Multichannel audio system

Abstract

This system provides a multi-channel audio experience that allows you to enjoy high-quality multi-channel audio without overwhelming the room with speakers. [Solution] The system comprises an audio device 1 that reproduces and outputs multi-channel audio data as audio signals for multiple channels, and multiple speakers 2-1 to 2-7, each corresponding to one of these multiple channels. The multiple speakers 2-1 to 2-7 are installed on the ceiling and each emits the audio signal for its corresponding channel, which is output from the audio device 1. Here, the speakers 2-1 to 2-7 corresponding to channels other than the height channels are configured such that the audio signal emitted from them reflects off the wall and reaches the listening point P from a direction determined relative to their corresponding channel.

Description

Technical Field

[0001] The present invention relates to a multi-channel audio system.

Background Art

[0002] Conventionally, a multi-channel audio system that reproduces multi-channel audio data into audio signals of a plurality of channels and outputs the reproduced audio signals from speakers corresponding to the channels of the audio signals is known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, in a multi-channel audio system, for example, the speaker corresponding to the center channel is in front of the listening point, the speaker corresponding to the front left channel is in the front left of the listening point, and the speaker corresponding to the front right channel is in the front right of the listening point. For each channel, the speaker corresponding to this channel needs to be installed at a position corresponding to this channel. For this reason, the speakers occupy a considerable space on the floor of the room where the multi-channel audio system is installed, which may interfere with the indoor living flow line or give a sense of oppression to the room. On the other hand, it is conceivable to install all the speakers on the ceiling. However, in this case, it may not be possible to deliver the audio signal emitted from the speaker to the listening point from a direction suitable for the corresponding channel of this speaker, and it may not be possible to reproduce an optimal sound field at the listening point.

[0005] This invention has been made in view of the above circumstances, and its purpose is to provide a multi-channel audio system that can reproduce a higher quality acoustic space at the listening point while maintaining a comfortable indoor environment. [Means for solving the problem]

[0006] To solve the above problems, a multi-channel audio system according to a first aspect of the present invention comprises an audio device that reproduces and outputs multi-channel audio data as audio signals for multiple channels, and a plurality of speakers provided corresponding to each of these multiple channels.

[0007] Here, multiple speakers are mounted on the ceiling, each emitting an audio signal for its corresponding channel, output from the audio equipment.

[0008] Furthermore, for speakers other than the height channels among the multiple speakers, the direction of sound emission is set so that the audio signal emitted from the speaker reflects off the wall and reaches the listening point from a predetermined direction relative to its corresponding channel.

[0009] For example, the sound emission direction of the speaker corresponding to the center channel is set so that the emitted audio signal reflects off the wall directly in front of the user at the listening point and reaches the listening point from directly in front of the user; the sound emission direction of the speaker corresponding to the front left channel is set so that the emitted audio signal reflects off the wall directly to the left of the user at the listening point and reaches the listening point from the front left of the user; and the sound emission direction of the speaker corresponding to the front right channel is set so that the emitted audio signal reflects off the wall directly to the right of the user at the listening point and reaches the listening point from the front right of the user.

[0010] For example, a first aspect of the present invention is: A multichannel audio system comprising an audio device that reproduces and outputs multichannel audio data as multiple channel audio signals, and a plurality of speakers provided corresponding to each of the multiple channels, The aforementioned multiple speakers are installed on the ceiling of the room and each emits an audio signal of its corresponding channel, which is output from the audio device. Of the multiple speakers mentioned above, the sound emission direction of the speakers corresponding to channels other than the height channel is set such that the audio signal emitted from the speaker reflects off the walls of the room and reaches the listening point set in the room from a direction determined for the channel corresponding to that speaker.

[0011] Furthermore, a multi-channel audio system according to a second aspect of the present invention comprises an audio device that reproduces and outputs multi-channel audio data as audio signals for multiple channels, a plurality of speakers provided corresponding to each of these multiple channels, and a plurality of reflectors provided corresponding to the speakers corresponding to channels other than the height channel.

[0012] Here, multiple speakers are mounted on the ceiling, each emitting the audio signal for its corresponding channel, output from the audio equipment, downwards.

[0013] Furthermore, each of the multiple reflectors is positioned below the speaker corresponding to it within the room, and reflects the audio signal emitted from this speaker so that it reaches the listening point set in the room from a direction determined for the channel corresponding to this speaker.

[0014] For example, the first reflector is positioned below the speaker corresponding to the center channel and reflects the audio signal emitted from this speaker so that it reaches the listening point from directly in front of the user at the listening point; the second reflector is positioned below the speaker corresponding to the front left channel and reflects the audio signal emitted from this speaker so that it reaches the listening point from the user's left front; and the third reflector is positioned below the speaker corresponding to the front right channel and reflects the audio signal emitted from this speaker so that it reaches the listening point from the user's right front.

[0015] For example, a second aspect of the present invention is: A multi-channel audio system comprising an audio device that reproduces and outputs multi-channel audio data as multiple-channel audio signals, and multiple speakers provided corresponding to each of the multiple channels, The aforementioned plurality of speakers have a plurality of reflectors provided for the speakers corresponding to channels other than the height channel, The aforementioned multiple speakers are installed on the ceiling of the room, and each emits the audio signal of the channel corresponding to that speaker, output from the audio device, downwards. Each of the plurality of reflectors is positioned below the speaker corresponding to the speaker in the room, and reflects the audio signal emitted from the speaker so that it reaches the listening point set in the room from a direction determined for the channel corresponding to the speaker. [Effects of the Invention]

[0016] In the present invention, an audio signal emitted from a speaker corresponding to a channel other than the high channel is reflected by a reflector installed below a wall surface or the speaker as the sound source, and reaches a listening point from a defined direction with respect to the channel corresponding to the speaker as the sound source. Therefore, even when a plurality of speakers are installed on the ceiling, an acoustic space similar to that in the case of installation on the floor surface according to the standard layout can be reproduced at the listening point. Further, since there is no need to install the speakers on the floor surface of the room, or since it is sufficient to arrange a reflector that is thinner than the speakers and is easy to move on the floor surface of the room, the interior can be made to look spacious and neat, and elements that hinder movement in the room can be reduced.

[0017] Therefore, according to the present invention, while maintaining a comfortable indoor environment, a higher-quality acoustic space can be reproduced at the listening point.

