Speaker device

Abstract

A speaker device (100) is provided with: a speaker (1) that outputs sound; a speaker (2) that is disposed adjacent to the speaker (1) in a prescribed direction, and outputs sound to a direction that intersects the direction in which the speaker (1) outputs sound; and a phase switching circuit (6) that is capable of switching between a first switching state in which the speaker (1) and the speaker (2) are each input with the same input sound signal, and a second switching state in which one of the speaker (1) and the speaker (2) is input with the input sound signal, and the other of the speaker (1) and the speaker (2) is input with an inverted sound signal that is a sound signal obtained by inverting the phase of the input sound signal.

Description

Technical Field

[0001] This disclosure relates to a loudspeaker device capable of controlling the directivity of a sound field. Background Technology

[0002] Patent document 1 discloses a loudspeaker device in which a pair of loudspeakers are arranged on the same straight line with their backs facing each other and are phase-controlled, thereby controlling the directivity.

[0003] Patent document 2 discloses a loudspeaker device in which a bidirectional open loudspeaker and an omnidirectional closed loudspeaker are arranged in the same straight line in the same direction to control the transmission of sound from the rear.

[0004] Patent document 3 discloses a loudspeaker device in which two groups of a pair of opposing loudspeakers are arranged on the same plane, and sound field control is performed by switching the phase inversion.

[0005] (Existing technical literature)

[0006] (Patent Documents)

[0007] Patent Document 1: Japanese Patent Application Publication No. 8-19089

[0008] Patent Document 2: Japanese Patent Application Publication No. 2011-009990

[0009] Patent Document 3: Japanese Patent Application Publication No. 2013-012991

[0010] In video or web conferences held in a meeting space simply partitioned by partitions, if you don't want outsiders outside the meeting space to hear the participants' voices coming from the speaker system, you can suppress the sound diffusion by reducing the directivity of the speaker system.

[0011] However, when applying the aforementioned conventional loudspeaker devices to video conferencing or web conferencing, in order to control the directivity of the sound field in a three-dimensional manner, it is necessary to construct a large number of loudspeakers in a columnar shape, which presents the problem of making the structure of the loudspeaker device larger and more complex. Summary of the Invention

[0012] This disclosure provides a loudspeaker device that can control the directivity of a sound field with a simple structure.

[0013] The loudspeaker device disclosed herein includes: a first loudspeaker for outputting sound; a second loudspeaker configured adjacent to the first loudspeaker in a predetermined direction and outputting sound in a direction intersecting the direction in which the first loudspeaker outputs sound; and a phase control circuit capable of switching between a first switching state and a second switching state, wherein the first switching state is a state in which the first loudspeaker and the second loudspeaker are respectively input with the same input sound signal, and the second switching state is a state in which one of the first loudspeaker and the second loudspeaker is input with the input sound signal, and the other of the first loudspeaker and the second loudspeaker is input with an inverted sound signal, wherein the inverted sound signal is a sound signal obtained by inverting the phase of the input sound signal.

[0014] The loudspeaker device disclosed herein enables control of the directivity of the sound field with a simple structure. Attached Figure Description

[0015] Figure 1A This is a plan view showing the arrangement of each speaker in the speaker device of Embodiment 1.

[0016] Figure 1B This is a side view showing the arrangement of each speaker in the speaker device of Embodiment 1.

[0017] Figure 2A This is a perspective view showing the upward orientation of the speaker device in Embodiment 1.

[0018] Figure 2B This is a perspective view showing the downward orientation of the speaker device in Embodiment 1.

[0019] Figure 3A This is a diagram showing the electrical structure of the loudspeaker device in Embodiment 1.

[0020] Figure 3B This is an explanatory diagram of the phase relationship of the loudspeaker device in Embodiment 1.

[0021] Figure 4 This is a plan view showing the sound field characteristics of the loudspeaker device in embodiment 1 when it is out of phase.

[0022] Figure 5 This is a side view showing the sound field characteristics of the loudspeaker device in embodiment 1 when it is out of phase.

[0023] Figure 6 This is a plan view showing the sound field characteristics of the loudspeaker device in embodiment 1 when it is in phase.

[0024] Figure 7This is a side view showing the sound field characteristics of the loudspeaker device in embodiment 1 when it is in phase.

[0025] Figure 8A This is a perspective view showing the structure of the loudspeaker device in Embodiment 2.

[0026] Figure 8B This is a plan view showing the structure of the loudspeaker device in Embodiment 2.

[0027] Figure 9 This is a diagram showing the electrical structure of the loudspeaker device in Embodiment 2.

[0028] Figure 10A This is a plan view showing an example of the space in which the speaker device is arranged in Embodiment 2.

[0029] Figure 10B This is a side view showing an example of the space in which the speaker device is arranged in Embodiment 2.

[0030] Figure 11A This is a plan view showing the sound field characteristics in phase when the loudspeaker device is suspended, as in Embodiment 2.

[0031] Figure 11B This is a side view showing the sound field characteristics in phase when the loudspeaker device is suspended, as in Embodiment 2.

[0032] Figure 12A This is a plan view showing the sound field characteristics when the speaker device is placed on a table in the same phase according to Embodiment 2.

[0033] Figure 12B This is a side view showing the sound field characteristics when the speaker device is placed on a table in the same phase according to Embodiment 2.

[0034] Figure 13A This is a plan view showing the sound field characteristics in the case of out-of-phase conditions when a loudspeaker device is suspended, as in Embodiment 2.

[0035] Figure 13B This is a side view showing the sound field characteristics in the case of out-of-phase operation when a loudspeaker device is suspended, as in Embodiment 2.

[0036] Figure 14A This is a plan view showing the sound field characteristics when the speaker device is placed on a table in the case of out-of-phase conditions in Embodiment 2.

[0037] Figure 14B This is a side view showing the sound field characteristics when the speaker device is placed on a table in the case of out-of-phase conditions in Embodiment 2.

[0038] Figure 15A This is a perspective view showing the structure of the loudspeaker device in Embodiment 3.

[0039] Figure 15B This is a plan view showing the structure of the loudspeaker device in Embodiment 3.

[0040] Figure 16 This is a diagram showing the electrical structure of the loudspeaker device in Embodiment 3.

[0041] Figure 17A This is a perspective view showing the upward orientation of the speaker device in Embodiment 3.

[0042] Figure 17B This is a perspective view showing the downward orientation of the speaker device in Embodiment 3.

[0043] Figure 18A This is a plan view showing the sound field characteristics in Embodiment 3 when a loudspeaker device is suspended.

[0044] Figure 18B This is a side view showing the sound field characteristics in Embodiment 3 when a loudspeaker device is suspended.

[0045] Figure 19A This is a plan view showing the sound field characteristics of Embodiment 3 when the speaker device is placed on a table.

[0046] Figure 19B This is a side view showing the sound field characteristics of the speaker device when it is placed on a table in Embodiment 3.

[0047] Figure 20 This diagram illustrates the effect of linearly arraying multiple groups of loudspeaker devices.

[0048] Figure 21 This diagram illustrates the effect of linearly arraying multiple groups of loudspeaker devices.

[0049] Figure 22 This diagram illustrates the effect of linearly arraying multiple groups of loudspeaker devices.

[0050] Figure 23 This is a block diagram showing the structure of the loudspeaker device in Embodiment 4.

[0051] Figure 24 This is a diagram illustrating the directional characteristics of the sound output from the loudspeaker device in Embodiment 4.

[0052] Figure 25 This is a diagram illustrating the directional characteristics of the sound output from the loudspeaker device in Embodiment 4.

[0053] Figure 26 This is a perspective view showing the structure of the loudspeaker device in the modified example. Detailed Implementation

[0054] (Insights, etc., that form the basis of this disclosure)

[0055] Known techniques for controlling the directivity of a sound field include parametric loudspeakers using ultrasound and line array loudspeakers. However, the former requires a large number of loudspeakers and ultrasonic control circuitry, while the latter requires dedicated circuitry for phase control of each loudspeaker.

[0056] Furthermore, phase control using a dipole-type loudspeaker device with a pair of loudspeakers arranged opposite each other is also a known technique. However, in the structure of such a loudspeaker device, multiple loudspeakers need to be arranged three-dimensionally to control the directivity of the stereo sound field, resulting in the problem of having to use a large number of loudspeakers. In addition, in the structure of such a loudspeaker device, when people are present between multiple loudspeakers, sound field chaos occurs, so a sufficient effect cannot be obtained, making it unsuitable for use in small spaces. The inventors discovered the above problems and, in order to solve them, developed the structure of the subject matter of this disclosure.

[0057] Therefore, this disclosure provides a loudspeaker device that can control the directivity of the sound field with a simple structure.

[0058] The embodiments will now be described in detail with reference to the accompanying drawings. However, sometimes necessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters or repetitive descriptions of substantially the same structure may be omitted. This is to avoid unnecessary verbosity in the following description and to facilitate understanding by those skilled in the art.

[0059] Furthermore, the inventors have provided the accompanying drawings and the following description in order to enable those skilled in the art to fully understand this disclosure, but their purpose is not to limit the subject matter of the technical solutions described.

[0060] (Implementation Method 1)

[0061] The following uses Figures 1A to 7 To illustrate implementation method 1.

[0062] [1-1. Structure of a loudspeaker assembly]

[0063] First, refer to Figure 1A as well as Figure 1B To illustrate the loudspeaker device 100 according to Embodiment 1 (see below) Figure 2A as well as Figure 2B The settings of speaker 1 and speaker 2 in (). Figure 1AThis is a plan view showing the arrangement of the speaker 1 and speaker 2 in the speaker device 100 of Embodiment 1. Figure 1B This is a side view showing the arrangement of the speaker 1 and speaker 2 in the speaker device 100 of Embodiment 1.

