WO2023276835A1

WO2023276835A1 - Speaker system

Info

Publication number: WO2023276835A1
Application number: PCT/JP2022/024978
Authority: WO
Inventors: 勉貝塚
Original assignee: 学校法人工学院大学
Priority date: 2021-06-28
Filing date: 2022-06-22
Publication date: 2023-01-05
Also published as: JPWO2023276835A1

Abstract

A speaker system (10) comprises: a first speaker array (12) configured by arranging a plurality of first speakers (16) on a straight line; and a second speaker array (14) configured by arranging a plurality of second speakers (18) on a straight line. A first phase setting unit (20) sets, for the plurality of first speakers (16), a phase of a drive signal on the basis of a tangent method so as to output a sound beam in the shape of a circular arc C1. A second phase setting unit (22) sets, for the plurality of second speakers (18), the phase of the drive signal on the basis of the tangent method so as to output a sound beam in the shape of a circular arc C2. Thus, a listening point is set at the point of intersection LP1 between the two circular arcs C1 and C2.

Description

speaker system

The present disclosure relates to a speaker system.

　Technologies related to the generation of a so-called local sound field are being researched so that the sound output from the speaker can be heard only within a specific area. Japanese Patent Application Laid-Open No. 2016-136656 discloses a speaker system including a speaker array configured by distributing a plurality of sub-speakers on an array surface and a mechanism for independently controlling the volume and amplitude phase of each sub-speaker. disclosed. In this speaker system, attention is focused on the cancellation phenomenon of sound that appears on a rectangular flat plate, and a technique is described for generating a local sound field by simulating the vibration mode of the rectangular flat plate with a speaker array. Also known is a technique for generating an arc-shaped sound beam using the principle of the tangent method (also called the stationary phase method) (Zhao, et al., J. Acoust. Soc. Am. 137(2) , 1036-1039, 2015, Zhao, et al., ICSV22, Florence, Italy, 12-16 July 2015)

All of the above technologies relate to the generation of a local sound field, but there is room for improvement in making it possible to set the listening point at any position.

The present disclosure obtains a speaker system capable of setting a listening point at an arbitrary position in a speaker system capable of generating a local sound field.

A speaker system according to a first aspect includes a first speaker array configured by arranging a plurality of first speakers along a straight line, and a second speaker array configured by arranging a plurality of second speakers along the straight line. and a first phase setting unit that sets the phase of the drive signal based on the tangent method so that the sound beams are output in an arc shape to the plurality of first speakers constituting the first speaker array. and driving the plurality of second speakers constituting the second speaker array based on the tangential method so that sound beams are output in an arc shape that intersects with the beams output from the first speaker array. and a second phase setting unit that sets the phase of the signal.

In the speaker system according to the first aspect, the first speaker array includes a plurality of first speakers arranged in a straight line. Also, the second speaker array includes a plurality of second speakers arranged in a straight line.

The first phase setting unit sets the phase of the drive signal based on the tangent method so that the sound beams are output in an arc shape to the plurality of first speakers. The second phase setting unit sets the phase of the drive signal based on the tangent method so that the sound beams are output in an arc shape to the plurality of second speakers. Here, the second phase setting unit sets the phase of the driving signal so that a sound beam that intersects with the beam output from the first speaker array is output. By adjusting the amplitude and phase of the beam of sound output from the first speaker array and the beam of sound output from the second speaker array, the sound pressure at the intersection of the beams is increased to approximately double. be able to. As a result, it is possible to generate a local sound field with the intersection of the sound beams as the listening point. Also, if the size or position of the sound beam is changed, the intersection will change, so the listening point can be set at any position. The term "arc shape" as used herein is not limited to a perfect circular arc, but is a concept that includes a wide range of convex curve shapes.

In the speaker system according to the second aspect, in the first aspect, the beam output from the first speaker array and the beam output from the second speaker array have a symmetrical shape.

In the speaker system according to the second aspect, since the first speaker array and the second speaker array output symmetrical sound beams, it is easy to set the listening point that is the intersection point. The term "symmetrical shape" as used herein is a concept that includes a wide range of horizontally inverted shapes and vertically inverted shapes.

A speaker system according to a third aspect is the first aspect or the second aspect, wherein the number of the first speakers forming the first speaker array is the same as the number of the second speakers forming the second speaker array. is a number.