Brief Description of the Drawings

[0018] [Figure 1] FIG. 1 is a schematic configuration diagram of a multi-channel audio system constructed indoors according to the first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram for explaining the positional relationship between the speaker 2 arranged on the ceiling and the user. [Figure 3] FIG. 3 is a diagram for explaining the sound emission directions of the speaker 2-2 corresponding to the front left channel and the speaker 2-3 corresponding to the front right channel. [Figure 4] FIG. 4 is a diagram for explaining the sound emission directions of the speaker 2-1 corresponding to the center channel, the speaker 2-4 corresponding to the surround left channel, the speaker 2-5 corresponding to the surround right channel, the speaker 2-6 corresponding to the height left channel, and the speaker 2-7 corresponding to the height right channel. [Figure 5] FIG. 5 is a schematic functional configuration diagram of the audio device 1. [Figure 6] FIG. 6 is a flowchart for explaining the acoustic profile information setting process of the audio device 1. [Figure 7] FIG. 7 is a flowchart for explaining the acoustic profile information change process of the audio device 1. [Figure 8] FIG. 8 is a schematic cross-sectional view for explaining the internal structure of the speaker 2. [Figure 9] FIG. 9 is a schematic functional configuration diagram of the wireless terminal 3. [Figure 10] FIG. 10 is a flowchart for explaining the acoustic profile information setting support process of the wireless terminal 3. [Figure 11] FIG. 11 is a flowchart for explaining the output characteristic adjustment process of the wireless terminal 3. [Figure 12] FIG. 12 is a flowchart for explaining the motor control process of the wireless terminal 3. [Figure 13] FIGS. 13(A) and (B) are a top view and a side view of a modified example 2A of the speaker 2. [Figure 14] FIG. 14 is a schematic configuration diagram of a multi-channel audio system according to the second embodiment of the present invention. [Figure 15] FIG. 15 is a diagram for explaining the traveling directions of audio signals emitted from each of the speaker 2B-2 corresponding to the front left channel and the speaker 2B-3 corresponding to the front right channel. [Figure 16] FIG. 16 is a diagram for explaining the traveling directions of audio signals emitted from each of the speaker 2B-1 corresponding to the center channel, the speaker 2B-4 corresponding to the surround left channel, the speaker 2B-5 corresponding to the surround right channel, the speaker 2B-6 corresponding to the height left channel, and the speaker 2B-7 corresponding to the height right channel. [Figure 17] FIGS. 17(A) and 17(B) are a schematic front view and a schematic side view of the reflector 4. Embodiments for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0020] In the following, assuming that the user is facing one direction while listening to multi-channel audio at a listening point set up in the room, for example, the side wall in front of the user will be called the front wall, and the side walls behind, to the right, and to the left of the user will be called the back wall, right wall, and left wall, respectively. Furthermore, the room area between the front wall and the back wall will be divided into three regions aligned from the front wall to the back wall, with the region along the front wall being called the front region R1, the region along the back wall being called the rear region R3, and the region located between the front region R1 and the rear region R3, including the listening point, being called the intermediate region R2.

[0021] [First Embodiment] First, a first embodiment of the present invention will be described.

[0022] Figure 1 is a schematic diagram of a multi-channel audio system constructed indoors according to this embodiment.

[0023] As shown in the figure, the multi-channel audio system according to this embodiment comprises an audio device 1, a plurality of speakers 2-1 to 2-7 (hereinafter also simply referred to as speaker 2) installed on the ceiling, and a wireless terminal 3.

[0024] Audio device 1 downloads multi-channel audio data from a media server (not shown) or the like via a network, and reproduces this multi-channel audio data as audio signals for the center channel (hereinafter referred to as C channel), front left channel (hereinafter referred to as FL channel), front right channel (hereinafter referred to as FR channel), surround left channel (hereinafter referred to as SL channel), surround right channel (hereinafter referred to as SR channel), high left channel (hereinafter referred to as HL channel), and height right channel (hereinafter referred to as HR channel). It then wirelessly transmits the audio signals of each reproduced channel to speaker 2.

[0025] Speaker 2 is provided in correspondence to each of the multiple channels wirelessly transmitted from audio device 1, and receives the audio signal for its corresponding channel and emits sound. Preferably, speaker 2 is a directional speaker such as a parametric speaker with a narrow sound beam emission range.

[0026] Here, speaker 2-1 is provided for the C channel, speaker 2-2 for the FL channel, speaker 2-3 for the FR channel, speaker 2-4 for the SL channel, speaker 2-5 for the SR channel, speaker 2-6 for the HL channel, and speaker 2-7 for the HR channel.

[0027] Figure 2 is a diagram illustrating the positional relationship between speaker 2, which is positioned on the ceiling, and the user at listening point P.

[0028] As shown in the diagram, when listening point P is projected directly upwards towards the ceiling, speakers 2-1 to 2-7 are positioned on the ceiling so as to surround the projection point of listening point P.

[0029] Speakers 2-1 (C channel), 2-2 (FL channel), and 2-3 (FR channel) are located in the front region R1. Speaker 2-1 is positioned between the projection point of listening point P and the front wall, while speakers 2-2 and 2-3 are positioned between the line passing through speaker 2-1 and the projection point of listening point P (hereinafter referred to as the ceiling centerline) and the left wall, and between the ceiling centerline and the right wall, respectively. Speakers 2-6 (HL channel) and 2-7 (HR channel) are located in the middle region R2, between the ceiling centerline and the left wall, and between the ceiling centerline and the right wall, respectively. Speakers 2-4 (SL channel) and 2-5 (SR channel) are located in the rear region R3, between the ceiling centerline and the left wall, and between the ceiling centerline and the right wall, respectively.

[0030] With speaker 2 positioned on the ceiling in this layout, for the user at listening point P, speaker 2-1 for the C channel is positioned directly in front and above, speaker 2-2 for the FL channel is positioned to the left front, speaker 2-3 for the FR channel is positioned to the right front, speaker 2-4 for the SL channel is positioned to the left rear, speaker 2-5 for the SR channel is positioned to the right rear, speaker 2-6 for the HL channel is positioned to the left upper, and speaker 2-7 for the HR channel is positioned to the upper right.

[0031] Figure 3 is a diagram illustrating the sound emission direction of speaker 2-2, which is compatible with the FL channel, and speaker 2-3, which is compatible with the FR channel.

[0032] As shown in the diagram, the sound emission direction of speaker 2-2, which corresponds to the FL channel, is set so that the audio beam 40-2 of the FL channel audio signal emitted from speaker 2-2 reflects off the left wall and reaches the user at listening point P from the left front (the direction defined as the direction of sound arrival relative to the FL channel). The sound emission direction of speaker 2-3, which corresponds to the FR channel, is set so that the audio beam 40-3 of the FR channel audio signal emitted from speaker 2-3 reflects off the right wall and reaches the listening point P from the right front of the user (the direction defined as the direction of sound arrival relative to the FR channel).

[0033] Figure 4 is a diagram illustrating the sound emission direction of speaker 2-1 (C channel), speaker 2-4 (SL channel), speaker 2-5 (SR channel), speaker 2-6 (HL channel), and speaker 2-7 (HR channel).