[0064] The loudspeaker assembly 100 includes a loudspeaker 1 and a loudspeaker 2. Loudspeaker 1 is an example of a first loudspeaker, and loudspeaker 2 is an example of a second loudspeaker. Loudspeaker 1 and loudspeaker 2 have the same characteristics and performance. Figure 1A as well as Figure 1B As shown, loudspeaker 1 and loudspeaker 2 are symmetrically arranged with respect to the virtual plane, i.e., reference plane 3, with one side of the end of each diaphragm approaching or contacting each other.

[0065] In this specification, the direction X, which is the resultant of the sound output direction X1 from speaker 1 and the sound output direction X2 from speaker 2, is referred to as "above". Furthermore, the direction perpendicular to both direction X1 and direction X2 is referred to as "side". Additionally, the direction perpendicular to both above and side is referred to as "front-back direction". The front-back direction is an example of a defined direction. Reference plane 3 is a plane that includes direction X (above) and side.

[0066] Speaker 1 and speaker 2 are configured to be adjacent in the front-to-back direction. Speaker 1 and speaker 2, as... Figure 1B As shown, when viewed from the side, the speakers are symmetrically arranged with respect to the reference plane 3, with the directions of their output (radiated) sound intersecting each other. The angle θ formed by the direction of sound output X1 of speaker 1 and the direction of sound output X2 of speaker 2 ranges from 60° to 120°. This angle θ can be appropriately set according to the desired directivity characteristics.

[0067] Furthermore, speaker 1 and speaker 2 are configured such that the other speaker is positioned in the direction in which one speaker outputs sound. More specifically, "the other speaker is positioned in the direction in which one speaker outputs sound" means, for example, that when speaker 1 is viewed from a direction perpendicular to direction X1, speaker 2 is located further forward than speaker 1 in a direction parallel to direction X1 (the direction of sound output). In other words, speaker 1 and speaker 2 are configured to face each other at an oblique angle. In this specification, this arrangement will be referred to as "acute-angle facing".

[0068] Furthermore, loudspeaker 1 and loudspeaker 2 can be configured in a manner where the angle θ is variable, as described above. By adjusting the angle θ, the directional characteristics in the target frequency band and the range of directional reach can be adjusted.

[0069] Next, refer to Figure 2A as well as Figure 2B The structure of the loudspeaker device 100 will be described. Figure 2A This is a perspective view showing the upward orientation of the speaker device 100 in Embodiment 1. Figure 2B This is a perspective view showing the downward orientation of the speaker device 100 in Embodiment 1.

[0070] like Figure 2A as well as Figure 2B As shown, the loudspeaker device 100 includes a loudspeaker 1, a loudspeaker 2, a housing 4, and a housing 5. The loudspeaker 1 is housed inside the housing 4 and is capable of outputting sound to the outside of the housing 4. The loudspeaker 2 is housed inside the housing 5 and is capable of outputting sound to the outside of the housing 5. The housing 4 and the housing 5 are constructed of enclosed loudspeaker enclosures, for example, formed in a triangular prism shape.

[0071] Frames 4 and 5, with speaker 1 and speaker 2 forming a configuration such that... Figure 1A as well as Figure 1B The speaker unit 100 is configured in the manner shown in the diagram, so that when viewed from the side, it has a valley shape in the center, with the speaker 1 and speaker 2 arranged obliquely opposite each other on the slopes on both sides of the valley. The housing 4 and housing 5 are connected in a manner that fixes their relative positions to each other, but they can also be formed as a single piece. Furthermore, the housing 4 and housing 5 can also be separated, provided that the electrical structure described later is satisfied.

[0072] Furthermore, in this embodiment, the shapes of the frame 4 and the frame 5 are each set as triangular prisms, but they are not limited to this. For example, they can be cuboids or cylinders, as long as the relative arrangement of the speaker 1 and the speaker 2 is in accordance with... Figure 1A as well as Figure 1B As shown, it can be any shape.

[0073] like Figure 2A As shown, the arrangement of the speaker device 100 in which both speaker 1 and speaker 2 are arranged obliquely upward relative to the vertical direction is referred to as "facing upward". On the other hand, the arrangement of the speaker device 100 in which both speaker 1 and speaker 2 are arranged obliquely downward relative to the vertical direction is referred to as "facing downward". When the speaker device 100 is arranged facing downward, the view upward (direction X) from the speaker device 100 is called facing downward (vertical downward).

[0074] Next, while referring to Figure 3A as well as Figure 3B The electrical structure of the loudspeaker device 100 according to Embodiment 1 will be described. Figure 3A This is a diagram showing the electrical structure of the loudspeaker device 100 in Embodiment 1. Figure 3BThis is an explanatory diagram of the phase relationship of the loudspeaker device 100 in Embodiment 1.

[0075] Figure 3A As shown, the loudspeaker device 100, as an electrical structure, includes, in addition to the loudspeaker 1 and loudspeaker 2 described above, an input terminal 7, a phase switching circuit 6, and a switch 8. The phase switching circuit 6 is an example of a phase control circuit.

[0076] Input terminal 7 is the terminal for receiving external audio signals (hereinafter also referred to as "speaker input signal"). Speaker 1 has input terminal 10. Speaker 2 has input terminal 11. A phase switching circuit 6 is electrically connected between input terminal 10 and input terminal 7 of speaker 1.

[0077] The input terminal 10 of the speaker 1 receives an input sound signal or an inverted sound signal from the phase switching circuit 6. The inverted sound signal is a sound signal obtained by inverting the phase of the input sound signal. The speaker 1 outputs sound based on the input sound signal or the inverted sound signal input to the input terminal 10.

[0078] Furthermore, the input sound signal input to the input terminal 7 is directly input to the input terminal 11 of the speaker 2. Specifically, the positive terminal of the input terminal 7 is electrically connected to the positive terminal of the input terminal 11 of the speaker 2, and the negative terminal of the input terminal 7 is electrically connected to the negative terminal of the input terminal 11 of the speaker 2. The speaker 2 outputs sound based on the input sound signal input to the input terminal 11.

[0079] The phase switching circuit 6 switches between the input terminal 7 and the input terminal 10 of the speaker 1 when they are connected with the same polarity or opposite polarities. "Input terminal 7 and the input terminal 10 of the speaker 1 are connected with the same polarity" means that the positive terminal of input terminal 7 is electrically connected to the positive terminal of input terminal 10 of the speaker 1, and the negative terminal of input terminal 7 is electrically connected to the negative terminal of input terminal 10 of the speaker 1. In this case, the phase switching circuit 6 outputs the input audio signal input from input terminal 7 to input terminal 10 of the speaker 1 as is (without phase reversal). Conversely, "Input terminal 7 and the input terminal 10 of the speaker 1 are connected with opposite polarities" means that the positive terminal of input terminal 7 is electrically connected to the negative terminal of input terminal 10 of the speaker 1, and the negative terminal of input terminal 7 is electrically connected to the positive terminal of input terminal 10 of the speaker 1. In this case, the phase switching circuit 6 outputs the inverted audio signal obtained by reversing the phase of the input audio signal input from input terminal 7 to input terminal 10 of the speaker 1.

[0080] Therefore, the phase switching circuit 6 can switch between a first switching state (hereinafter referred to as "in-phase") and a second switching state (hereinafter referred to as "out-of-phase"). In the first switching state, the phase switching circuit 6 outputs the input audio signal received from the input terminal 7 to the input terminal 10 of the speaker 1 as is. Therefore, in the first switching state, the input terminal 10 of the speaker 1 receives the input audio signal output from the phase switching circuit 6, and the input terminal 11 of the speaker 2 receives the input audio signal from the input terminal 7. On the other hand, in the second switching state, the phase switching circuit 6 outputs an inverted audio signal, obtained by inverting the phase of the input audio signal received from the input terminal 7, to the input terminal 10 of the speaker 1. Therefore, in the second switching state, the input terminal 10 of the speaker 1 receives the inverted audio signal output from the phase switching circuit 6, and the input terminal 11 of the speaker 2 receives the input audio signal from the input terminal 7.

[0081] Therefore, as Figure 3B As shown, the phase switching circuit 6 can switch the audio signal input to the input terminal 10 of speaker 1 and the audio signal input to the input terminal 11 of speaker 2 in a manner that is in phase or out of phase. Therefore, the phase switching circuit 6 can switch the audio outputs of speaker 1 and speaker 2 so that they are in phase or out of phase with each other. In other words, speaker 1 and speaker 2 can be electrically connected so that they output audio signals in phase or out of phase with each other.

[0082] The switch 8 accepts user input and outputs a signal corresponding to the input to the phase switching circuit 6. The phase switching circuit 6, based on the signal from the switch 8, can switch between being in phase and being out of phase. Alternatively, the phase switching circuit 6 can be configured as a mechanical switching circuit, and the switch 8 as a mechanical switch, with the phase switching circuit 6 and the switch mechanically linked to switch between being in phase and being out of phase.

[0083] [1-2. Operation of the loudspeaker assembly]

[0084] The operation of the loudspeaker device 100 according to Embodiment 1 will now be described.

[0085] First, refer to Figure 4 as well as Figure 5 The operation of the loudspeaker device 100 when the phase switching circuit 6 is switched to the opposite phase will be explained. Figure 4 This is a plan view showing the sound field characteristics of the loudspeaker device 100 in embodiment 1 when the phase is reversed. Additionally, in Figure 4The diagram shows the sound field characteristics when the phase switching circuit 6 is switched to anti-phase in the loudspeaker device 100, and when the sound is output from the loudspeaker 1 and the loudspeaker 2 from above. Figure 5 This is a side view showing the sound field characteristics of the loudspeaker device 100 in embodiment 1 when the phase is out. Additionally, in Figure 5 The diagram shows the sound field characteristics when the phase switching circuit 6 in the loudspeaker device 100 is switched to anti-phase, and when sound is output from loudspeaker 1 and loudspeaker 2 as viewed from the side.