In the speaker system according to the third aspect, by setting the number of the first speaker arrays and the number of the second speaker arrays to be the same, the circular arcs of the sound beams have the same shape. This facilitates the setting of listening points.

In the speaker system according to the fourth aspect, in any one of the first to third aspects, the interval between the adjacent first speakers and the interval between the adjacent second speakers are set to be the same.

In the speaker system according to the fourth aspect, by setting the number of the first speaker arrays and the number of the second speaker arrays to be the same, the circular arcs of the sound beams have the same shape. This facilitates the setting of listening points.

A speaker system according to a fifth aspect is, in any one aspect of the first to first aspects, wherein the first speaker and the second speaker are arranged at an interval of half or less of the upper limit wavelength in the frequency band of the sound to be output. are placed.

In the speaker system according to the fifth aspect, spatial aliasing (spatial error and spectral error) can be suppressed.

A speaker system according to a sixth aspect, in any one of the first to fifth aspects, comprises a moving mechanism for moving the position of at least one of the first speaker array and the second speaker array.

In the speaker system according to the sixth aspect, the listening point can be changed at any time by moving the first speaker array and the second speaker array with the moving mechanism.

A speaker system according to a seventh aspect is any one of the first to sixth aspects, wherein the shape of the beam output from at least one of the first speaker array and the second speaker array is variable. there is

In the speaker system according to the seventh aspect, by changing the shape of the beam, it is possible to change the position of the listening point without moving the speaker array itself. As a method of changing the shape of the beam, there is a method of stopping the output of some of the speakers that make up the speaker array, and a method of changing the phase of each speaker so as to correspond to the tangent line of the arc-shaped beam after the change. and various other methods can be employed.

As described above, according to the speaker system according to the present disclosure, it is possible to set a listening point at an arbitrary position in a speaker system capable of generating a local sound field.

1 is a model diagram schematically showing a beam of sound generated by a speaker system according to an embodiment; FIG. 2 is a graph showing the sound pressure distribution generated by the sound beam shown in FIG. 1, showing the sound pressure distribution in a two-dimensional plane; 2 is a graph showing the sound pressure distribution generated by the sound beam shown in FIG. 1, showing the sound pressure distribution in three-dimensional space; 3 is a graph showing the sound pressure distribution corresponding to FIG. 2 when a rigid sphere with a diameter of 0.1 m is placed at the listening point. 3 is a graph showing the sound pressure distribution corresponding to FIG. 2 when a rigid sphere with a diameter of 0.2 m is placed at the listening point. 3 is a graph showing the sound pressure distribution corresponding to FIG. 2 when a rigid sphere with a diameter of 0.4 m is placed at the listening point. 4 is a graph showing the sound pressure distribution corresponding to FIG. 3 when a rigid sphere with a diameter of 0.4 m is placed at the listening point. 3 is a schematic diagram schematically showing a first speaker array and a second speaker array in the embodiment; FIG. FIG. 11 is a model diagram schematically showing sound beams generated by a speaker system according to a modification; 1 is a model diagram schematically showing a sound beam generated by the tangent method; FIG. FIG. 5 is a model diagram schematically showing a sound beam generated by a method according to a comparative example; 12 is a graph showing the sound pressure distribution generated by the sound beam shown in FIG. 11, showing the distribution in a two-dimensional plane;

A speaker system according to an embodiment will be described with reference to the drawings. The speaker system of this embodiment uses the principle of generating sound beams by the tangent method. The principle of the tangent method will be described below with reference to FIG.

(tangent method)
As shown in FIG. 10, the curved trajectory of the sound beam generated by the tangent method is regarded as a semicircle C centered at coordinates (0, a). Consider a tangent line L to a point on a semicircle C. Assuming that the angle between the tangent line L and the y-axis is θ, and the intersection of the tangent line L and the x-axis is x, the relational expression (1) is obtained.

(1)

Also, when the phase of the point sound source at the coordinates (x, 0) is φ(x), the relationship between the distance along the x-axis and the phase shift is expressed by Equation (2).

... (2)

Formula (3) is derived from formula (2) above.

... (3)

In the above equation (3), dφ is the phase shift between adjacent point sources, dx is the distance between adjacent point sources, and k is the wavenumber. Here, by substituting equation (1) into equation (3) and integrating, equation (4) is obtained.