[0034] As shown in the diagram, the sound emission direction of speaker 2-1, which corresponds to the C channel, is set so that the audio beam 40-1 of the C channel audio signal emitted from speaker 2-1 is reflected off the front wall and reaches the listening point P from the front of the user (the direction defined as the direction of sound arrival for the C channel). Similarly, the sound emission directions of speaker 2-4, which corresponds to the SL channel, and speaker 2-5, which corresponds to the SR channel, are set so that the audio beams 40-4 and 40-5 of the SL channel and SR channel audio signals emitted from these speakers 2-4 and 2-5 are reflected off the back wall and reach the listening point P from the left rear and right rear of the user (the directions defined as the direction of sound arrival for the SL channel and SR channel). The sound emission directions of speakers 2-6 (HL channel compatible) and 2-7 (HR channel compatible) are set so that the audio beams 40-6 and 40-7 of the HL and HR channel audio signals emitted from these speakers 2-6 and 2-7 are directed directly toward the user at listening point P.

[0035] Wireless terminal 3 is, for example, a smartphone or a tablet PC (Personal Computer), and functions as a remote controller for audio device 1 and speaker 2.

[0036] Next, the audio device 1, speaker 2, and wireless terminal 3 that constitute the multi-channel audio system according to this embodiment will be described in detail.

[0037] First, let me explain the details of audio device 1.

[0038] Figure 5 is a schematic diagram of the functional configuration of audio device 1.

[0039] As shown in the figure, the audio device 1 includes a wireless network interface unit 100, a music acquisition unit 101, a content storage unit 102, a test signal sound source storage unit 103, an acoustic profile information storage unit 104, an audio playback unit 105, an output characteristic adjustment unit 106, an instruction receiving unit 107, a sound collection signal receiving unit 108, a measurement unit 109, an acoustic profile information generation unit 110, and a main control unit 111.

[0040] The wireless network interface unit 100 is an interface for wireless communication with the speaker 2, the wireless terminal 3, and a media server (not shown).

[0041] The music acquisition unit 101 accesses a media server (not shown) via the wireless network interface unit 100 and downloads multi-channel audio data of the music from this media server.

[0042] The content storage unit 102 stores multi-channel audio data of music downloaded from a media server (not shown).

[0043] The test signal sound source storage unit 103 stores the test signal sound source.

[0044] The acoustic profile information storage unit 104 stores acoustic profile information generated by the acoustic profile information generation unit 110 for each channel of the multi-channel audio data. In this embodiment, acoustic profile information for the C channel, FL channel, FR channel, SL channel, SR channel, HL channel, and HR channel is stored.

[0045] The audio playback unit 105 plays back and outputs audio signals for the C channel, FL channel, FR channel, SL channel, SR channel, HL channel, and HR channel from the multi-channel audio data stored in the content storage unit 102. It also plays back test signal sound sources stored in the test signal sound source storage unit 103 and outputs the played-back test signals as test signals for the channels specified by the main control unit 111.

[0046] The output characteristic adjustment unit 106 adjusts the output timing and volume level of each audio signal output from the audio playback unit 105 according to the acoustic profile information for that audio signal channel stored in the acoustic profile information storage unit 104. Then, the audio signals for each channel with adjusted output timing and volume level are wirelessly transmitted from the wireless network interface unit 100.

[0047] The instruction receiving unit 107 receives various instructions from the wireless terminal 3 via the wireless network interface unit 100.

[0048] The sound collection signal receiving unit 108 receives a signal (amplified test signal) obtained by collecting a test signal emitted by speaker 2 at listening point P from wireless terminal 3 via wireless network interface unit 100.

[0049] The measurement unit 109 compares the test signal output by the audio playback unit 105 with the collected signal received by the collected signal receiving unit 108 for each channel, and measures the delay time and attenuation rate of the collected signal relative to the test signal.

[0050] The acoustic profile information generation unit 110 generates acoustic profile information for each channel, including output timing and volume level, based on the measurement results from the measurement unit 109 (delay time and attenuation rate of the collected signal relative to the test signal).

[0051] The main control unit 111 then comprehensively controls each of the audio device 1 parts 100 to 110.

[0052] The functional configuration of the audio device 1 shown in Figure 5 can be implemented in hardware using integrated logic ICs such as ASICs (Application Specific Integrated Circuits) and FPGAs (Field Programmable Gate Arrays), or in software using a computer such as a DSP (Digital Signal Processor). Alternatively, it can be implemented as a process in a general-purpose computer such as a PC, which is equipped with a CPU, memory, auxiliary storage devices such as flash memory and hard disk drives, and wireless communication devices such as wireless LAN adapters, by having the CPU load a predetermined program from the auxiliary storage device into memory and execute it.

[0053] Figure 6 is a flowchart illustrating the process of setting acoustic profile information for audio device 1.

[0054] This flow is initiated when the instruction receiving unit 107 receives an instruction to set acoustic profile information from the wireless terminal 3 via the wireless network interface unit 100.

[0055] First, the instruction receiving unit 107 passes the acoustic profile information setting instruction received from the wireless terminal 3 to the main control unit 111. In response, the main control unit 111 selects an unselected channel from among the channels that the audio playback unit 105 can play (C channel, FL channel, FR channel, SL channel, SR channel, HL channel, and HR channel) (S100).

[0056] Then, the main control unit 111 reads the test signal sound source from the test signal sound source storage unit 103 and passes this test signal sound source, along with the selection channel, to the audio playback unit 105. In response, the audio playback unit 105 plays the test signal sound source received from the main control unit 111 (S101), and passes the played signal to the main control unit 111 as the test signal for the selected channel, and also transmits it wirelessly from the wireless network interface unit 100 (S102). As a result, the speaker 2 corresponding to the selected channel receives the test signal for the selected channel wirelessly transmitted from the audio device 1 and emits sound. The wireless terminal 3, positioned at the listening point P, collects the test signal emitted from the speaker 2 corresponding to the selected channel and wirelessly transmits the collected signal to the audio device 1.

[0057] Next, when the sound collection signal receiving unit 108 receives a test signal from the wireless terminal 3 via the wireless network interface unit 100 (YES in S103), it passes this sound collection signal to the main control unit 111. The main control unit 111 then passes the sound collection signal received from the sound collection signal receiving unit 108, along with the test signal of the selected channel received from the audio playback unit 105, to the measurement unit 109. In response, the measurement unit 109 compares the test signal and the sound collection signal of the selected channel to measure the delay time and attenuation rate of the sound collection signal relative to the test signal of the selected channel (S104).

[0058] Next, the acoustic profile information generation unit 110 generates acoustic profile information for the selected channel, including playback timing and volume level, based on the measurement results from the measurement unit 109 (delay time and attenuation rate of the collected signal relative to the test signal of the selected channel) (S105). For example, the playback timing of the selected channel is determined so that playback starts by the delay time earlier than the default playback timing, and the volume level of the selected channel is determined so that the volume level after attenuation becomes the default volume level.