[0086] exist Figure 4 as well as Figure 5 The sound field curves 12 and 13 shown are contour lines connecting lines with the same sound pressure level. Additionally, in Figure 4 as well as Figure 5 For ease of explanation, only speaker 1 and speaker 2 are shown in the components of speaker device 100.

[0087] Speaker 1 and speaker 2 output sounds that are out of phase with each other. Therefore, on reference plane 3, the sounds that are out of phase overlap. Figure 4 as well as Figure 5 As shown, in this case, the sound field characteristics are such that the sounds output from speaker 1 and speaker 2 on reference plane 3 cancel each other out, so the sound becomes weaker the closer to reference plane 3. Therefore, the sound pressure level of the sound output from speaker device 100 decreases to the side and above the speaker device 100, while the sound pressure level decreases in the front-back direction and diagonally above (…). Figure 1B In the directions X1 and X2, most of the sound output from speaker 1 and speaker 2 propagates rather than cancels each other out.

[0088] Therefore, in the loudspeaker device 100 of this embodiment, by switching the phase switching circuit 6 to the opposite phase, it is possible to output sound at a certain sound pressure in the front-to-back direction, while the sound pressure of the sound output from the side and above is lower than that in the front-to-back direction.

[0089] Next reference Figure 6 as well as Figure 7 The operation of the loudspeaker device 100 when the phase switching circuit 6 switches to the same phase will be explained. Figure 6 This is a plan view showing the sound field characteristics of the loudspeaker device 100 in embodiment 1 when they are in phase. Additionally, in Figure 6 The diagram shows the sound field characteristics when the phase switching circuit 6 is switched to the same phase in the loudspeaker device 100, and when the sound is output from the loudspeaker 1 and the loudspeaker 2 from above. Figure 7 This is a side view showing the sound field characteristics of the loudspeaker device 100 in embodiment 1 when they are in phase. Additionally, in Figure 7 The diagram shows the sound field characteristics when the phase switching circuit 6 is switched to the same phase in the loudspeaker device 100, and when sound is output from loudspeaker 1 and loudspeaker 2, viewed from the side.

[0090] exist Figure 6 as well as Figure 7 The sound field curves 14 and 15 shown are contour lines connecting the same sound pressure level. Additionally, in Figure 6 as well as Figure 7 For ease of explanation, only speaker 1 and speaker 2 are shown in the components of speaker device 100.

[0091] Speaker 1 and speaker 2 output sounds that are in phase with each other. Therefore, the sounds that are in phase with each other overlap on reference plane 3. Figure 6 as well as Figure 7 As shown, in this case, the sound field characteristics are such that the sounds output from speaker 1 and speaker 2 are in phase, so they will not cancel each other out even when they are close to the reference plane 3.

[0092] Therefore, in the loudspeaker device 100 of this embodiment, by switching the phase switching circuit 6 to the same phase, sound can be output to all directions around the loudspeaker device 100.

[0093] Thus, in the speaker device 100 of this embodiment, the directivity of the sound output from the speaker 1 and the speaker 2 can be controlled by the user's operation, so the user can use the speaker device 100 in a way that outputs sound according to the appropriate directivity.

[0094] [1-3. Effects]

[0095] As described above, in this embodiment, the loudspeaker device 100 includes: a loudspeaker 1 that outputs sound; a loudspeaker 2 that is arranged adjacent to the loudspeaker 1 in the front-rear direction and outputs sound in a direction intersecting the direction in which the loudspeaker 1 outputs sound; and a phase switching circuit 6 capable of switching between a first switching state and a second switching state, wherein the first switching state is a state in which the same input sound signal is input to both the loudspeaker 1 and the loudspeaker 2, and the second switching state is a state in which the input sound signal is input to one of the loudspeakers 1 and the loudspeaker 2, and the other loudspeaker is input to an inverted sound signal, wherein the inverted sound signal is a sound signal obtained by inverting the phase of the input sound signal.

[0096] Through the phase switching circuit 6 described above, the sounds output from speaker 1 and speaker 2 can be switched to be in phase or out of phase with each other. When the sounds output from speaker 1 and speaker 2 are switched to be in phase, sound can be output in all directions around the speaker device 100. On the other hand, when the sounds output from speaker 1 and speaker 2 are switched to be out of phase, the sound fields formed by speaker 1 and speaker 2 cancel each other out of phase near the reference plane 3, so the sound pressure can be changed according to the listening position. More specifically, the directivity of the sounds output from speaker 1 and speaker 2 is controlled, and a sound pressure difference can be created between the front-back direction, the side direction, and the top direction of the speaker device 100. Therefore, it is easier to hear the sounds output from speaker 1 and speaker 2 in the front-back direction of the speaker device 100, but it is more difficult to hear the sounds output from speaker 1 and speaker 2 in the side direction of the speaker device 100 than in the front-back direction. As a result, the directivity of the sound field can be controlled with a simple structure.

[0097] Furthermore, in this embodiment, the angle formed by the direction of sound output from speaker 1 and the direction of sound output from speaker 2 is in the range of 60° to 120°.

[0098] As described above, when the sounds output from speaker 1 and speaker 2 are switched to opposite phase, the sound fields formed by speaker 1 and speaker 2 can be effectively canceled out of each other near the reference plane 3.

[0099] Furthermore, in this embodiment, speaker 1 and speaker 2 are configured such that the other speaker is configured in the direction in which one speaker outputs sound.

[0100] Through the above, the overall size of the speaker device 100 can be reduced to a smaller size.

[0101] Furthermore, in this embodiment, the speaker device 100 also includes an input terminal 7 for receiving input audio signals. The phase switching circuit 6 can switch the output to either output the input audio signal received from the input terminal 7 as is, or output an inverted audio signal obtained by inverting the phase of the input audio signal. In the first switching state, the input audio signal output from the phase control circuit 6 is input to the speaker 1, and the input audio signal from the input terminal 7 is input to the speaker 2. In the second switching state, the inverted audio signal output from the phase switching circuit 6 is input to the speaker 1, and the input audio signal from the input terminal 7 is input to the speaker 2.

[0102] Through the above, the phase switching circuit 6 can easily switch between the first switching state and the second switching state.

[0103] (Implementation Method 2)

[0104] Next, utilize Figures 8A to 14B The second implementation method will be described below.

[0105] [2-1. Structure of a loudspeaker assembly]

[0106] refer to Figure 8A as well as Figure 8B The structure of the loudspeaker device 200 according to Embodiment 2 will be described. Figure 8A This is a perspective view showing the structure of the loudspeaker device 200 in Embodiment 2. Figure 8B This is a plan view showing the structure of the loudspeaker device 200 in Embodiment 2. Furthermore, in the various embodiments shown below, the same reference numerals are used for components that are the same as those in Embodiment 1 described above, and their descriptions are omitted.

[0107] In the loudspeaker device 200 according to Embodiment 2, the difference from the loudspeaker device 100 according to Embodiment 1 is that the loudspeaker device 100 according to Embodiment 1 is configured as two groups, arranged in a linear array on the side. More specifically, as Figure 8A as well as Figure 8B As shown, the loudspeaker device 200 includes loudspeaker device 100a and loudspeaker device 100b.

[0108] The structures of speaker devices 100a and 100b are the same as those of speaker device 100 according to Embodiment 1. That is, speaker device 100a includes speaker 1a, speaker 2a, frame 4a, and frame 5a. Speaker device 100b includes speaker 1b, speaker 2b, frame 4b, and frame 5b.

[0109] In the loudspeaker assembly 200, a group of loudspeakers 1a and 2a facing each other at acute angles, and a group of loudspeakers 1b and 2b facing each other at acute angles, are arranged in a linear array on the side. Furthermore, loudspeakers 1a and 1b will sometimes be collectively referred to as "loudspeaker 1", and loudspeakers 2a and 2b will sometimes be collectively referred to as "loudspeaker 2".

[0110] Next, refer to Figure 9 The electrical structure of the loudspeaker device 200 according to Embodiment 2 will be described. Figure 9 This is a perspective view showing the electrical structure of the loudspeaker device 200 in Embodiment 2.

[0111] like Figure 9As shown, the loudspeaker device 200 also has the electrical structure of the loudspeaker device 100 according to Embodiment 1, which includes two sets. Specifically, loudspeaker device 100a, as its electrical structure, includes, in addition to the aforementioned loudspeakers 1a and 2a, an input terminal 7a, a phase switching circuit 6a, and a switching switch 8a. Loudspeaker device 100b, as its electrical structure, includes, in addition to the aforementioned loudspeakers 1b and 2b, an input terminal 7b, a phase switching circuit 6b, and a switching switch 8b.

[0112] Speaker 1a has an input terminal 10a. Speaker 2a has an input terminal 11a. Speaker 1b has an input terminal 10b. Speaker 2b has an input terminal 11b. Speaker 1a and speaker 2a are electrically connected in a manner that enables them to output sounds in the same or opposite phase. Similarly, speaker 1b and speaker 2b are electrically connected in a manner that enables them to output sounds in the same or opposite phase.

[0113] A signal from sound source L (hereinafter referred to as "signal L") is input to input terminal 7a of loudspeaker device 100a, and a signal from sound source R (hereinafter referred to as "signal R") is input to input terminal 7b of loudspeaker device 100b. Signal L and signal R are respectively assigned, for example, signals from the L channel and R channel of a stereo sound source.

[0114] In addition, in this embodiment, signals L and R are each assigned signals of the L channel and R channel of a stereo sound source, respectively. However, they do not necessarily have to be signals of a stereo sound source. For example, signals of a mono sound source can be assigned the same signal as signals L and R.