... (4)

Equation (4) above shows the spatial phase profile of an array of point sources for generating a local sound field along the semicircle C, ie the phase φ of the source at location x. Therefore, when the number of point sound sources of the speaker array is N, it is represented by Equation (5).

(5)

Here, _xn =nd indicates the position of the n-th point sound source, and n=0, 1, 2, . . . d indicates the distance between adjacent point sound sources. A method of setting the spatial phase profile of the speaker array by such a method is called a tangent method.

In the tangent method, only point sound sources on the tangent line extending from a single point on the circle affect the sound pressure at the contact. That is, in FIG. 10, when considering a tangent line L tangent to a single point on the semicircle C, only the point sound source arranged at the point where the tangent line L and the x-axis intersect contributes to the sound pressure at the single point. On the other hand, point sound sources arranged at positions distant from the point where the tangent line L and the x-axis intersect cancel each other. As a result, in the tangent method, the sound pressure is maintained only on the semicircle C in FIG. 10, and an arc-shaped sound beam is generated.

(Structure of speaker system 10)
Next, the speaker system 10 according to this embodiment to which the tangent method is applied will be described. As shown in FIG. 8, speaker system 10 includes first speaker array 12 and second speaker array 14 .

The first speaker array 12 is a linear array, and is configured by arranging a plurality of first speakers 16 at equal intervals on a straight line. The size of the first speaker array 12 and the number and spacing of the first speakers 16 are changed according to the position of the listening point and the frequency band of sound to be output, which will be described later.

In this embodiment, as an example, the audio frequency band is set to 300 Hz to 3400 Hz. The interval between the first speakers 16 serving as point sound sources is set to 0.05 m, and the number of the first speakers 16 is 21. As shown in FIG. That is, the interval between adjacent first speakers 16 is set to a value less than half the wavelength of the sound wave of 3400 Hz.

The second speaker array 14 is a linear array, and is configured by arranging a plurality of second speakers 18 at equal intervals on a straight line. The size of the second speaker array 14 and the number and spacing of the second speakers 18 are changed according to the position of the listening point and the frequency band of the sound to be output, which will be described later. In this embodiment, as an example, the second speaker array 14 has the same configuration as the first speaker array 12 . That is, the interval between the adjacent second speakers 18 is set to 0.05 m, and the number of the second speakers 18 is 21 pieces.

The first speaker array 12 is electrically connected to the first phase setting section 20 , and the second speaker array 14 is electrically connected to the second phase setting section 22 . The first phase setting section 20 sets the phase of the driving signal for each of the plurality of first speakers 16 . Also, the second phase setting unit 22 sets the phase of the drive signal for each of the plurality of second speakers 18 . Although illustration is omitted, a plurality of wirings extend from the first phase setting section 20 and each wiring is connected to the first speaker 16 . Similarly, a plurality of wirings extend from the second phase setting section 22 and each wiring is connected to the second speaker 18 .

The arrangement of the first speaker array 12 and the second speaker array 14 will be described with reference to FIG. With respect to the xy coordinate system shown in FIG. 1, the first speaker array 12 is arranged in a range AR1 from coordinates (0, 0) to coordinates (a, 0) on the x axis. In this embodiment, as an example, the length of the first speaker array 12 is set to 1.0 m, so the length from coordinates (0, 0) to coordinates (a, 0) is 1.0 m. there is

The spatial phase profile of the first speaker array 12 set by the first phase setting unit 20 based on the tangent method generates a quadrant arc C1 centered at coordinates (a, 0). In other words, the first phase setting unit 20 controls the plurality of first speakers 16 constituting the first speaker array 12 based on the tangential method so that sound beams are output in quadrant arcs. to set the phase of the drive signal.

On the other hand, the second speaker array 14 is arranged in a range AR2 from coordinates (b, 0) to coordinates (a+b, 0) on the x-axis. Here, since the coordinates (b, 0) are closer to the origin (0, 0) than the coordinates (a, 0), the second speaker array 14 is partially overlapped with the arrangement area of the first speakers 16. set on a straight line.