[0059] Next, the main control unit 111 stores the acoustic profile information of the selected channel, which is generated by the acoustic profile information generation unit 110, in the acoustic profile information storage unit 104, thereby setting this acoustic profile information as the output condition for the audio signal of the selected channel (S105).

[0060] Then, the main control unit 111 returns to S100 if there are any unselected channels among the channels that the audio playback unit 105 can play (NO in S106), and terminates this flow if all channels have been selected (YES in S106).

[0061] Figure 7 is a flowchart illustrating the process of changing the acoustic profile information of audio device 1.

[0062] This process is performed while the audio playback unit 105 is playing back multi-channel audio data.

[0063] During playback of multi-channel audio data, the audio signals of each channel played back by the audio playback unit 105 are adjusted in terms of output characteristics (output timing and volume level) by the output characteristics adjustment unit 106, then wirelessly transmitted from the wireless network interface unit 100, received by the corresponding speaker 2, and emitted. The wireless terminal 3, positioned at the listening point P, then performs the output characteristics adjustment process described later to monitor the changes in the acoustic characteristics of the audio signals that are reflected off the side walls of the room and reach the user at the listening point P, for each channel. If necessary, it wirelessly transmits an acoustic profile update instruction to the audio device 1, including the designation of the channel to be updated and the amount of adjustment for the output characteristics of the audio signal of the channel to be updated.

[0064] When the instruction receiving unit 107 receives an acoustic profile update instruction from the wireless terminal 3 via the wireless network interface unit 100 (YES in S110), it notifies the main control unit 111 of this acoustic profile update instruction. In response, the main control unit 111 updates the acoustic profile information of the channel to be updated specified in the acoustic profile update instruction, which is stored in the acoustic profile information storage unit 104, according to the adjustment amount included in the acoustic profile update instruction (S111).

[0065] Next, I will explain the details of speaker 2.

[0066] Figure 8 is a schematic cross-sectional view illustrating the internal structure of speaker 2.

[0067] As shown in the figure, speaker 2 comprises a speaker body 20, a movable plate 21 to which the speaker body 20 is attached, a motor 22, a belt 25, a guide member 23, a control unit 24, and a cabinet 26 that houses these members 20 to 25.

[0068] The speaker body 20 is, for example, a speaker cone, which is driven by the control unit 24 to emit sound. The speaker body 20 is attached to the movable plate 21 with its sound-emitting surface facing the opening 260 of the cabinet 26.

[0069] A cylindrical rotating shaft 210 is provided at one end of the movable plate 21, and this rotating shaft 210 is rotatably supported by a support provided on the cabinet 26. A guide pin 211 is attached to the other end of the movable plate 21, and this guide pin is inserted into a guide hole provided on the guide member 23 so that the movable plate 21 rotates around the rotating shaft 210.

[0070] The rotation angle of the output shaft of the motor 22 is controlled by the control unit 24.

[0071] The belt 25 is stretched between the output shaft of the motor 22 and the pulley at the tip of the rotating shaft 210 of the movable plate 21, transmitting the torque of the output shaft of the motor 22 to the rotating shaft 210 of the movable plate 21. As a result, the rotating shaft 210 of the movable plate 21 rotates in conjunction with the output shaft of the motor 22, causing the movable plate 21 to rotate around the rotating shaft 210.

[0072] The guide member 23 has an arc-shaped slit 230 formed around the rotation axis 210 of the movable plate 21, and the guide pin 211 of the movable plate 21 is movably inserted into the slit 230. When the movable plate 21 rotates around the rotation axis 210 at one end due to the output of the motor 22, the guide pin 211 at the other end of the movable plate 21 is guided and moved by the slit 230. This allows for precise control of the tilt angle (tilt angle of the sound-emitting surface) of the speaker body 20 attached to the movable plate 21 with respect to the opening 260 of the cabinet 26, and thus the sound emission direction of the speaker body 20 can be adjusted according to the positional relationship between the adjustment speaker 2 and the listening point P.

[0073] The control unit 24 includes a wireless network interface unit 240, a speaker drive unit 241, and a motor drive unit 242.

[0074] The wireless network interface unit 240 is an interface for wireless communication with the audio device 1 and the wireless terminal 3, and receives the audio signal of the corresponding channel of the speaker 2 transmitted wirelessly from the audio device 1. It also receives a motor control signal from the wireless terminal 3 to rotate the speaker body 20 to a user-specified tilt angle.

[0075] The speaker drive unit 241 drives the speaker body 20 according to the audio signal received by the wireless network interface unit 240, and emits the audio signal from the speaker body 20.

[0076] When the motor control signal (a motor control signal for rotating the speaker body 20 to a user-specified tilt angle) transmitted wirelessly from the wireless terminal 3 is received by the wireless network interface unit 240, the motor drive unit 242 drives the motor 22 according to this motor control signal. As a result, the motor 22 rotates so that the speaker body 20 rotates to a user-specified tilt angle.

[0077] The cabinet 26 is mounted in a mounting hole provided in the ceiling with its opening 260 facing downwards, and is fixed to the ceiling with bolts 261 or the like.

[0078] The control unit 24 of speaker 2 shown in Figure 8 can be implemented in hardware using integrated logic ICs such as ASICs and FPGAs, or in software using a computer such as a DSP.

[0079] Here, for the HL channel compatible speaker 2-6 and the HR channel compatible speaker 2-7, it is sufficient that they can emit sound downwards from the speaker body 20, and the sound emission angle does not need to be adjustable. In this case, the mechanism for rotating the movable plate 21 to which the speaker body 20 is attached (rotating shaft 210, guide pin 211, motor 22, guide member 23, belt 25, and motor drive unit 242) is unnecessary.

[0080] Next, we will explain the details of wireless terminal 3.

[0081] Figure 9 is a schematic diagram of the functional configuration of the wireless terminal 3.

[0082] As shown in the figure, the wireless terminal 3 includes a wireless network interface unit 300, a human-machine interface unit 301, an audio signal acquisition unit 302, a sound collection microphone 303, a channel extraction unit 304, a difference monitoring unit 305, an adjustment amount determination unit 306, a sound collection signal transmission unit 307, an instruction transmission unit 308, and a main control unit 309.

[0083] The wireless network interface unit 300 is an interface for wireless communication with the audio device 1 and the speaker 2.

[0084] The human-machine interface unit 301 is an interface for displaying information to the user and receiving various operations from the user, and has input / output devices such as a touch panel.

[0085] The audio signal acquisition unit 302 acquires the audio signals of each of the multiple channels wirelessly transmitted from the audio device 1.

[0086] The sound-collecting microphone 303 collects the audio signal or test signal emitted from the speaker 2 of each channel and outputs the resulting collected signal (collected audio signal or test signal).