[0115] [2-2. Operation of the loudspeaker assembly]

[0116] The operation of the loudspeaker device 200 according to Embodiment 2 will now be described.

[0117] The loudspeaker device 200 basically has a structure in which two sets of the loudspeaker device 100 according to Embodiment 1 are arranged in a linear array on the side, so it has the same sound field characteristics as the loudspeaker device 100 according to Embodiment 1. Next, as an example of a specific space in which the loudspeaker device 200 is arranged, a meeting space will be used for explanation.

[0118] refer to Figure 10A as well as Figure 10B The space in which the loudspeaker unit 200 is configured will be described. Figure 10A This is a plan view showing an example of the space in which the loudspeaker device 200 is arranged in Embodiment 2. Figure 10B This is a side view showing an example of the space in which the loudspeaker device 200 is arranged in Embodiment 2.

[0119] The speaker unit 200 is configured in a space, such as a meeting space set up in an open space. Figure 10A As shown, the meeting space is surrounded on three sides by a sound-absorbing partition 30, with the remaining side open as an entrance / exit. Therefore, compared to the three sides surrounded by the partition 30, the entrance / exit on the open side without the partition 30 allows sound to propagate more easily to the outside of the meeting space.

[0120] Furthermore, the meeting space surrounded by partition 30 has no roof, and the upper part of partition 30 is supported by a plurality of spaced-apart crossbeams 39. Additionally, for ease of explanation, in Figure 10A Only one crossbeam, 39, is shown in the diagram. (For example...) Figure 10B As shown, there are gaps between the partition 30 and the ceiling 29, through which sound can easily propagate to the outside of the meeting space.

[0121] In this meeting space, four participants (23-26) sit at table 27 and participate in video conferences or web conferences. Outsider 28, who does not participate in video conferences or web conferences in the meeting space, can pass through the passageway next to the entrance / exit of partition 30 outside the meeting space.

[0122] Next reference Figure 11A as well as Figure 11B In the aforementioned meeting space, the speaker unit 200 is suspended from the crossbeam 39, and the phase switching circuits 6a and 6b (see reference) are installed. Figure 9 The following explanation will cover the case where all phases are switched to the same phase. Figure 11A This is a plan view showing the sound field characteristics in phase when the loudspeaker device 200 is suspended, according to Embodiment 2. Figure 11B This is a side view showing the sound field characteristics in phase when the loudspeaker device 200 is suspended, as in Embodiment 2. Furthermore, for ease of explanation, in... Figure 11A The illustration of crossbeam 39 is omitted.

[0123] like Figure 11A as well as Figure 11B As shown, the speaker unit 200 is positioned relative to the upper crossbeam 39 above the center of the table 27, facing downwards (towards...). Figure 8A The speaker unit 200 shown is installed in a manner where the orientation is reversed (vertical orientation is used for comparison). Furthermore, the speaker unit 200 is positioned such that meeting participants 23-26 are located in this front-to-back direction (in...). Figure 11A as well as Figure 11B It is installed in a left-right direction. At this time, the side of the speaker device 200 faces the entrance / exit of the partition 30. Figure 11A as well as Figure 11BThe sound field curves 31 and 32 shown are contour lines connecting the same sound pressure.

[0124] The speaker device 200 is used as a conference speaker to output sound from a remote location in video conferencing or web conferencing. In the speaker device 200, the phase switching circuits 6a and 6b are switched to be in phase so that speakers 1a and 2a output sound of the same phase, and speakers 1b and 2b output sound of the same phase.

[0125] like Figure 11A As shown in the sound field curve 31, the sound of the conference output from the loudspeaker device 200 propagates from the open side entrance without partition 30 to an outsider 28, who is not part of the conference participants 23-26, and can easily hear the conference sound. Furthermore, as... Figure 11B As shown in the sound field curve 32, the sound of the meeting output from the speaker device 200 also propagates to the outside of the meeting space through the gap between the ceiling 29 and the partition 30, making it possible to hear the sound of the meeting outside the meeting space.

[0126] Next reference Figure 12A as well as Figure 12B The following explanation addresses the situation where the speaker device 200 is placed on a table (table 27) in the aforementioned meeting space, and both phase switching circuits 6a and 6b are switched to the same phase. Figure 12A This is a plan view showing the sound field characteristics when the speaker device 200 is placed on a table in the same phase according to Embodiment 2. Figure 12B This is a side view showing the sound field characteristics in phase when the speaker device 200 is placed on a table, as in Embodiment 2. Furthermore, for ease of explanation, in... Figure 12A The illustration of crossbeam 39 is omitted.

[0127] like Figure 12A as well as Figure 12B As shown, the speaker unit 200 is positioned in the center of the table 27 and faces upwards. Figure 8A The speaker device 200 is configured in such a way that the meeting participants 23-26 are positioned in the front-to-back direction (as shown in the diagram). Figure 12A as well as Figure 12B It is installed in a left-right direction. At this time, the side of the speaker device 200 faces the entrance / exit of the partition 30. Figure 12A as well as Figure 12B The sound field curves 33 and 34 shown are contour lines connecting the same sound pressure.

[0128] loudspeaker unit 200 and Figure 11A as well as Figure 11B The same suspension configuration is used as a conference loudspeaker to output sound from a remote location in video conferencing or web conferencing. In the loudspeaker device 200, phase switching circuits 6a and 6b are switched to be in phase so that loudspeakers 1a and 2a output sound of the same phase, and loudspeakers 1b and 2b also output sound of the same phase.

[0129] like Figure 12A As shown in sound field curve 33, the sound of the conference output from loudspeaker device 200 propagates from the open side entrance without partition 30 to an outsider 28, who is not part of the conference participants 23-26, and can easily hear the conference sound. Furthermore, as... Figure 12B As shown in the sound field curve 34, the sound of the meeting output from the loudspeaker device 200 is also propagated to the outside of the meeting space through the space between the ceiling 29 and the partition 30, making it possible to hear the sound of the meeting from outside the meeting space.

[0130] Next reference Figure 13A as well as Figure 13B The following describes the case in which the speaker device 200 is suspended from the crossbeam 39 in the aforementioned meeting space, and the phase switching circuits 6a and 6b are both switched to opposite phase. Figure 13A This is a plan view showing the sound field characteristics when the loudspeaker device 200 is suspended in the opposite phase in Embodiment 2. Figure 13B This is a side view showing the sound field characteristics under out-of-phase conditions in Embodiment 2 with the loudspeaker device 200 suspended. Furthermore, for ease of explanation, in Figure 13A The illustration of crossbeam 39 is omitted.

[0131] like Figure 13A as well as Figure 13B As shown, the speaker unit 200 is mounted downwards relative to the crossbeam 39 above the center of the table 27. Furthermore, the speaker unit 200 is positioned such that meeting participants 23-26 are located in the front-to-back direction (in... Figure 13A as well as Figure 13B It is installed in a left-right direction. At this time, the side of the speaker device 200 faces the entrance / exit of the partition 30. Figure 13A as well as Figure 13B The sound field curves 35 and 36 shown are contour lines connecting the same sound pressure.

[0132] The speaker device 200 is used as a conference speaker to output sound from a remote location in video conferencing or web conferencing. In the speaker device 200, the phase switching circuits 6a and 6b are both switched to anti-phase so that anti-phase sound is output from speakers 1a and 2a, and also from speakers 1b and 2b.

[0133] like Figure 13A As shown, the speaker device 200 operates in reverse phase (i.e., phase switching circuits 6a and 6b are both switched to reverse phase), thereby the sound output from the speaker device 200 is as follows: Figure 4 As shown, the directivity is controlled, resulting in the sound field characteristics shown in sound field curve 35. Therefore, conference participants 23-26 located in the front-to-back direction of the loudspeaker device 200 can easily hear the conference sound output from the loudspeaker device 200, but outsiders 28 located to the side of the loudspeaker device 200 have difficulty hearing the conference sound output from the loudspeaker device 200.

[0134] In addition, such as Figure 13B As shown, the sound output from the speaker device 200 is as follows: Figure 5 As shown, the directivity is controlled, resulting in the sound field characteristics shown in sound field curve 36. Looking upwards from the speaker unit 200 (at... Figure 13B In the setup shown, sound propagating directly below the speaker unit 200 is suppressed, and the sound is also suppressed from being reflected off the table 27 and propagating outside the meeting space through the gap between the ceiling 29 and the partition 30. Therefore, meeting participants 23-26 can easily hear the meeting sound output from the speaker unit 200, and sound propagating outside the meeting space through the gap between the ceiling 29 and the partition 30 is suppressed.

[0135] Next reference Figure 14A as well as Figure 14B The following explanation addresses the situation where the speaker device 200 is placed on a table (table 27) in the aforementioned meeting space, and both phase switching circuits 6a and 6b are switched to opposite phase. Figure 14A This is a plan view showing the sound field characteristics when the speaker device 200 is placed on a table in the case of out-of-phase conditions in Embodiment 2. Figure 14B This is a side view showing the sound field characteristics in reverse phase when the speaker device 200 is placed on a table, as in Embodiment 2. Furthermore, for ease of explanation, in Figure 14A The illustration of crossbeam 39 is omitted.

[0136] like Figure 14A as well as Figure 14BAs shown, the speaker unit 200 is arranged in the center of the table 27, facing upwards. Furthermore, the speaker unit 200 is positioned such that meeting participants 23-26 are located in the front-to-back direction (in... Figure 14A as well as Figure 14B It is installed in a left-right direction. At this time, the side of the speaker device 200 faces the entrance / exit of the partition 30. Figure 14A as well as Figure 14B The sound field curves 37 and 38 shown are contour lines connecting the same sound pressure.

