reflecting material 42.

[0103] The sound reflecting materials 41 and 42 are, for example, metal or resin plates. The sound reflecting material 41 may be integrated with the sound absorbing material 31. The sound reflecting material 42 may also be integrated with the sound absorbing material 32. Furthermore, the sound reflecting material 41 and the sound reflecting material 42 do not have to be formed separately, but may be a single plate sandwiched between the sound absorbing material 31 and the sound absorbing material 32.

[0104] The speaker device 2 does not necessarily need to be equipped with sound reflecting materials 41 and 42.

[0105] [Modified Example 2] Next, modified example 2 of the embodiment will be described. In the following description of modified example 2, the differences from the embodiment and modified example 1 of the embodiment will be explained, and the explanation of the common points will be omitted or simplified.

[0106] Figure 6 is a plan view showing an example of the external appearance of the speaker device 3 according to this modified example. Figure 6 shows the external appearance of the speaker device 3 as viewed from above (in the Z-axis positive direction).

[0107] As shown in Figure 6, the speaker device 3 according to this modified example differs from the speaker device 2 according to the first modified example of the embodiment in that it further includes a first horn 11 and a second horn 21. By including the first horn 11 and the second horn 21, the speaker device 3 can control the range in which sound based on the first audio signal is heard by the first sound S1 and the range in which sound based on the second audio signal is heard by the second sound S2. Although the speaker device 3 includes sound-absorbing materials 31 and 32 and sound-reflecting materials 41 and 42, it may also be configured without sound-absorbing materials 31 and 32 and sound-reflecting materials 41 and 42, as in the speaker device 1. Furthermore, the speaker device 3 may include only one of the first horn 11 and the second horn 21.

[0108] The first horn 11 emits the first sound S1 output from the first speaker 10 in the positive X-axis direction. Emitting sound in the positive X-axis direction means that the sound is emitted with the positive X-axis direction as the center. The first horn 11 is positioned on the positive X-axis side relative to the first speaker 10. When viewed from the positive X-axis side, the center of the first diaphragm 10a and the center of the first horn 11 coincide. The first horn 11 is cylindrical and has openings in the positive X-axis direction and the negative X-axis direction. The first horn 11 is attached to the end of the first housing 10b on the positive X-axis side so as to surround the space on the positive X-axis side of the first speaker 10. The first horn 11 gradually widens as it extends in the positive X-axis direction. The opening of the first horn 11 on the negative X-axis side is blocked by the first speaker 10. The opening of the first horn 11 on the positive X-axis side is open. The axial direction of the first horn 11 coincides with the positive X-axis direction.

[0109] The first sound S1 output from the first speaker 10 has its directivity in the positive X-axis direction enhanced by the first horn 11. This makes it possible to narrow the range of sound directivity based on the first audio signal.

[0110] The second horn 21 emits the second sound S2 output from the second speaker 20 in the negative X-axis direction. Emitting sound in the negative X-axis direction means that the sound is emitted with the negative X-axis direction as the center. The second horn 21 is positioned on the negative X-axis side relative to the second speaker 20. When viewed from the negative X-axis side, the center of the second diaphragm 20a and the center of the second horn 21 coincide. The second horn 21 is cylindrical and has openings in the positive X-axis direction and the negative X-axis direction. The second horn 21 is attached to the negative X-axis side end of the second housing 20b so as to surround the space on the negative X-axis side of the second speaker 20. The second horn 21 gradually widens as it extends in the negative X-axis direction. The opening of the second horn 21 on the positive X-axis side is blocked by the second speaker 20. The opening of the second horn 21 on the negative X-axis side is open. The axial direction of the second horn 21 coincides with the negative X-axis direction.

[0111] The second sound S2 output from the second speaker 20 has its directivity in the negative X-axis direction enhanced by the second horn 21. This narrows the range of sound directivity based on the second audio signal.

[0112] [Modification 3] Next, Modification 3 of the embodiment will be described. In the following description of Modification 3, the differences from the embodiment and Modifications 1 and 2 of the embodiment will be described, and the explanation of the common points will be omitted or simplified.

[0113] Figure 7 is a plan view showing an example of the external appearance of the speaker device 4 according to this modified example. Figure 7 shows the external appearance of the speaker device 4 when viewed from above (in the Z-axis positive direction).