[0087] The channel extraction unit 304 extracts the signal components of the audio signal for each channel from the audio signal collected by the sound-collecting microphone 303, based on the audio signals of each of the multiple channels acquired by the audio signal acquisition unit 302. For example, for each channel, the signal components of the audio signal of the relevant channel are extracted by subtracting the audio signals of all other channels acquired by the audio signal acquisition unit 302 from the audio signal collected by the sound-collecting microphone 303.

[0088] The difference monitoring unit 305 periodically (for example, every 15 minutes) compares the signal components of the audio signal acquired by the audio signal acquisition unit 302 and the audio signal extracted by the channel extraction unit 304 for each channel, thereby monitoring changes in the acoustic characteristics of the audio signal that is reflected from the side walls of the room and reaches the user at listening point P. For example, it monitors fluctuations in the difference in volume levels between the two. If it detects a channel that has experienced a difference fluctuation of a predetermined magnitude or larger as a channel to be updated, it notifies the adjustment amount determination unit 306 of that channel along with the amount of the difference fluctuation.

[0089] The adjustment amount determination unit 306 determines the adjustment amount for the audio signal output characteristics based on the differential fluctuation amount notified along with the channel to be updated, for the channel notified by the differential monitoring unit 305. In this embodiment, the amount by which the volume level of the audio signal is increased or decreased in a direction that cancels out the differential fluctuation (volume level adjustment amount) is determined as the adjustment amount for the audio signal output characteristics.

[0090] The sound collection signal transmission unit 307 transmits the sound collection signal obtained by the sound collection microphone 303 to the audio device 1 via the wireless network interface unit 300.

[0091] The instruction transmission unit 308 transmits various instructions to the audio device 1 via the wireless network interface unit 300, such as instructions for setting acoustic profile information, updating acoustic profile, downloading multi-channel audio data, and playback. The instruction transmission unit 308 also transmits a motor control signal, along with channel specification, to the speaker 2 via the wireless network interface unit 300.

[0092] The main control unit 309 then comprehensively controls each of the wireless terminal 300-308.

[0093] The functional configuration of the wireless terminal 3 shown in Figure 9 is realized as a process in a portable computer such as a smartphone or tablet PC, which is equipped with a CPU, memory, auxiliary storage device such as flash memory, wireless communication device such as a wireless LAN adapter, and microphone, by the CPU executing a predetermined program.

[0094] Figure 10 is a flowchart illustrating the process for assisting in setting acoustic profile information for the wireless terminal 3. Note that this acoustic profile information setting assistance process assumes that the wireless terminal 3 is located at listening point P.

[0095] This process begins when the main control unit 309 receives instructions from the user to set acoustic profile information via the human-machine interface unit 301.

[0096] The main control unit 309 notifies the instruction transmission unit 308 of the instruction to set the acoustic profile information. In response, the instruction transmission unit 308 transmits the instruction to set the acoustic profile information to the audio device 1 via the wireless network interface unit 300 (S200).

[0097] Subsequently, the sound-collecting microphone 303 collects the test signal emitted from the speaker 2 of one of the channels (S201). Then, the main control unit 309 passes the collected test signal obtained by the sound-collecting microphone 303 to the sound-collecting signal transmission unit 307. In response, the sound-collecting signal transmission unit 307 transmits the collected test signal to the audio device 1 via the wireless network interface unit 300 (S202).

[0098] Next, the main control unit 309 returns to S201 if it has not yet transmitted the sound collection signals for all the channels that the audio device 1 can play (NO in S203), and terminates this flow if it has already transmitted all of them (YES in S203).

[0099] Figure 11 is a flowchart illustrating the output characteristic adjustment process for the wireless terminal 3.

[0100] Note that this output characteristic adjustment process assumes that the wireless terminal 3 is located at the listening point P.

[0101] This flow is performed after the instruction transmission unit 308 sends a multi-channel audio data playback instruction to the audio device 1 via the wireless network interface unit 300, that is, while the audio device 1 is playing the multi-channel audio data.

[0102] First, the main control unit 309 instructs the audio signal acquisition unit 302 to acquire audio signals and the sound-collecting microphone 303 to collect audio signals. In response, the audio signal acquisition unit 302 starts acquiring audio signals for each of the multiple channels wirelessly transmitted from the audio device 1 (S210), and the sound-collecting microphone 303 starts collecting audio signals emitted from each of the multiple channels' speakers 2 (S211). Here, the audio signals for each of the multiple channels acquired by the audio signal acquisition unit 302 are input to the channel extraction unit 304 and the difference monitoring unit 305 via the main control unit 309, and the collected signals of the multiple channels' audio signals obtained by the sound-collecting microphone 303 are input to the channel extraction unit 304.

[0103] Next, the channel extraction unit 304 starts extracting the signal components of the audio signals for each channel from the collected audio signals obtained by the sound-collecting microphone 303, based on the audio signals of each of the multiple channels acquired by the audio signal acquisition unit 302 (S212). Specifically, for each channel, the signal components of the audio signal for the relevant channel are extracted by subtracting the audio signals of all other channels from the collected audio signal.

[0104] Next, the difference monitoring unit 305 monitors the difference between the signal components of the audio signal acquired by the audio signal acquisition unit 302 and the audio signal extracted by the channel extraction unit 304 for each channel (S213). Specifically, it monitors the fluctuation of the difference in volume levels between the two. If it detects a channel that has experienced a difference fluctuation of a predetermined magnitude or larger as a channel to be updated (YES in S214), it notifies the adjustment amount determination unit 306 of this channel to be updated along with the amount of the difference fluctuation.

[0105] In response, the adjustment amount determination unit 306 determines the adjustment amount for the audio signal output characteristics based on the differential fluctuation amount notified along with the channel to be updated, as notified by the differential monitoring unit 305 (S215). Specifically, it determines an adjustment amount to increase or decrease the volume level of the audio signal in a direction that cancels out the differential fluctuation. The determined volume level adjustment amount is then notified to the main control unit 309 along with the channel to be updated. The main control unit 309 then notifies the instruction transmission unit 308 of the channel to be updated and the volume level adjustment amount, instructing it to update the acoustic profile.

[0106] In response, the instruction transmission unit 308 creates an acoustic profile update instruction that includes the specification of the channel to be updated and the adjustment amount notified by the main control unit 309, and transmits this acoustic profile update instruction to the audio device 1 via the wireless network interface unit 300 (S216).

[0107] Figure 12 is a flowchart illustrating the motor control process of the wireless terminal 3.

[0108] This process begins when the main control unit 309 receives an instruction from the user via the human-machine interface unit 301 to adjust the tilt angle of speaker 2.