[0137] The speaker device 200 is used as a conference speaker to output sound from a remote location in video conferencing or web conferencing. In the speaker device 200, the phase switching circuits 6a and 6b are switched to opposite phase so that the speakers 1a and 2a output sound that is out of phase with each other, and the speakers 1b and 2b also output sound that is out of phase with each other.

[0138] like Figure 14A As shown, the speaker device 200 operates in reverse phase (i.e., phase switching circuits 6a and 6b are both switched to reverse phase), thereby the sound output from the speaker device 200 is as follows: Figure 4 As shown, the directivity is controlled, resulting in the sound field characteristics shown in sound field curve 37. Therefore, conference participants 23-26 located in the front-to-back direction of the loudspeaker device 200 can easily hear the conference sound output from the loudspeaker device 200, but outsiders 28 located to the side of the loudspeaker device 200 have difficulty hearing the conference sound output from the loudspeaker device 200.

[0139] In addition, such as Figure 14B As shown, the sound output from the speaker device 200 is as follows: Figure 5 As shown, the directivity is controlled, resulting in the sound field characteristics shown in sound field curve 38. Therefore, meeting participants 23-26 can easily hear the meeting sound output from the speaker device 200, and can suppress sound propagating from the gap between the ceiling 29 and the partition 30 to the outside of the meeting space.

[0140] As described above, in the case of video conferencing or web conferencing in a meeting space, in order to suppress the propagation of meeting sound output from speaker device 200 to the outside of the meeting space, the user can adjust switch 8a and switch 8b (see reference) Figure 9 This can be done by operating the phase switching circuits 6a and 6b to switch them to opposite phase.

[0141] On the other hand, when enjoying music in the meeting space, the sound of the music output from the speaker device 200 can be transmitted outside the meeting space without any problem. Therefore, the user can switch the phase switching circuits 6a and 6b to the same phase by operating the switch 8a and switch 8b.

[0142] [2-3. Effects]

[0143] As described above, in this embodiment, multiple groups consisting of loudspeakers 1 and loudspeakers 2 are provided. The multiple groups of loudspeakers 1 and loudspeakers 2 are arranged in a linear array in a direction intersecting the front-back direction.

[0144] As described above, the loudspeaker device 100 of Embodiment 1 is arranged in multiple groups in a linear array on the side, that is, in a direction intersecting the front and rear directions, thereby increasing the sharpness, directional range, and directional distance of the directional characteristics. In the loudspeaker device 200 of this embodiment, two groups of the loudspeaker device 100 of Embodiment 1 are arranged in a linear array on the side. However, by changing the number of loudspeaker devices 100 arranged, the sharpness, directional range, and directional distance of the directional characteristics can be adjusted.

[0145] Furthermore, by controlling the directivity of the sound output from the loudspeaker device 200, a sound pressure difference can be created between the front-to-back, side, and top directions. This directivity is particularly pronounced in the human voice frequency band, specifically the 500Hz–2kHz band, thereby creating a sound pressure difference of 15–20 dB between the listening positions of meeting participants 23–26 and the listening position of outsider 28.

[0146] Therefore, it is possible to suppress the propagation of sound from an outsider 28 to the entrance / exit side of the partition 30, as well as the propagation of sound leaking from the gap between the ceiling 29 and the partition 30.

[0147] Therefore, in video conferencing or web conferencing, it is possible to reduce the leakage of conference sound output from speaker device 200 to the outside of the conference space without the need to use headphones, and the conference can be conducted without reducing the volume of speaker device 200.

[0148] Furthermore, when a speaker device is typically positioned downwards relative to the crossbeam 39, sound output from the speaker device is reflected and diffused on the upper surface of the table 27, or sound output from the speaker device is picked up by a conference microphone or the like positioned on the table 27, resulting in positive feedback and howling. However, in the speaker device 200 of this embodiment, the sound pressure level of sound propagating directly downwards (above view from the speaker device 200) from the speaker device 200 is relatively lower due to directional control. Therefore, sound output from the speaker device 200 is less likely to propagate to the table 27, suppressing the diffusion of sound reflected from the upper surface of the table 27 and howling through the conference microphone.

[0149] (Implementation Method 3)

[0150] Next, utilize Figures 15A to 19B The third implementation method will be described below.

[0151] [3-1. Structure of a loudspeaker assembly]

[0152] While referring Figure 15A as well as Figure 15B The structure of the loudspeaker device 300 according to Embodiment 3 will be explained. Figure 15A This is a perspective view showing the structure of the loudspeaker device 300 in Embodiment 3. Figure 15B This is a plan view showing the structure of the loudspeaker device 300 in Embodiment 3.

[0153] In the loudspeaker device 300 according to Embodiment 3, the difference from the loudspeaker device 200 according to Embodiment 2 is that on both sides of the loudspeaker device 200 in Embodiment 2, one loudspeaker device 100 from Embodiment 1 is also arranged. That is, the loudspeaker device 300 in Embodiment 3 has a structure in which four groups of loudspeaker devices 100 from Embodiment 1 are arranged in a linear array on the sides in a direction that intersects a predetermined direction.

[0154] like Figure 15A as well as Figure 15B As shown, the loudspeaker device 300 includes loudspeaker device 100a, loudspeaker device 100b, loudspeaker device 100c, and loudspeaker device 100d. Loudspeaker device 100a includes loudspeaker 1a, loudspeaker 2a, frame 4a, and frame 5a. Loudspeaker device 100b includes loudspeaker 1b, loudspeaker 2b, frame 4b, and frame 5b. Loudspeaker device 100c includes loudspeaker 1c, loudspeaker 2c, frame 4c, and frame 5c. Loudspeaker device 100d includes loudspeaker 1d, loudspeaker 2d, frame 4d, and frame 5d.

[0155] In the loudspeaker device 300, groups of loudspeakers 1a and 2a facing each other at acute angles, groups of loudspeakers 1b and 2b facing each other at acute angles, groups of loudspeakers 1c and 2c facing each other at acute angles, and groups of loudspeakers 1d and 2d facing each other at acute angles are arranged in a linear array on the side. Two pairs of loudspeakers arranged at both ends of the side of the loudspeaker device 300, namely groups of loudspeakers 1c and 2c and groups of loudspeakers 1d and 2d, are used to output masking sound. Loudspeakers 1a and 1b are examples of first loudspeakers. Loudspeakers 2a and 2b are examples of second loudspeakers. Loudspeakers 1c, 2c, 1d, and 2d are examples of third loudspeakers.

[0156] Next reference Figure 16 The electrical structure of the loudspeaker device 300 in Embodiment 3 will be described. Figure 16 This is a diagram showing the electrical structure of the loudspeaker device 300 in Embodiment 3.

[0157] like Figure 16 As shown, the electrical structures of the four loudspeaker devices 100a to 100d are the same as those of the loudspeaker device 100 according to Embodiment 1, so detailed descriptions are omitted. Loudspeaker device 100a receives a signal from sound source L (hereinafter referred to as "signal L"), loudspeaker device 100b receives a signal from sound source R (hereinafter referred to as "signal R"), loudspeaker device 100c receives a signal from masking sound source ML (hereinafter referred to as "signal ML"), and loudspeaker device 100d receives a signal from masking sound source MR (hereinafter referred to as "signal MR").

[0158] Speaker devices 100c and 100d each output masking sounds based on signals ML and MR (hereinafter collectively referred to as "masking signals"). Signals L and R can each be assigned to the L channel and R channel of a stereo sound source, respectively. Signals ML and MR are sound signals used to output masking sounds designed to make the sounds output by speaker devices 100a and 100b difficult to hear. Masking sounds can be, for example, white noise, or natural sounds such as the sound of flowing water or birdsong. Alternatively, masking sounds can include frequencies in the same frequency band as human voices. Signals ML and MR can be assigned to the same sound source.

[0159] For loudspeaker devices 100c and 100d, it is preferable to output masking sounds with a lower sound pressure level than a predetermined value when the sounds output by loudspeaker devices 100a and 100b are heard in the front-rear direction. This predetermined value refers to a value smaller than the difference between the front-rear sound pressure level and the lateral sound pressure level when loudspeaker devices 100a and 100b output sounds in opposite phase. In other words, it is preferable to set the sound pressure level of the sounds output by loudspeaker devices 100c and 100d such that it is lower than the sound pressure level when the sounds output by loudspeaker devices 100a and 100b are heard in the front-rear direction, and higher than the sound pressure level when the sounds output by loudspeaker devices 100a and 100b are heard in the lateral direction. In other words, it is preferable to input input sound signals to speaker devices 100a and 100b and input masking signals to speaker devices 100c and 100d in such a way that the sound reproduction device configured outside the speaker device 300 satisfies the aforementioned sound pressure conditions.

[0160] Next, refer to... Figure 17A as well as Figure 17B The speaker device 300 is described in detail. Figure 17A This is a diagram showing the upward orientation of the speaker device 300 in Embodiment 3. Figure 17B This is a diagram showing the downward orientation of the speaker device 300 in Embodiment 3.

[0161] For example, in the case of a speaker device 300 being installed on a table or other table, such as Figure 17A As shown, the speaker unit 300 is positioned facing upwards. On the other hand, for example, if the speaker unit 300 is mounted on a beam or similar object, such as... Figure 17B As shown, the speaker unit 300 is positioned downwards.

[0162] [3-2. Operation of the loudspeaker assembly]

[0163] The operation of the loudspeaker device 300 according to Embodiment 3 will now be explained.