[0114] As shown in Figure 7, the speaker device 4 according to this modified example differs from the speaker device 2 according to the first modified example of the embodiment in that it further includes a first diffuser 12 and a second diffuser 22. By including the first diffuser 12 and the second diffuser 22, the speaker device 4 can control the range in which sound based on the first audio signal is heard by the first sound S1 and the range in which sound based on the second audio signal is heard by the second sound S2. Although the speaker device 4 includes sound-absorbing materials 31 and 32 and sound-reflecting materials 41 and 42, it may also be configured without sound-absorbing materials 31 and 32 and sound-reflecting materials 41 and 42, as in the speaker device 1. Furthermore, the speaker device 4 may include only one of the first diffuser 12 and the second diffuser 22.

[0115] The first diffuser 12 is a component that diffuses the first sound S1 output from the first speaker 10. Because the first sound S1 is diffused by the first diffuser 12, the range over which the sound based on the first audio signal in the first sound S1 can be heard can be widened. In addition, if the second sound S2 wraps around to the positive X-axis side from the first speaker 10, the first sound S1 can cancel out the sound based on the second audio signal in the second sound S2 over a wide range.

[0116] The first diffuser 12 is positioned opposite the first speaker 10 on the output side of the first sound S1, that is, on the positive X-axis side relative to the first speaker 10. The first diffuser 12 is also connected to the positive X-axis end of the first housing 10b via a connecting rod. In the example shown in Figure 7, the first diffuser 12 has a conical portion that protrudes toward the first speaker 10. The shape of the first diffuser 12 is not particularly limited as long as it can diffuse the first sound S1.

[0117] The second diffuser 22 is a component that diffuses the second sound S2 output from the second speaker 20. Because the second sound S2 is diffused by the second diffuser 22, the range in which the sound based on the second audio signal in the second sound S2 can be heard can be widened. In addition, if the first sound S1 wraps around to the negative X-axis side from the second speaker 20, the second sound S2 can cancel out the sound based on the first audio signal in the first sound S1 over a wide range.

[0118] The second diffuser 22 is positioned opposite the second speaker 20 on the output side of the second sound S2, that is, on the negative X-axis side relative to the second speaker 20. The second diffuser 22 is also connected to the end of the second housing 20b on the negative X-axis side via a connecting rod. In the example shown in Figure 7, the second diffuser 22 has a conical portion that protrudes toward the second speaker 20. The shape of the second diffuser 22 is not particularly limited as long as it can diffuse the second sound S2.

[0119] The speaker device 4 may further include at least one of the first horn 11 and the second horn 21 described above. In this case, the speaker device 4 may also include only one of the first diffuser 12 and the second diffuser 22 as described above. There are no particular restrictions on which of the first horn 11, second horn 21, first diffuser 12 and second diffuser 22 the speaker device 4 includes. For example, the speaker device 4 may include all of the first horn 11, second horn 21, first diffuser 12 and second diffuser 22. Alternatively, for example, the speaker device 4 may include only the first horn 11 and the second diffuser 22 from the first horn 11, second horn 21, first diffuser 12 and second diffuser 22. Furthermore, for example, the speaker device 4 may include only the first horn 11 and the first diffuser 12 from the first horn 11, second horn 21, first diffuser 12, and second diffuser 22. When the speaker device 4 includes the first horn 11 and the first diffuser 12, the first horn 11 may emit the first sound S1 diffused by the first diffuser 12, and the first diffuser 12 may diffuse the first sound S1 emitted by the first horn 11. The same applies to the second sound S2 when the speaker device 4 includes the second horn 21 and the second diffuser 22.

[0120] [Modification 4] Next, Modification 4 of the embodiment will be described. In the following description of Modification 4, the differences from the embodiment and Modifications 1 to 3 will be explained in detail, and the explanation of the common points will be omitted or simplified.

[0121] Figure 8 is a block diagram showing an example of the functional configuration of the speaker device 5 according to this modified example.

[0122] As shown in Figure 8, the speaker device 5 according to this modified example differs from the speaker device 1 according to the embodiment in that it is equipped with a signal processing circuit 50A instead of a signal processing circuit 50. Note that the speaker device according to any of the above modified examples 1 to 3 may also be equipped with a signal processing circuit 50A.

[0123] The signal processing circuit 50A differs from the signal processing circuit 50 in that it includes low-pass filters 63a and 63b and high-pass filters 64a and 64b instead of filters 61a and 61b, and further includes adders 65a and 65b.