[0109] First, the main control unit 309 receives a specification of the corresponding channel for the speaker 2 to be controlled from the user via the man-machine interface unit 301 (S220), and also receives a specification of the tilt angle of the speaker body 20 (S221). Then, the main control unit 309 notifies the instruction transmission unit 308 of the corresponding channel and tilt angle of the speaker 2 to be controlled received from the user and instructs motor control. In response, the instruction transmission unit 308 transmits a motor control signal from the wireless network interface unit 300 to the user-specified speaker 2 to rotate the speaker body 20 to the user-specified tilt angle (S222).

[0110] The first embodiment of the present invention has been described above.

[0111] In this embodiment, as shown in Figures 3 and 4, audio signals emitted from speakers corresponding to channels other than the height channel (speakers 2-1 to 2-5 corresponding to the C channel, FL channel, FR channel, SL channel, and SR channel) are reflected off the side walls (front wall, left wall, right wall, and rear wall) and reach the user at listening point P from the direction (front, left front, right front, left rear, and right rear) determined for each channel. Therefore, even if these speakers 2-1 to 2-5 are installed on the ceiling, the same acoustic space as when they are installed on the floor in a standard configuration can be reproduced at listening point P. Furthermore, since there is no need to install speakers on the floor, the room can be made to look spacious and uncluttered, and it can be made easier to move around in.

[0112] Therefore, according to this embodiment, a higher quality acoustic space can be reproduced at the listening point while maintaining a comfortable indoor environment.

[0113] Furthermore, in this embodiment, during playback of multi-channel audio data, the wireless terminal 3 acquires the audio signals of each of the multiple channels wirelessly transmitted from the audio device 1 at the listening point P, and also collects the audio signals of each of the multiple channels emitted from the multiple speakers 2. Then, for each channel, it extracts the signal component of the corresponding channel's audio signal from the collected signal obtained by collecting the audio signal, and monitors the difference between the extracted audio signal component and the corresponding channel's audio signal wirelessly transmitted from the audio device 1.

[0114] If there is a channel that has experienced a differential fluctuation of a predetermined magnitude or larger, this channel is selected for updating, and the amount of adjustment to the audio signal output characteristics is determined based on the differential fluctuation amount. An acoustic profile update instruction, along with the determined adjustment amount and the specification of the channel to be updated, is then transmitted to the audio device 1. The audio device 1 then updates the acoustic profile information of the channel to be updated, which is identified by the acoustic profile update instruction received from the wireless terminal 3, according to the adjustment amount specified by this update instruction.

[0115] Therefore, according to this embodiment, even if the reflectivity of the side walls of the room changes due to environmental changes in the room where the multi-channel audio system is installed (changes in temperature, humidity, etc.), or if the degree of attenuation due to air absorption changes for each frequency, the acoustic characteristics of each of the multiple channels of audio signals emitted from the multiple speakers 2 can be stabilized at the listening point P. This makes it possible to enjoy multi-channel audio with even higher quality.

[0116] In this embodiment, the volume level of the acoustic profile information of the channel to be updated is adjusted based on changes in the acoustic characteristics of the audio signal that reflects off the side walls of the room and reaches the user at listening point P. However, the output timing may also be adjusted based on changes in the acoustic characteristics of the audio signal that reflects off the side walls of the room and reaches the user at listening point P. This makes it possible to stabilize the acoustic characteristics at listening point P even when the speed at which the audio signal of each channel propagates is affected by changes in the room environment (changes in temperature, humidity, etc.).

[0117] Furthermore, in this embodiment, the tilt angle of the speaker body 20 is controlled by the motor 22 to adjust the sound emission angle of the speaker 2 so that the audio signal emitted from the speaker 2 reflects off the wall before reaching the listening point P. However, the present invention is not limited to this. Any structure of adjustment mechanism for adjusting the sound emission angle of the speaker 2 may be used.

[0118] For example, the motor 22 and belt 25 may be omitted from speaker 2, and the tilt angle of the speaker body 20 relative to the opening 260 of the cabinet 26 may be changed by manually rotating the movable plate 21 around the rotation axis 210. In this case, a mechanism such as a rotation locking mechanism for the rotation axis 210 of the movable plate 21 can be provided to stop and release the rotation of the rotation axis 210 of the movable plate 21 at a desired tilt angle.

[0119] Alternatively, a single speaker 2 may be equipped with multiple speaker units with different sound emission directions, and the speaker unit to emit the audio signal may be selected from among the multiple speaker units according to instructions from the wireless terminal 3. In this way, the sound emission angle of the audio signal emitted from the speaker can also be adjusted.

[0120] Figures 13(A) and (B) are a top view and a side view of modified speaker 2A.

[0121] As shown in the figure, speaker 2A includes a speaker array 27, a control unit 28, and a cabinet 29.

[0122] The cabinet 29 is cylindrical, and a spherical speaker surface 290 is provided on one end face. The side of the cabinet 29 is also provided with a mounting section 291 having bolt holes for mounting the speaker 2A to the ceiling. The speaker 2A is embedded in the mounting hole in the ceiling with the speaker surface 290 facing downwards, and is fixed to the ceiling by bolts or the like inserted into the bolt holes of the mounting section 291.

[0123] The speaker array 27 consists of multiple speaker bodies 270 arranged in an array on the speaker surface 290 of the cabinet 29. Each of the multiple speaker bodies 270 arranged on the spherical speaker surface 290 has a different sound emission direction.

[0124] The control unit 28 includes a wireless network interface unit 280, a speaker drive unit 281, and a speaker switching unit 282.

[0125] The wireless network interface unit 280 is an interface for wireless communication with the audio device 1 and the wireless terminal 3, and receives the audio signal of the corresponding channel of its own speaker 2A transmitted wirelessly from the audio device 1. It also receives a speaker switching signal from the wireless terminal 3 that specifies one of the speaker units 270.

[0126] The speaker drive unit 281 drives the speaker array 27 according to the audio signal received by the wireless network interface unit 280 and emits the audio signal from the speaker array 27.

[0127] The speaker switching unit 282, in accordance with the speaker switching signal received by the wireless network interface unit 280, turns on the speaker unit 270 specified by the speaker switching signal and turns off the other speaker units 270. This allows the sound emission angle of speaker 2A to be adjusted.

[0128] The control unit 28 of speaker 2A shown in Figure 13(B) is implemented either in hardware using integrated logic ICs such as ASICs and FPGAs, or in software using a computer such as a DSP.

[0129] Furthermore, if a modified version 2A of speaker 2 shown in Figures 13(A) and 13(B) is used instead of speaker 2 shown in Figure 8, the wireless terminal 3, in S221 of Figure 12, receives a designation of the speaker body 270 to be turned on, instead of receiving the tilt angle from the user, and in S222 of the same figure, transmits a speaker switching signal to the controlled speaker 2A in the speaker array 27, along with the designation of the speaker body 270 to be turned on, instead of a motor control signal.

[0130] [Second Embodiment] Next, a second embodiment of the present invention will be described.