Also, the spatial phase profile of the second speaker array 14 set by the second phase setting unit 22 based on the tangent method generates a quadrant arc C2 centered at the coordinates (a+b, a). Here, the arc C2 has a symmetrical shape with respect to the arc C1, and more specifically, has a horizontally inverted shape. For this reason, the second phase setting unit 22 outputs sound beams to the plurality of second speakers 18 constituting the second speaker array 14 in the shape of a quadrant arc that is horizontally inverted from the arc C1. Set the phase of the drive signal based on the tangent method so that

When the arc C1 and the arc C2 are generated as described above, the sound pressure increases at the intersection point LP1 of the arc C1 and the arc C2. That is, the intersection point LP becomes the listening point. The x-coordinate of the intersection point LP1 is represented by Equation (6).

... (6)

Also, the y-coordinate of the intersection point LP1 is obtained by the formula (7) by substituting the formula (6) into the formula y=a−(a ² −x ² ) ⁻¹ of the arc C1.

(7)

Here, the y-coordinate of the intersection point LP1 is equal to the distance from the array surfaces of the first speaker array 12 and the second speaker array 14 to the listening point. Therefore, by changing the coordinates a and b in FIG. 1, the distance of the listening point can be adjusted. That is, by changing the arrangement range of the first speaker array 12 and the arrangement range of the second speaker array 14, the shape (size) of the arc of the sound beam changes, so that the listening point changes.

In addition, although the xy coordinate system has been described in FIG. 1, the local sound field generated by the speaker system 10 is axially symmetrical with respect to the x axis. Therefore, it is possible to confine the local sound field in a three-dimensional space.

(action)
Next, the operation of this embodiment will be described.

In the speaker system 10 of the present embodiment, the second phase setting unit 22 outputs sound beams in an arc shape (symmetrical shape) that is horizontally inverted from the beams output from the first speaker array 12. Set the phase of the drive signal to Thereby, the sound beam output from the first speaker array 12 and the sound beam output from the second speaker array 14 are symmetrical in plan view, and the sound pressure can be strengthened at the intersection LP1. As a result, it is possible to generate a local sound field with the sound beam intersection point LP1 as the listening point.

Also, if the arrangement range of the first speaker array 12 and the second speaker array 14 is changed, the position of the sound beam is changed and the intersection point LP1 is changed, so the listening point can be set at an arbitrary position. That is, a listening point can be set at an arbitrary position in a speaker system capable of generating a local sound field.

Furthermore, in the present embodiment, the configurations of the first speaker array 12 and the second speaker array 14 are the same, so that the arcs C1 and C2 of the sound beams have the same shape. This facilitates setting of the intersection point LP1.

Furthermore, in this embodiment, spatial aliasing can be suppressed by setting the interval between adjacent first speakers 16 and the interval between adjacent second speakers 18 to half or less of the wavelength.

The above action will be explained with reference to the sound pressure distribution.

(sound pressure distribution)
The sound pressure distributions shown in FIGS. 2 and 3 are the sound pressure distributions when the first speaker array 12 and the second speaker array 14 are arranged at the positions shown in FIG. 1 and sound is produced at 2000 Hz. That is, the radius of the curved trajectory of the sound beam is 1.0 m, and the y-coordinate of the listening point LP1 is 0.5 m. In other words, the listening point is set at a position 0.5 m away from the array surface. The sound pressure distribution is based on simulation results using the finite element method and the boundary element method, and darker areas like the roughly triangular area in the lower part of Fig. 2 indicate high sound pressure. . Also, the color is lighter outside the region, indicating that the sound pressure is lower. The streak-like portions extending in the y-direction on the left and right sides of the approximately triangular region are shown in dark colors to distinguish them from other regions. This is a low pressure area.

As shown in FIG. 2, at the intersection point (listening point) LP1, the beams of the first speaker array 12 and the second speaker array 14 overlap with the same amplitude and phase, so it can be confirmed that the sound pressure is improved. Also, the reason why the sound pressure in the area from the listening point to the array surface is high is due to side lobes.

That is, in the area from the listening point to the array surface, the side lobes of the first speaker array 12 and the side lobes of the second speaker array 14 overlap, so the sound pressure is high. On the other hand, in other regions, since the side lobes do not overlap each other, the sound pressure is low. As a result, the local sound field is confined in the region from the listening point to the array plane. Note that when only the first speaker array 12 is output, side lobes appear outside the arc C1. Similarly, when only the second speaker array 14 is output, side lobes appear outside the arc C2.

Also, looking at the sound pressure distribution shown in FIG. 3, it can be confirmed that the local sound field is confined in the region between the listening point and the array plane, as in FIG.