[0164] First refer to Figure 18A as well as Figure 18B Regarding the meeting space mentioned above (refer to...) Figure 10A as well as Figure 10B The case where the loudspeaker unit 300 is suspended on the crossbeam 39 will be described. Figure 18A This is a plan view showing the sound field characteristics in Embodiment 3 with the loudspeaker device 300 suspended. Figure 18BThis is a side view showing the sound field characteristics in Embodiment 2 with the loudspeaker device 300 suspended. Furthermore, for ease of explanation, in Figure 18A The illustration of crossbeam 39 is omitted.

[0165] like Figure 18A as well as Figure 18B As shown, the speaker unit 300 is positioned relative to the crossbeam 39 above the center of the table 27, facing downwards. Figure 17B The speaker unit 300 is installed in the manner shown in the orientation. Furthermore, the speaker unit 300 is positioned such that meeting participants 23-26 are located in this front-to-back direction (in...). Figure 18A as well as Figure 18B It is installed in a left-right orientation. At this time, the side of the speaker unit 300 faces the entrance / exit of the partition 30. Figure 18A as well as Figure 18B The sound field curves 46 and 47, represented by dashed lines, are contour lines connecting the same sound pressure levels in the sounds output from loudspeaker device 100a and loudspeaker device 100b. Figure 18A as well as Figure 18B The sound field curves 51 and 52, represented by dashed lines, are contour lines connecting the same sound pressure levels in the masked sounds output from the loudspeaker device 100c and loudspeaker device 100d, respectively.

[0166] The two central speaker units 100a and 100b of speaker unit 300 are used as conference speakers to output sound (conference sound) from a remote location in video conferencing or web conferencing. Speakers 1a and 2a of speaker unit 100a output sound that is out of phase with each other. Speakers 1b and 2b of speaker unit 100b also output sound that is out of phase with each other.

[0167] On the other hand, the two sets of speaker devices 100c and 100d at both ends of the speaker device 300 output masking sounds in phase. Thus, the speaker devices 100c and 100d form a wide-range sound field based on masking sounds around the speaker device 300.

[0168] like Figure 18A As shown, speaker devices 100a and 100b, used as conference loudspeakers in speaker device 300, operate in opposite phase. The sound output from speaker devices 100a and 100b is as follows: Figure 4As shown, the directivity is controlled, resulting in the sound field characteristics shown in sound field curve 46. Therefore, conference participants 23-26 located in the front-to-back direction of loudspeaker devices 300 (loudspeaker devices 100a and 100b) can easily hear the conference sound output from loudspeaker devices 100a and 100b, but outsiders 28 located to the side of loudspeaker devices 300 have difficulty hearing the conference sound output from loudspeaker devices 100a and 100b.

[0169] In addition, such as Figure 18B As shown, the sound output from speaker devices 100a and 100b is as follows: Figure 5 As shown, the directivity is controlled, resulting in the sound field characteristics represented by sound field curve 47. Therefore, meeting participants 23-26 can easily hear the meeting sounds output from loudspeaker devices 100a and 100b, and can suppress the meeting sounds propagating to the outside of the meeting space from the gap between the ceiling 29 and the partition 30.

[0170] Speaker devices 100c and 100d, which output masking sound in speaker device 300, operate in phase. The sound output from speaker devices 100c and 100d is as follows: Figure 6 as well as Figure 7 As shown, the directivity is controlled, resulting in the sound field characteristics represented by sound field curves 51 and 52. The masking sound is in phase and has a wide directivity, so it can propagate to the outside of the partition 30. Therefore, the masking sound can be heard not only by the meeting participants 23-26, but also by the outsider 28.

[0171] Next, refer to... Figure 19A as well as Figure 19B The speaker unit 300 is placed on a table (table 27) in the aforementioned meeting space. Figure 19A This is a plan view showing the sound field characteristics of the speaker device 300 when it is placed on a table in Embodiment 3. Figure 19B This is a side view showing the sound field characteristics of the speaker device 300 when it is placed on a table in Embodiment 3.

[0172] Figure 19A as well as Figure 19B The sound field curves 48 and 49, each represented by a dashed line, are contour lines connecting the same sound pressure level in the sound output from loudspeaker device 100a and loudspeaker device 100b. Figure 19A as well as Figure 19BThe sound field curves 53 and 54, each represented by a dashed line, are contour lines connecting the same sound pressure level in the masked sound output by the loudspeaker device 100c and loudspeaker device 100d, respectively.

[0173] The two sets of speaker devices 100a and 100b at the center of speaker device 300 are used as conference speakers to output sound (conference sound) from a remote location, such as in video conferencing or web conferencing. Speakers 1a and 2a of speaker device 100a output sounds that are out of phase with each other. Speakers 1b and 2b of speaker device 100b also output sounds that are out of phase with each other. On the other hand, the two sets of speaker devices 100c and 100d at both ends of speaker device 300 output masking sounds that are in phase with each other. Thus, speaker devices 100c and 100d form a wide-range masking sound field around speaker device 300.

[0174] like Figure 19A As shown, speaker devices 100a and 100b, used as conference loudspeakers in speaker device 300, operate in opposite phase. The sound output from speaker devices 100a and 100b is as follows: Figure 4 As shown, the directivity is controlled, resulting in the sound field characteristics shown in sound field curve 48. Therefore, conference participants 23-26 located in the front-to-back direction of the loudspeaker devices 300 (loudspeaker devices 100a and 100b) can easily hear the conference sound output from loudspeaker devices 100a and 100b, but outsiders 28 located to the side of the loudspeaker devices 300 have difficulty hearing the conference sound output from loudspeaker devices 100a and 100b.

[0175] In addition, such as Figure 19B As shown, the sound output from speaker devices 100a and 100b is as follows: Figure 5 As shown, the directivity is controlled, resulting in the sound field characteristics represented by sound field curve 49. Therefore, meeting participants 23-26 can easily hear the meeting sounds output from loudspeaker devices 100a and 100b, and the meeting sounds propagating to the outside of the meeting space from the gap between the ceiling 29 and the partition 30 can be suppressed.

[0176] Speaker devices 100c and 100d, which output masking sound in speaker device 300, operate in phase. The sound output from speaker devices 100c and 100d is as follows: Figure 6 as well as Figure 7As shown, the directivity is controlled, resulting in the sound field characteristics represented by sound field curves 53 and 54. The masking sound is in phase and has a wide directivity, so it can propagate to the outside of the partition 30. Therefore, the masking sound can be heard not only by the meeting participants 23-26, but also by the outsider 28.

[0177] Therefore, the conference sound, along with the masking sound output from loudspeaker devices 100c and 100d, propagates in the front-to-back direction of loudspeaker device 300, so that conference participants 23-26 can hear the conference sound along with the masking sound. The sound pressure level of the conference sound is higher in the front-to-back direction than in the side directions, so the conference sound is less masked by the masking sound compared to the side directions.

[0178] On the other hand, the sound of the meeting propagates to the sides of the loudspeaker device 300 with a lower sound pressure level than in the front-to-back direction, making it difficult for an outsider 28 to hear the meeting. Furthermore, masking sounds propagate to the sides of the loudspeaker device 300 with the same sound pressure level as in the front-to-back direction, but since the sound pressure level of the meeting is lower than in the front-to-back direction, the meeting is masked to a greater extent than in the front-to-back direction. Therefore, the loudspeaker device 300, which outputs masking sounds, can further amplify the difference in the ease of hearing the meeting sound depending on the listening position.

[0179] Furthermore, regarding the sound pressure level of the masking sound output by speaker devices 100c and 100d, it is preferable to set the sound pressure level of the masking sound to be lower than the sound pressure level when listening to the conference sound output from speaker devices 100a and 100b from a position in the front-back direction relative to speaker devices 100a and 100b, and higher than the sound pressure level when listening to the conference sound output from speaker devices 100a and 100b from a position to the side relative to speaker devices 100a and 100b. In this case, conference participants 23-26 located in the front-back direction relative to speaker device 300 can listen to the conference sound output from speaker devices 100a and 100b with a higher sound pressure level than the masking sound output by speaker devices 100c and 100d, thus enabling them to hear the conference sound more clearly. On the other hand, for an outsider 28 located to the side of the loudspeaker 300, the sound pressure of the conference sound output from loudspeaker 100a and loudspeaker 100b is lower than that in the front-to-back direction, and therefore the masking sound output from loudspeaker 100c and loudspeaker 100d is heard at a higher pressure than the conference sound, making it difficult to hear the conference sound.

[0180] As explained above, the speaker device 300 of this embodiment is positioned either downwards above the crossbeam 39 above the center of the table 27, or upwards in the center of the table 27, and is used as a conference speaker. Speaker devices 100a and 100b output the directional sound of the conference into the conference space. Speaker devices 100c and 100d output masking sound in all directions around the conference space.

[0181] Four meeting participants, 23-26, are seated in front of table 27, positioned in front of and behind the loudspeaker unit 300. An outsider, 28, can pass near the entrance / exit on the open side of partition 30, i.e., to the side of the loudspeaker unit 300. Under these conditions, by controlling the directional characteristics, a sound pressure level difference of 15-20 dB can be created between the listening positions of meeting participants 23-26 and outsider 28, targeting the human sound frequency band of 500 Hz to 2 kHz.

[0182] Furthermore, speaker devices 100c and 100d are respectively arranged on both sides of speaker devices 100a and 100b in the front-rear direction, and masking sounds are output from speaker devices 100c and 100d. Speaker devices 100c and 100d use ambient sounds such as natural sounds of the same phase as masking sounds, and output them at a sound pressure level 10-15 dB lower than the sound output by speaker 1 and speaker 2 of speaker devices 100a and 100b. Therefore, outside the meeting space, the sound pressure level of the meeting sound output from speaker devices 100a and 100b is lower than the sound pressure level of the masking sounds output from speaker devices 100c and 100d.