[0131] Figure 14 is a schematic diagram of a multi-channel audio system constructed indoors according to this embodiment.

[0132] As shown in the figure, the multi-channel audio system according to this embodiment differs from the multi-channel audio system according to the first embodiment shown in Figure 1 in that multiple speakers 2B-1 to 2B-7 (hereinafter also simply referred to as speaker 2B) are installed on the ceiling instead of multiple speakers 2-1 to 2-7, and multiple reflectors 4-1 to 4-5 (hereinafter also simply referred to as reflector 4) are provided in the room. The other configurations are the same as those of the multi-channel audio system according to the first embodiment.

[0133] Speaker 2B is provided in correspondence to each of the multiple channels wirelessly transmitted from the audio device 1, and receives the audio signal for its corresponding channel and emits sound downwards. It is preferable that speaker 2B is a directional speaker, such as a parametric speaker, with a narrow sound beam emission range, similar to speaker 2 in the first embodiment, but it is not necessary for the sound emission angle to be adjustable. For example, speaker 2B may be a speaker 2 in which the mechanism for rotating the movable plate 21 to which the speaker body 20 is attached (rotating shaft 210, guide pin 211, motor 22, guide member 23, belt 25, and motor drive unit 242) is omitted, as in speaker 2 in the first embodiment shown in Figure 8.

[0134] Here, speaker 2B-1 is provided for the C channel, speaker 2B-2 for the FL channel, speaker 2B-3 for the FR channel, speaker 2B-4 for the SL channel, speaker 2B-5 for the SR channel, speaker 2B-6 for the HL channel, and speaker 2B-7 for the HR channel.

[0135] The reflectors 4 are provided in accordance with each of the speakers 2B-1 to 2B-5 of each channel other than the height channels (HL channel and HR channel), and reflect the audio signal (including the test signal) emitted from the corresponding speaker 2B to reach the listening point P.

[0136] In the front area R1, reflector 4-1 is positioned below speaker 2B-1, reflector 4-2 is positioned below speaker 2B-2, and reflector 4-3 is positioned below speaker 2B-3. In the rear area R3, reflector 4-4 is positioned below speaker 2B-4, and reflector 4-5 is positioned below speaker 2B-5.

[0137] Figure 15 is a diagram illustrating the direction of propagation of audio signals emitted from speaker 2B-2, which supports FL channels, and speaker 2B-3, which supports FR channels.

[0138] As shown in the diagram, the tilt of the reflector 4-2 is adjusted so that the audio beam 40a-2 of the FL channel audio signal emitted downward from the FL channel speaker 2B-2 is reflected off the reflector 4-2 located below the FL channel speaker 2B-2 and reaches the listening point P from the user's left front. The tilt of the reflector 4-3 is adjusted so that the audio beam 40a-3 of the FR channel audio signal emitted downward from the FR channel speaker 2B-3 is reflected off the reflector 4-3 located below the FR channel speaker 2B-3 and reaches the listening point P from the user's right front.

[0139] Figure 16 is a diagram illustrating the direction of audio signal propagation emitted from speaker 2B-1 (C channel), speaker 2B-4 (SL channel), speaker 2B-5 (SR channel), speaker 2B-6 (HL channel), and speaker 2B-7 (HR channel).

[0140] As shown in the diagram, the tilt of reflector 4-1 is adjusted so that the audio beam 40a-1 of the C-channel audio signal emitted downward from speaker 2B-1 (C-channel compatible) is reflected off the reflecting surface of reflector 4-1, which is located below speaker 2B-1 (C-channel compatible), and reaches the listening point P from the user's front. Similarly, the tilt of reflectors 4-4 and 4-5 is adjusted so that the audio beams 40a-4 and 40a-5 of the SL-channel and SR-channel audio signals emitted downward from speaker 2B-4 (SL-channel compatible) and speaker 2B-5 (SR-channel compatible), respectively, are reflected off the reflecting surfaces of reflectors 4-4 and 4-5, which are located below speakers 2B-4 and 2B-5 (SL-channel compatible and SR-channel compatible), and reach the listening point P from the user's left rear and right rear, respectively. Then, speaker 2B-6, which is compatible with the HL channel, and speaker 2B-7, which is compatible with the HR channel, emit the audio beams 40a-6 and 40a-7 of the HL channel and HR channel audio signals downwards, respectively.

[0141] Figures 17(A) and 17(B) are schematic front and side views of the reflector 4.

[0142] As shown in the figure, the reflector 4 comprises a reflector body 40 having an audio signal reflective surface 400 on its surface, and a support rod 42 with one end attached to the back surface of the reflector body 40 via a hinge 41. The support rod 42 can be tilted at any angle relative to the back surface of the reflector body 40 by the hinge 41, and by placing one side of the reflector body 40 and the other end of the support rod 42 on the floor surface, the reflector body 40 can be supported with the reflective surface 400 tilted relative to the floor surface. The user can adjust the tilt angle of the reflective surface 400 relative to the floor surface to a desired angle by adjusting the tilt angle of the support rod 42 relative to the back surface of the reflector body 40.

[0143] The second embodiment of the present invention has been described above.

[0144] In this embodiment, as shown in Figures 15 and 16, audio signals emitted from speakers corresponding to channels other than the height channel (speakers 2B-1 to 2B-5 corresponding to the C channel, FL channel, FR channel, SL channel, and SR channel) are reflected by reflectors 4-1 to 4-5 placed below those speakers 2B-1 to 2B-5, and reach the user at listening point P from the direction (front, front left, front right, rear left, rear right) determined for each channel. Therefore, as with the first embodiment described above, even if these speakers 2B-1 to 2B-5 are installed on the ceiling, the same acoustic space as when they are installed on the floor in a standard configuration can be reproduced at listening point P. Furthermore, the reflectors 4 are thinner than the speakers 2B and can be easily moved. Therefore, compared to when the speakers 2B are installed on the floor, the room appears more spacious and uncluttered, and does not hinder the user's movement. Furthermore, when not using the multi-channel audio system, users can move the reflector 4 as needed, or put it away in a compact state with the support rod 42 folded, allowing for more comfortable and efficient use of the room.

[0145] Therefore, according to this embodiment, a higher quality acoustic space can be reproduced at the listening point while maintaining a comfortable indoor environment. Other effects are the same as those of the first embodiment described above.

[0146] It should be noted that the present invention is not limited to the embodiments described above, and numerous modifications are possible within the scope of its essence.