(Comparative example)
Here, the sound pressure distribution by the speaker system of the comparative example will be illustrated and explained. The model diagram shown in FIG. 11 schematically shows a sound beam generated by the principle of delay-and-sum beamformer instead of the tangent method. The shape of the speaker array and the listening point are set in the same manner as in the embodiment.

As shown in FIG. 11, in the comparative example, a beam is generated in a straight line from coordinates (a/2, 0), which is the center point of the first speaker array, toward the intersection point LP2, which is the listening point. has a tilt angle of θ2. Then, the spatial profile of the first speaker array is represented by Equation (8).

(8)

The spatial phase profile of the second speaker array is horizontally inverted with respect to the first speaker array. Here, according to the principle of the delay-and-sum beamformer, the propagation direction of sound waves can be controlled, but the beam length cannot be controlled.

　Fig. 12 shows the sound pressure distribution according to the principle of the delay-and-sum beamformer. Looking at this sound pressure distribution, it can be seen that the sound field is not confined to the area between the listening point LP2 and the array surface, but is widely diffused. This is presumably because the delay-and-sum beamformer method cannot control the beam length.

(Evaluation of robustness)
Next, evaluation results of robustness of the speaker system 10 according to this embodiment will be described. Here, assuming a listener's head, the sound pressure distribution when a rigid sphere as an obstacle is placed near the listening point will be described with reference to the drawings.

FIG. 4 shows the sound pressure distribution when a rigid sphere with a diameter of 0.1 m is placed near the listening point. FIG. 5 shows the sound pressure distribution when a rigid sphere with a diameter of 0.2 m is placed near the listening point. 6 and 7 show the sound pressure distribution when a rigid sphere with a diameter of 0.4 m is placed near the listening point. A rigid sphere with a diameter of 0.2 m is about the size of a listener's head and is close to the size of an acoustic wavelength (0.17 m). Also, a rigid sphere with a diameter of 0.1 m is smaller than the acoustic wavelength.

　As shown in Figures 4, 5, and 6, the larger the rigid sphere, the lower the sound pressure behind it. However, as shown in Fig. 6, even when the diameter of the rigid sphere is increased to about twice the size of the listener's head, the local sound field is successfully confined between the listening point and the array plane. It can be confirmed that Also, as shown in FIG. 7, it can be confirmed that the local sound field is normally confined even in the sound pressure distribution in the three-dimensional space. Thus, the robustness of the speaker system 10 according to this embodiment was confirmed.

Although the speaker system 10 according to the embodiment has been described above, it is needless to say that the speaker system 10 can be implemented in various ways without departing from the gist of the present disclosure. For example, in the above embodiment, as shown in FIG. 1, the spatial phase profile of the first speaker array 12 generates a quadrant arc C1, and the spatial phase profile of the second speaker array 14 generates a quadrant arc C1. C2 was generated, but is not limited to this. That is, an arc-shaped beam shorter than a quadrant may be generated as in the modification shown in FIG.

(Modification)
As shown in FIG. 9, in this modification, the first speaker array 12 is arranged in a range AR1 on the x-axis, which is shorter than in FIG. Also, the second speaker array 14 is arranged in a range AR2 on the x-axis, which is shorter than in FIG.

An arc-shaped beam is generated by the spatial phase profile of the first speaker array 12 set by the first phase setting unit 20 based on the tangent method. In FIG. 9, an arc-shaped beam that is slightly longer than the intersection point LP1 is generated, and the position where the tangent line of the arc at the intersection point LP1 intersects the x-axis is one end of the range AR1. The other end of the range AR1 is a point with coordinates (0, 0).

An arc-shaped beam is generated by the spatial phase profile of the second speaker array 14 set by the second phase setting unit 22 based on the tangent method. In FIG. 9, an arc-shaped beam that is slightly longer than the intersection point LP1 is generated, and the position where the tangent line of the arc at the intersection point LP1 intersects the x-axis is one end of the range AR2. The other end of the range AR2 is set at the intersection of the arc and the x-axis.

As described above, in the modified example, the installation range AR1 of the first speaker array 12 and the installation range AR2 of the second speaker array 14 are arranged so as not to overlap. Even in this case, the local sound field can be confined between the intersection point LP1 and the array surface as in the embodiment.