[0124] In the signal processing circuit 50A, the first FIR filter 51 and the second FIR filter 52 perform signal processing on the output of the low-pass filter 63a, which is a signal in a frequency band of a part of the first audio signal. In addition, in the signal processing circuit 50A, the third FIR filter 53 and the fourth FIR filter 54 perform signal processing on the output of the low-pass filter 63b, which is a signal in a frequency band of a part of the second audio signal.

[0125] The first audio signal is input to the low-pass filter 63a via the input interface 70a. The low-pass filter 63a is set to a predetermined cutoff frequency and allows signals in the frequency band lower than the cutoff frequency of the first audio signal to pass through. Inputting the first audio signal to the low-pass filter 63a reduces the processing required in subsequent stages. Also, because high-frequency sounds have high directivity, the high-frequency sounds of the first tone S1 output from the first speaker 10 in the positive X-axis direction are unlikely to reach the second position P2, which is located on the negative X-axis side of the second speaker 20. Therefore, even if the high-frequency range is blocked by the low-pass filter 63a, the impact on the directivity of the sound based on the first audio signal is small.

[0126] The second audio signal is input to the low-pass filter 63b via the input interface 70b. The low-pass filter 63b is set to a predetermined cutoff frequency and allows signals in the second audio signal with a frequency band lower than the cutoff frequency to pass through. Inputting the second audio signal to the low-pass filter 63b reduces the processing required in subsequent stages. Also, because high-frequency sounds have high directivity, the high-frequency sounds of the second sound S2 output from the second speaker 20 in the negative X-axis direction are unlikely to reach the fourth position P4, which is located on the positive X-axis side of the first speaker 10. Therefore, even if the high-frequency range is blocked by the low-pass filter 63b, the impact on the directivity of the sound based on the second audio signal is small.

[0127] The cutoff frequencies of the low-pass filters 63a and 63b are, for example, between 1 kHz and 5 kHz. The cutoff frequencies of the low-pass filters 63a and 63b may also be between 2 kHz and 4 kHz.

[0128] The first audio signal is input to the high-pass filter 64a via the input interface 70a. The high-pass filter 64a is set to a predetermined cutoff frequency and allows signals of the first audio signal with a frequency higher than the cutoff frequency to pass through.

[0129] The high-pass filter 64b receives the second audio signal via the input interface 70b. The high-pass filter 64b is set to a predetermined cutoff frequency and allows signals of the second audio signal with a frequency higher than the cutoff frequency to pass through.

[0130] The cutoff frequencies of the high-pass filters 64a and 64b are set to be the same as, for example, the cutoff frequencies of the low-pass filters 63a and 63b.

[0131] The adder 65a adds the output of the first FIR filter 51 and the output of the high-pass filter 64a and outputs the added signal. In the signal processing circuit 50A, the output of the first FIR filter 51 and the output of the high-pass filter 64a are added by the adder 65a to generate the first output signal OUT1. In other words, in this modified example, the first output signal OUT1 is the output of the adder 65a.

[0132] The adder 65b adds the output of the third FIR filter 53 and the output of the high-pass filter 64b and outputs the added signal. In the signal processing circuit 50A, the output of the third FIR filter 53 and the output of the high-pass filter 64b are added by the adder 65b to generate the third output signal OUT3. In other words, in this modified example, the third output signal OUT3 is the output of the adder 65b.

[0133] In the signal processing circuit 50A, adder 62a adds the first output signal OUT1, which is the output of adder 65a, and the fourth output signal OUT4, which is the output of the fourth FIR filter 54, and outputs the added signal to the first speaker 10. Also in the signal processing circuit 50A, adder 62b adds the third output signal OUT3, which is the output of adder 65b, and the second output signal OUT2, which is the output of the second FIR filter 52, and outputs the added signal to the second speaker 20. Note that the order of addition by the signal processing circuit 50A shown in Figure 8 may differ from the order of addition by the signal processing circuit 50A shown in Figure 8, as long as the output of the high-pass filter 64a, the output of the first FIR filter 51, and the output of the fourth FIR filter 54 are added and input to the first speaker 10. For example, the signal processing circuit 50A may add the output of the high-pass filter 64a after adding the output of the first FIR filter 51 and the output of the fourth FIR filter 54. Similarly, the order of addition by the signal processing circuit 50A shown in Figure 8 may differ from the order of addition by the signal processing circuit 50A shown in Figure 8, as long as the output of the high-pass filter 64b, the output of the third FIR filter 53, and the output of the second FIR filter 52 are added and input to the second speaker 20. For example, the signal processing circuit 50A may add the output of the high-pass filter 64b after adding the output of the third FIR filter 53 and the output of the second FIR filter 52.