[0183] Thus, it is possible to suppress the transmission of meeting sounds from the entrance / exit side of partition 30 to outsiders 28 other than meeting participants 23-26, and to prevent leakage of meeting space to the outside from the gap between ceiling 29 and partition 30.

[0184] Therefore, by using the speaker device 300 of this embodiment, meeting participants 23 to 26 can conduct a meeting without having to use headphones or reduce the volume of the speaker in order to prevent the sound of the meeting from leaking to the outside of the meeting space.

[0185] [3-3. Effect]

[0186] As described above, in this embodiment, the loudspeaker device 300 further includes loudspeaker 1c, loudspeaker 1d, loudspeaker 2c and loudspeaker 2d, which are arranged adjacent to loudspeaker 1a, loudspeaker 1b, loudspeaker 2a and loudspeaker 2b in a direction intersecting the front-back direction, and output sound based on a masking signal that is different from the loudspeaker input signal (input sound signal and inverted sound signal).

[0187] As described above, masked sound is output in the front-rear direction and the side direction intersecting the front-rear direction of the speaker device 300. In the front-rear direction of the speaker device 300, it is possible to hear the sound output from speaker 1a, speaker 1b, speaker 2a and speaker 2b, but it is more difficult to hear these sounds in the side direction of the speaker device 300.

[0188] [3-4. The effect of linear arraying]

[0189] Refer to this side Figures 20-22 The effect of arranging multiple groups of loudspeaker units in a linear array configuration on the side (hereinafter referred to as "linear arraying") is explained. Figures 20-22 This diagram illustrates the effect of linearly arraying multiple groups of loudspeaker devices.

[0190] like Figure 20 As shown in (a), the following experiment was conducted using one group of loudspeaker units (loudspeaker configuration 1×2) to measure the directivity of the sound output from this group of loudspeaker units. The frequency of the sound output from the one group of loudspeaker units was 500Hz. The measurement results of the directivity of the sound were as follows: Figure 20 As shown in (b).

[0191] In addition, such as Figure 21 As shown in (a), the following experiment was conducted using eight loudspeaker units arranged in a linear array (8×2 loudspeakers), and the directivity characteristics of the sound output from these eight loudspeaker units were measured. The frequency of the sound output from the eight loudspeaker units was 500 Hz. The measurement results of the sound directivity characteristics were as follows: Figure 21 As shown in (b).

[0192] In addition, such as Figure 22 As shown in (a), the following experiment was conducted using 16 groups of loudspeaker units arranged in a linear array (loudspeaker configuration 16×2), and the directivity characteristics of the sound output from these 16 groups of loudspeaker units were measured. The frequency of the sound output from the 16 groups of loudspeaker units was 500Hz. The measurement results of the directivity characteristics of the sound were as follows: Figure 22 As shown in (b).

[0193] in addition, Figure 20 (b) Figure 21 (b) and Figure 22 The two solid lines in (b) are used to illustrate the sharpness of the sound's directivity. The closer the two solid lines are to being parallel to each other, the greater the sharpness of the sound's directivity (that is, the narrower the directivity).

[0194] pass Figure 20 (b) Figure 21 (b) and Figure 22 (b) It is clear that, compared to a single loudspeaker device without linear array, a multi-group linear array has a narrower range of sound pressure levels and a sharper directional characteristic of sound.

[0195] In addition, through Figure 21 (b) and Figure 22 (b) It can be clearly known that as the number of linear array loudspeaker devices increases, the range of sound pressure levels becomes narrower and the sharpness of the sound's directivity characteristics increases.

[0196] (Implementation Method 4)

[0197] [4-1. Structure of a loudspeaker assembly]

[0198] refer to Figures 23-25 The structure of the loudspeaker device 400 according to Embodiment 4 will be explained. Figure 23 This is a block diagram showing the structure of the loudspeaker device 400 in Embodiment 4. Figure 24 as well as Figure 25 This is a diagram illustrating the directional characteristics of the sound output from the loudspeaker device 400 in Embodiment 4.

[0199] like Figure 23 As shown, the loudspeaker device 400 according to Embodiment 4 includes a loudspeaker 1, a loudspeaker 2, an angle sensor 56, and a control unit 58.

[0200] Speaker 1 and speaker 2 are configured in the same way as those described in Embodiment 1. Speaker 1 and speaker 2 are configured such that the direction of sound output by speaker 1 is X1 (refer to...). Figure 1B The direction of sound output from speaker 2, X2 (reference) Figure 1B The angle θ formed by (reference) Figure 1B The configuration is variable. That is, speaker 1 and speaker 2 are configured to be able to rotate relative to each other.

[0201] Angle sensor 56 is a sensor used to detect the aforementioned angle θ. Angle sensor 56 outputs the detected angle θ to control unit 58.

[0202] The control unit 58, according to the angle θ detected by the angle sensor 56, adjusts the input to the input terminal 7 (reference). Figure 3A The gain of the input sound signal, that is, the gain of the input sound signal or inverted sound signal input to speaker 1 and the gain of the input sound signal or inverted sound signal input to speaker 2, is adjusted for each frequency band. The control unit 58, for example, determines the gain corresponding to the angle θ detected by the angle sensor 56 for each frequency band by referring to a correspondence table stored in the storage unit (not shown) that shows the correspondence between the angle θ and the gain for each frequency band.

[0203] Here as Figure 24 as well as Figure 25 As shown, the directivity of the sound output from the loudspeaker device 400 varies with angle θ at each frequency.

[0204] For example Figure 24 As shown, when the frequency of the sound output from the loudspeaker device 400 is 500Hz, the directivity characteristics at angles θ of 50° and 80° are lower than those at angles θ of 40°, 60°, 70° and 90°, resulting in an overall decrease in sound pressure.

[0205] In addition, for example Figure 25 As shown, when the frequency of the sound output from the loudspeaker device 400 is 2kHz, the directivity characteristics at an angle θ of 80° are lower than those at angles θ of 40°, 50°, 60°, 70°, and 90°, resulting in an overall decrease in sound pressure.

[0206] Therefore, when the angle θ detected by the angle sensor 56 is, for example, 50°, the control unit 58 increases the gain of the input audio signal or the reversed audio signal corresponding to a frequency of 500Hz. Furthermore, when the angle θ detected by the angle sensor 56 is, for example, 80°, the control unit 58 increases the gain of the input audio signal or the reversed audio signal corresponding to frequencies of 500Hz and 2kHz.

[0207] Therefore, even if the user rotates speaker 1 and speaker 2 relative to each other to change the angle θ at any angle, deviations in directivity characteristics between multiple frequencies can be suppressed.

[0208] Alternatively, the structure described above can be as follows: when the correspondence between the height of the speaker device 400 from the floor and the angle θ is predetermined, the control unit 58 obtains information related to the height of the speaker device 400 from the floor, and adjusts the gain of the input sound signal or inverted sound signal input to the speaker 1 and the gain of the input sound signal or inverted sound signal input to the speaker 2 according to the obtained information related to the height of the speaker device 400 from the floor.

[0209] [4-2. Effect]

[0210] In this embodiment, the angle θ formed by the direction of sound output from speaker 1 and the direction of sound output from speaker 2 is variable.

[0211] As described above, by adjusting the angle θ, the directional characteristics and the range of directional reach in the target frequency band can be adjusted.

[0212] Furthermore, in this embodiment, the loudspeaker device 400 also includes a control unit 58, which adjusts the gain of the input sound signal or inverted sound signal input to the loudspeaker 1 and the gain of the input sound signal or inverted sound signal input to the loudspeaker 2 according to the angle θ.

[0213] As described above, even if the user rotates speaker 1 and speaker 2 relative to each other to change the angle θ at any angle, deviations in directivity characteristics between multiple frequencies can be suppressed.

[0214] (Other variations, etc.)

[0215] As described above, embodiments 1 to 4 have been illustrated as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these and can also be applied to embodiments with modifications, substitutions, additions, omissions, etc. Furthermore, the various constituent elements described in embodiments 1 to 4 can be combined to create new embodiments.

[0216] Therefore, the following other implementation methods are illustrated.

[0217] In the above embodiments, the orientation of the overall configuration of the speaker device 100 (200, 300, 400) is shown as either upward or downward, but the orientation is arbitrary, for example, it can be oriented to the side or to the tilt.

[0218] Furthermore, in embodiments 2 and 3 described above, the speaker devices 100a, 100b (100a, 100b, 100c, 100d) included in the speaker device 200 (300) are arranged in a straight line in a single column on the side, but are not limited to this arrangement. For example, the speaker devices 100a, 100b (100a, 100b, 100c, 100d) included in the speaker device 200 (300) can be freely arranged on a plane.

[0219] In addition, such as Figure 26 As shown, it can be set up three-dimensionally in the vertical direction. Figure 26 This is a perspective view showing the structure of the loudspeaker device 500 in the modified example. Figure 26 As shown, the modified example of the loudspeaker device 500 includes an upward-facing loudspeaker device 100a and a downward-facing loudspeaker device 100c. The upward-facing loudspeaker device 100a and the downward-facing loudspeaker device 100c are arranged adjacent to each other. This arrangement allows for the creation of a more three-dimensional sound field. Furthermore, in Figure 26 In the illustrated structure, the upper speaker device 100a can be used to output normal sound, and the lower speaker device 100c can be used to output masking sound. Conversely, the upper speaker device 100a can also be used to output masking sound, and the lower speaker device 100c can be used to output normal sound. Alternatively, the two linearly arrayed speaker devices can be arranged vertically adjacent to each other. In this case, the two linearly arrayed speaker devices can be arranged in a cross shape in the plan view, or they can be arranged in an overlapping manner (i.e., parallel to each other). Furthermore, by increasing the number of speaker devices in the vertical direction, the same effect as in Embodiments 2 and 3 can be obtained three-dimensionally.