In addition, although the first speaker array 12 and the second speaker array 14 are fixed in the above embodiment, the present invention is not limited to this, and at least one of the first speaker array 12 and the second speaker array 14 may be configured to be movable. good.

For example, the first speaker array 12 and the second speaker array 14 are supported by a support member (not shown), and driving force such as a motor is used to move the first speaker array 12 and the second speaker array 14 along the x-axis and the y-axis, respectively. A moving mechanism that can move may be provided. In this case, the first speaker array 12 and the second speaker array 14 can be moved at any time according to the position of the desired listening point.

Further, in the above embodiment, as an example, the interval between the first speaker 16 and the second speaker 18 is set to 0.05 m, and the number of the first speaker 16 and the second speaker 18 is set to 21. Not limited. For example, when the listening point is brought closer to the array plane, the number of the first speakers 16 and the second speakers 18 may be reduced so that the size of the arc becomes smaller. Also, the number of the first speakers 16 and the number of the second speakers 18 may be different.

Furthermore, the interval between the first speaker 16 and the second speaker 18 is not limited either. For example, the interval may be set without considering the wavelength of the frequency band of the sound to be output. Further, the intervals between the first speaker 16 and the second speaker 18 may not be equal, but may be arranged at different intervals.

Furthermore, in the above embodiment, the first phase setting section 20 and the second phase setting section 22 have been described as independent setting sections, but the present invention is not limited to this. For example, a configuration in which a function corresponding to the first phase setting unit for setting the phase of the first speaker 16 and a function corresponding to the second phase setting unit for setting the phase of the second speaker 18 are performed by one control unit. good too.

In the above embodiment, as shown in FIG. 1, the beam output from the first speaker array 12 and the beam output from the second speaker array 14 are reversed in the horizontal direction. not. For example, in FIG. 1, arc C1 and arc C2 may be designed to have different shapes. Alternatively, vertically inverted sound beams may be output from two speaker arrays.

Furthermore, in the above embodiment, as shown in FIG. 8, the structure in which the first speaker array 12 and the second speaker array 14 are physically separated has been described, but the present invention is not limited to this. For example, a speaker system in which the first speaker array and the second speaker array are integrally formed may be employed. Even in this case, the first phase setting unit 20 is driven based on the tangential method so that the sound beams are output in the quadrant arc C1 to the plurality of speakers constituting the first speaker array. The phase of the signal is set, and the second phase setting unit outputs sound beams in the shape of an arc C2, which is a quadrant horizontally inverted from the arc C1, to the plurality of speakers forming the second speaker array. If the phase of the driving signal is set based on the tangent line method, the same effect as the above embodiment can be obtained. Also, the functions of the first phase setting section 20 and the second phase setting section may be realized by one phase setting section.
The disclosure of Japanese Patent Application No. 2021-106882 is incorporated herein by reference in its entirety.
All publications, patent applications, and technical standards mentioned herein are to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference. , incorporated herein by reference.

Claims

a first speaker array configured by arranging a plurality of first speakers on a straight line;
a second speaker array configured by arranging a plurality of second speakers on the straight line;
a first phase setting unit for setting a phase of a drive signal based on a tangential method so as to output an arc-shaped sound beam to the plurality of first speakers constituting the first speaker array;
A driving signal based on a tangential method is output to the plurality of second speakers constituting the second speaker array so that sound beams are output in an arc shape that intersects the beams output from the first speaker array. a second phase setting unit that sets the phase of
a speaker system.
The speaker system according to claim 1, wherein the beam output from the first speaker array and the beam output from the second speaker array have a symmetrical shape.
The speaker system according to claim 1 or 2, wherein the number of said first speakers constituting said first speaker array and the number of said second speakers constituting said second speaker array are the same.
The speaker system according to any one of claims 1 to 3, wherein the interval between the adjacent first speakers and the interval between the adjacent second speakers are set to be the same.
The speaker system according to any one of claims 1 to 4, wherein the first speaker and the second speaker are arranged at an interval equal to or less than half the upper limit wavelength in the frequency band of the sound to be output.
The speaker system according to any one of claims 1 to 5, comprising a moving mechanism for moving the position of at least one of the first speaker array and the second speaker array.
The speaker system according to any one of claims 1 to 6, wherein the shape of the beam output from at least one of the first speaker array and the second speaker array can be changed.