[0134] In the signal processing circuit 50A, the processor 71 stores the filter characteristics of the low-pass filters 63a and 63b and the high-pass filters 64a and 64b, received from an external information processing device 100, etc., via the communication interface 73, in the memory 72. The processor 71 may also update the filter characteristics of the low-pass filters 63a and 63b and the high-pass filters 64a and 64b stored in the memory 72 based on information received from the external information processing device 100, etc. For example, when the power to the speaker device 5 is turned on, the processor 71 reads the filter characteristics of the low-pass filters 63a and 63b and the high-pass filters 64a and 64b from the memory 72 and sets them for each filter.

[0135] (Other Embodiments) As described above, embodiments (including modifications) have been explained as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited thereto and can be applied to embodiments that are modified, replaced, added, omitted, etc. as appropriate. Furthermore, it is possible to create new embodiments by combining the components described in the above embodiments.

[0136] For example, in the above embodiment, the filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54 were determined by adaptive filter design, but are not limited to this. The filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54 may be determined by methods other than adaptive filter design. For example, the filter characteristics of the first FIR filter 51, the second FIR filter 52, the third FIR filter 53, and the fourth FIR filter 54 may be designed using simulation or the like.

[0137] Furthermore, for example, in the above embodiment, the signal processing circuits 50 and 50A are input to the first audio signal and the second audio signal, but this is not limited to this. The signal processing circuits 50 and 50A may receive only the first audio signal out of the two audio signals. In this case, the signal processing circuits 50 and 50A do not need to have a configuration for performing signal processing on the second audio signal. Also in this case, the input interface 70b is not required.

[0138] Furthermore, in the above embodiment, a process executed by a specific processing circuit, such as a processor, may be executed by another processing circuit. Also, the order of multiple processes may be changed, and multiple processes may be executed in parallel. In addition, the processor executing the above program may be one or multiple. That is, centralized processing may be performed, or distributed processing may be performed.

[0139] Furthermore, the general or specific aspects of this disclosure may be implemented as a system, apparatus, method, integrated circuit, computer program, or recording medium such as a computer-readable CD-ROM. They may also be implemented in any combination of systems, apparatus, methods, integrated circuits, computer programs, and recording media. For example, this disclosure may be implemented as a speaker system including a speaker device and an information processing device. The speaker system may be implemented by multiple devices or by a single device. If the speaker system is implemented by multiple devices, the components of the speaker system may be distributed among the multiple devices in any way.

[0140] Furthermore, this disclosure also includes forms obtained by applying various modifications to the embodiments that a person skilled in the art could conceive, and forms realized by arbitrarily combining the components and functions of the embodiments without departing from the spirit of this disclosure.

[0141] This disclosure can be used in directional speaker devices and the like.

[0142] 1, 2, 3, 4, 5 Speaker device 10 First speaker 10a First diaphragm 10b First enclosure 11 First horn 12 First diffuser 20 Second speaker 20a Second diaphragm 20b Second enclosure 21 Second horn 22 Second diffuser 31, 32 Sound absorbing material 41, 42 Sound reflecting material 50, 50A Signal processing circuit 51 First FIR filter 52 Second FIR filter 53 Third FIR filter 54 Fourth FIR filter 61a, 61b Filters 62a, 62b, 65a, 65b Adder 63a, 63b Low-pass filter 64a, 64b High-pass filter 70a, 70b Input interface 71 Processor 72 Memory 73 Communication interface 100 Information processing device 111, 112 Microphone OUT1 First output signal OUT2 Second output signal OUT3 Third output signal OUT4 Fourth output signal P1 First position P2 Second position P3 Third position P4 Fourth position S1 First tone S2 Second tone

Claims

1. A signal processing circuit that performs signal processing on an input first audio signal to generate a first output signal and a second output signal; a first speaker that outputs a first sound based on the first output signal in a first direction; a second speaker positioned on the side of the first speaker in a second direction opposite to the first direction, and that outputs a second sound based on the second output signal in the second direction; and a sound-absorbing material positioned between the first speaker and the second speaker, extending along a plane perpendicular to the first direction, wherein the signal processing circuit has a first filter and a second filter that perform signal processing on signals in at least a portion of the frequency band of the first audio signal, the first output signal is generated based on the output of the first filter, and the second output signal is generated based on the output of the second filter. The first filter and the second filter have filter characteristics that adjust the frequency-dependent phase and amplitude of signals in at least a portion of the frequency band of the first audio signal so that the sound pressure of the sound based on the first audio signal at the second position decreases by a predetermined value or more with respect to the sound pressure of the sound based on the first audio signal at the first position due to the overlap of the first sound and the second sound, and the first position is located on the first direction side of the first speaker, and the second position is located on the second direction side of the first position.