[0220] In the above embodiments, the loudspeaker device 100 (200, 300, 400) includes a phase switching circuit 6 and is configured to switch between the sounds output from loudspeaker 1 and loudspeaker 2 being in phase or out of phase with each other, but is not limited thereto. The loudspeaker device 100 may also lack the phase switching circuit 6 and output the sound signal input from the input terminal 7 as either in phase or out of phase with each other from loudspeaker 1 and loudspeaker 2. For example, in the structure of embodiment 3 above, in loudspeaker devices 100a and 100b that receive loudspeaker input signals, the input terminal 7 is electrically connected to the input terminals 10 and 11 in a manner that outputs out-of-phase sounds from loudspeaker 1 and loudspeaker 2; in loudspeaker devices 100c and 100d that receive masking signals, the input terminal 7 is electrically connected to the input terminals 10 and 11 in a manner that outputs in-phase sounds from loudspeaker 1 and loudspeaker 2.

[0221] In the above embodiment 3, a structure was described in which an input sound signal (speaker input signal) and a masking signal are input to the speaker device 300 from the input terminal. However, the method of inputting sound signals from external sources is not limited to this. For example, the speaker device 300 can be input with an input sound signal and a masking signal from a communication device. Specifically, the communication device can also input the input sound signal and masking signal to the speaker device 300 by communicating wirelessly or wiredly with an external sound reproduction device that has communication capabilities. The communication device has a CPU (Central Processing Unit), a memory, and a communication interface. The communication interface of the communication device receives the input sound signal from the sound reproduction device and outputs the received input sound signal to speaker devices 100a and 100b. Thus, speaker devices 100a and 100b output the sound of a conference based on the input sound signal. Furthermore, speaker devices 100c and 100d output masking sound based on a masking signal pre-stored in the memory of the communication device. At this time, the CPU of the communication device controls the amplification rate in the amplifier according to each sound signal, thereby controlling the sound signals described in Embodiment 3 in the speaker device 300. Furthermore, regarding the masking signal, the speaker device 300 can be equipped with a storage medium such as a memory to store the masking signal, read it from the storage medium, and output the masking sound from the speaker devices 100c and 100d. Similarly, in Embodiments 1, 2, and 4, the input sound signal from the communication device is input to the speaker devices 100, 200, and 400.

[0222] In the various embodiments described above, loudspeaker 1 and loudspeaker 2 are arranged in a linearly symmetrical manner with respect to reference plane 3, with the direction of sound output intersecting each other, and the other loudspeaker positioned in the direction of sound output from one loudspeaker. However, this is not a limitation. The arrangement of loudspeaker 1 and loudspeaker 2 can be such that the direction of sound output intersectes each other, with the other loudspeaker positioned on the side opposite to the direction of sound output from one loudspeaker. That is, loudspeaker 1 and loudspeaker 2 can be configured to be arranged back-to-back with an angle to each other. Here, "the other loudspeaker positioned on the side opposite to the direction of sound output from one loudspeaker" more specifically means, for example, when loudspeaker 1 is viewed from a direction perpendicular to direction X1, loudspeaker 2 is positioned further back than loudspeaker 1 (in the direction opposite to the direction of sound output) in a direction parallel to direction X1. In this case, the overall shape of the loudspeaker device 100 (200, 300, 400) becomes such that loudspeaker 1 and 2 are respectively arranged on both sides of the sloping surface of a mountain-shaped frame. However, when the sound field characteristics (directivity characteristics) of the loudspeaker device 100 are viewed from the side, the sound field characteristics of the configuration shown in Embodiments 1 to 4 are sharper, so the configuration shown in Embodiments 1 to 4 is better.

[0223] In the above embodiments, the phase switching circuit 6 is described as a circuit that outputs the phase of the input sound signal input to the speaker 1 either as is or inverted. However, it is not limited to this. Any circuit that can control the phase in the speaker device 100 (200, 300, 400) of this disclosure can be any circuit. For example, the phase switching circuit 6 can be any circuit that can switch the sound signals input to the speaker 1 and the speaker 2 to be in phase or out of phase by controlling the input sound signal.

[0224] The phase switching circuit 6 can be implemented in various forms. For example, it can be constructed using electrical switching switches and relays, or it can use a processor. When a processor is used as a control circuit, the program is read from a storage medium and executed by the processor to perform various processes. Therefore, by modifying the program stored in the storage medium, the processing content can be changed, thus increasing the freedom to change the control content. Examples of processors include CPUs and MPUs (Micro-Processing Units). Examples of storage media include hard disks, flash memory, and optical disks. In addition, wiring logic that cannot be rewritten as a control circuit can also be used. Using wiring logic as a control circuit is effective in improving processing speed. Examples of wiring logic include ASICs (Application Specific Integrated Circuits). Furthermore, the control circuit can be implemented by combining a processor and wiring logic. Implementing the control circuit by combining a processor and wiring logic increases both the freedom of software design and the processing speed. Furthermore, the control circuit and circuits with other functions can be constructed using a single semiconductor element. As a circuit with other functions, it may include, for example, an A / D or D / A conversion circuit. Furthermore, the control circuit can be constructed from a single semiconductor element or from multiple semiconductor elements. When constructed from multiple semiconductor elements, the various controls described in the technical solution can be implemented using different semiconductor elements. Moreover, the control circuit can also be constructed using a structure that includes semiconductor elements and passive components such as resistors or capacitors.

[0225] Furthermore, in the described embodiment, each component can be constructed by dedicated hardware or implemented by executing software programs suitable for each component. Each component can be implemented by a program execution unit such as a CPU or processor reading and executing software programs recorded on a recording medium such as a hard disk or semiconductor memory.

[0226] As described above, embodiments have been illustrated as examples of the technology in this disclosure. Drawings and detailed descriptions are provided for this purpose.

[0227] Therefore, the constituent elements described in the accompanying drawings and detailed description include not only those essential for solving the problem, but also those used to illustrate the above-described technology that are not essential for solving the problem. Therefore, the inclusion of non-essential constituent elements in the accompanying drawings and detailed description does not automatically make those essential constituent elements essential.

[0228] Furthermore, the above embodiments are solutions used to illustrate the technology of this disclosure, so various changes, substitutions, additions, omissions, etc., can be made within the scope of the technical solution or its equivalents.

[0229] This disclosure is applicable to loudspeaker devices capable of controlling the directivity of a sound field. Specifically, it is applicable to loudspeaker devices for conference systems or spatial audio systems.

[0230] Symbol Explanation

[0231] 1, 1a, 1b, 1c, 1d, 2, 2a, 2b, 2c, 2d speakers

[0232] 3 reference planes

[0233] 4, 4a, 4b, 4c, 4d, 5, 5a, 5b, 5c, 5d (frames)

[0234] 6, 6a, 6b Phase switching circuits

[0235] Input terminals 7, 7a, 7b, 10, 10a, 10b, 11, 11a, 11b

[0236] 8, 8a, 8b switch

[0237] Sound field curves 12, 13, 14, and 15

[0238] Participants of meetings 23, 24, 25, and 26

[0239] 27 tables

[0240] 28 outsiders

[0241] 29 canopies

[0242] 30 partitions

[0243] Sound field curves 31, 32, 33, 34, 35, 36, 37, 38, 46, 47, 48, 49, 50, 51, 52, 53, 54

[0244] 39 crossbeams

[0245] 56-angle sensor

[0246] 58 Control Department

[0247] 100, 100a, 100b, 100c, 100d, 200, 300, 400, 500 loudspeaker units

Claims

1. A loudspeaker device comprising: The first speaker outputs sound. The second loudspeaker is configured adjacent to the first loudspeaker in a predetermined direction, and outputs sound in a direction intersecting the direction in which the first loudspeaker outputs sound; and The phase control circuit is capable of switching between a first switching state and a second switching state. The first switching state is when both the first and second speakers are input with the same input sound signal. The second switching state is when one of the first and second speakers is input with the same input sound signal, and the other speaker is input with an inverted sound signal, where the inverted sound signal is obtained by reversing the phase of the input sound signal. The first speaker and the second speaker are configured such that the other speaker is positioned in the direction in which the sound is output from one speaker.

2. The loudspeaker device as claimed in claim 1, The angle formed by the direction of the sound output from the first speaker and the direction of the sound output from the second speaker is in the range of 60° to 120°.

3. The loudspeaker device as claimed in claim 1, The loudspeaker device also includes a third loudspeaker, which is configured adjacent to the first loudspeaker and the second loudspeaker in a direction intersecting the predetermined direction, and the third loudspeaker outputs sound based on a sound signal that is different from the input sound signal and the inverted sound signal.

4. The loudspeaker device as claimed in claim 1, The angle formed by the direction of the sound output from the first speaker and the direction of the sound output from the second speaker is variable.

5. The loudspeaker device as claimed in claim 4, The loudspeaker device further includes a control unit that adjusts the gain of the input sound signal or the inverted sound signal input to the first loudspeaker and the gain of the input sound signal or the inverted sound signal input to the second loudspeaker according to the angle.

6. The loudspeaker device as claimed in claim 1, It is provided with multiple groups consisting of the first speaker and the second speaker. The first and second loudspeakers of the plurality of groups are configured in a linear array in a direction intersecting the specified direction.

7. The loudspeaker device as claimed in any one of claims 1 to 6, The speaker device also includes an input terminal for receiving the input sound signal. The phase control circuit can switch the output to either output the input audio signal received from the input terminal as is, or output the inverted audio signal obtained by inverting the phase of the input audio signal. In the first switching state, the input audio signal output from the phase control circuit is input to the first speaker, and the input audio signal from the input terminal is input to the second speaker. In the second switching state, the inverted sound signal output from the phase control circuit is input to the first speaker, and the input sound signal from the input terminal is input to the second speaker.

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