2. The speaker device according to claim 1, further comprising at least one of a first horn that emits the first sound output from the first speaker in a first direction, and a second horn that emits the second sound output from the second speaker in a second direction.

3. The speaker device according to claim 1, further comprising at least one of a first diffuser for diffusing the first sound output from the first speaker, and a second diffuser for diffusing the second sound output from the second speaker.

4. The speaker device according to claim 1, further comprising: at least one of a first horn that emits the first sound output from the first speaker in a first direction, and a second horn that emits the second sound output from the second speaker in a second direction; and at least one of a first diffuser that diffuses the first sound output from the first speaker, and a second diffuser that diffuses the second sound output from the second speaker.

5. The speaker device according to claim 1, further comprising a sound-reflecting material disposed between the sound-absorbing material and the second speaker, and extending along a plane perpendicular to the first direction.

6. The signal processing circuit performs signal processing on the input second audio signal to generate a third output signal and a fourth output signal; the first speaker outputs the first sound based on the first output signal and the fourth output signal; the second speaker outputs the second sound based on the second output signal and the third output signal; the signal processing circuit has a third filter and a fourth filter that perform signal processing on signals in at least a portion of the frequency band of the second audio signal; the third output signal is generated based on the output of the third filter; the fourth output signal is generated based on the output of the fourth filter; the third filter and the fourth filter have filter characteristics that adjust the frequency-specific phase and amplitude of signals in at least a portion of the frequency band of the second audio signal so that the sound pressure of the sound based on the second audio signal at the fourth position decreases by a predetermined value or more with respect to the sound pressure of the sound based on the second audio signal at the third position due to the overlap of the first and second sounds; the third position is located on the second side of the second speaker. The speaker device according to any one of claims 1 to 5, wherein the fourth position is located on the first direction side than the third position.

7. A signal processing circuit that performs signal processing on an input first audio signal to generate a first output signal and a second output signal, and performs signal processing on an input second audio signal to generate a third output signal and a fourth output signal; a first speaker that outputs a first sound based on the first output signal and the fourth output signal in a first direction; and a second speaker that is positioned on the second direction side opposite to the first direction relative to the first speaker and outputs a second sound based on the second output signal and the third output signal in the second direction, wherein the signal processing circuit has a first filter and a second filter that perform signal processing on signals in at least a portion of the frequency band of the first audio signal, and a third filter and a fourth filter that perform signal processing on signals in at least a portion of the frequency band of the second audio signal, wherein the first output signal is generated based on the output of the first filter, the second output signal is generated based on the output of the second filter, the third output signal is generated based on the output of the third filter, and the fourth output signal is generated based on the output of the fourth filter, The first and second filters have filter characteristics that adjust the frequency-dependent phase and amplitude of the signals in at least a portion of the frequency band of the first audio signal so that the sound pressure of the sound based on the first audio signal at the second position decreases by a predetermined value or more with respect to the sound pressure of the sound based on the first audio signal at the first position due to the overlap of the first and second sounds; the third and fourth filters have filter characteristics that adjust the frequency-dependent phase and amplitude of the signals in at least a portion of the frequency band of the second audio signal so that the sound pressure of the sound based on the second audio signal at the fourth position decreases by a predetermined value or more with respect to the sound pressure of the sound based on the second audio signal at the third position due to the overlap of the first and second sounds; the first position is located on the first direction side of the first speaker; the second position is located on the second direction side of the first position; the third position is located on the second direction side of the second speaker; and the fourth position is located on the first direction side of the third position.

8. The speaker device according to claim 7, further comprising at least one of a first horn that emits the first sound output from the first speaker in a first direction, and a second horn that emits the second sound output from the second speaker in a second direction.

9. The speaker device according to claim 7, further comprising at least one of a first diffuser for diffusing the first sound output from the first speaker, and a second diffuser for diffusing the second sound output from the second speaker.

10. The speaker device according to claim 7, further comprising: at least one of a first horn that emits the first sound output from the first speaker in a first direction, and a second horn that emits the second sound output from the second speaker in a second direction; and at least one of a first diffuser that diffuses the first sound output from the first speaker, and a second diffuser that diffuses the second sound output from the second speaker.

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