[0147] For example, in each of the above embodiments, during playback of multi-channel audio data, the wireless terminal 3 acquires the audio signals of each of the multiple channels wirelessly transmitted from the audio device 1 at the listening point P, and also collects the audio signals of each of the multiple channels emitted from the multiple speakers 2 and 2B. The wireless terminal 3 then extracts the signal components of each of the multiple channels' audio signals from these collected signals and monitors the difference between the extracted audio signal components and the audio signals wirelessly transmitted from the audio device 1 for each channel. If a channel with a difference fluctuation of a predetermined magnitude or larger is detected as a channel to be updated, the wireless terminal 3 determines the amount of adjustment for the output characteristics of the audio signal of the channel to be updated based on the difference fluctuation amount, and transmits an acoustic profile update instruction to the audio device 1, along with the determined audio signal adjustment amount and the specification of the channel to be updated. In response, the audio device 1 updates the acoustic profile information of the channel to be updated, which is specified by the acoustic profile update instruction received from the wireless terminal 3, according to the adjustment amount specified by this update instruction.

[0148] However, the present invention is not limited thereto. The wireless terminal 3 collects audio signals from multiple channels emitted from multiple speakers 2, 2B and transmits the collected signals to the audio device 1. The audio device 1 may extract the signal components of each of the multiple channels' audio signals from the collected signals received from the wireless terminal 3 based on the audio signals it has wirelessly transmitted, and monitor the difference between the extracted audio signal components and the audio signals it has wirelessly transmitted for each channel. If the audio device 1 detects a channel with a difference fluctuation amount greater than a predetermined amount as a channel to be updated, it determines the amount of adjustment for the output characteristics of the audio signal of the channel to be updated based on the difference fluctuation amount, and updates the acoustic profile information of the channel to be updated according to this adjustment amount.

[0149] Furthermore, in the embodiments described above, speakers 2, 2A, and 2B were ceiling-mounted types that are installed in mounting holes in the ceiling, but the present invention is not limited to these. Speakers 2, 2A, and 2B may be ceiling-mounted types or other types besides ceiling-mounted types, as long as they can be installed on the ceiling.

[0150] Furthermore, in each of the embodiments described above, a multi-channel audio system was used as an example to explain how to reproduce and output multi-channel audio data as audio signals for the C channel, FL channel, FR channel, SL channel, SR channel, HL channel, and HR channel. However, the present invention is not limited to this. The present invention is broadly applicable to multi-channel audio systems that reproduce and output multi-channel audio data as audio signals for multiple channels, including channels other than the height channel. [Explanation of Symbols]

[0151] 1: Audio equipment 2, 2A, 2B, 2-1~2-7, 2B-1~2B-7: Speakers 3: Wireless terminal 4, 4-1~4-5: Reflector 20, 270: Speaker body 21: Movable plate 22: Motor 23: Guide member 24, 28: Control unit 25: Belt 26, 29: Cabinet 27: Speaker array 40: Reflector body 41: Hinge 42: Mounting rod 100: Wireless network interface unit 101: Music acquisition unit 102: Content storage unit 103: Test signal sound source storage unit 104: Acoustic profile information storage unit 105: Audio playback unit 106: Output characteristic adjustment unit 107: Instruction receiving unit 108: Sound collection signal receiving unit 109: Measurement unit 110: Acoustic profile information generation unit 111: Main control unit 210: Rotating shaft 211: Guide pin 230: Slit 240, 280: Wireless network interface section 241, 281: Speaker drive unit; 242: Motor drive unit 260: Opening 261: Bolt 282: Speaker switching section 290: Speaker surface 291: Mounting part 300: Wireless network interface unit 301: Human-machine interface section 302: Audio signal acquisition section 303: Sound collection microphone 304: Channel extraction unit 305: Difference monitoring unit 306: Adjustment amount determination unit 307: Sound collection signal transmission unit 308: Instruction transmission unit 309: Main control unit 400: Reflective surface

Claims

1. A multichannel audio system comprising an audio device that reproduces and outputs multichannel audio data as multiple channel audio signals, and a plurality of speakers provided corresponding to each of the multiple channels, The aforementioned multiple speakers are installed on the ceiling of the room and each emits an audio signal of its corresponding channel, which is output from the audio device. Of the multiple speakers mentioned above, the sound emission direction of the speakers corresponding to channels other than the height channel is set so that the audio signal emitted from the speaker reflects off the walls of the room and reaches the listening point set in the room from a direction determined for the channel corresponding to that speaker. A multi-channel audio system characterized by the following features.

2. A multi-channel audio system according to claim 1, Speakers corresponding to channels other than the aforementioned height channel are: It has an adjustment mechanism that adjusts the emission angle of the audio signal according to instructions received from an external source or manually. A multi-channel audio system characterized by the following features.

3. A multi-channel audio system according to claim 1, Speakers corresponding to channels other than the aforementioned height channel are: Multiple speaker sections with different sound emission directions, It includes a selection unit that, in accordance with instructions received from an external source, selects a speaker unit from among the plurality of speaker units to emit the audio signal. A multi-channel audio system characterized by the following features.

4. A multi-channel audio system according to claim 1, Of the plurality of speakers, the sound emission direction of the first speaker corresponding to the center channel is set so that the audio signal emitted from the first speaker reflects off the wall located in front of the user at the listening point and reaches the listening point from in front of the user; the sound emission direction of the second speaker corresponding to the front left channel is set so that the audio signal emitted from the second speaker reflects off the wall located to the left of the user at the listening point and reaches the listening point from the left front of the user; and the sound emission direction of the third speaker corresponding to the front right channel is set so that the audio signal emitted from the third speaker reflects off the wall located to the right of the user at the listening point and reaches the listening point from the right front of the user. A multi-channel audio system characterized by the following features.

5. A multichannel audio system comprising an audio device that reproduces and outputs multichannel audio data as multiple channel audio signals, and a plurality of speakers provided corresponding to each of the multiple channels, The aforementioned plurality of speakers have a plurality of reflectors provided for the speakers corresponding to channels other than the height channel, The aforementioned multiple speakers are, They are installed on the ceiling of the room and each emits the audio signal of the channel corresponding to the speaker, output from the aforementioned audio device, downwards. Each of the plurality of reflectors is positioned in the room below the speaker corresponding to the reflector, and reflects the audio signal emitted from the speaker so that it reaches the listening point set in the room from a direction determined with respect to the channel corresponding to the speaker. A multi-channel audio system characterized by the following features.

6. A multichannel audio system according to claim 5, Of the plurality of reflectors, the first reflector is positioned below the speaker corresponding to the center channel and reflects the audio signal emitted from the speaker so that it reaches the listening point from directly in front of the user at the listening point; the second reflector is positioned below the speaker corresponding to the front left channel and reflects the audio signal emitted from the speaker so that it reaches the listening point from the left front of the user; and the third reflector is positioned below the speaker corresponding to the front right channel and reflects the audio signal emitted from the speaker so that it reaches the listening point from the right front of the user. A multi-channel audio system characterized by the following features.

7. A multichannel audio system according to any one of claims 1 to 6, With an additional remote controller, The audio device wirelessly transmits the audio signals of the multiple channels. Each of the aforementioned speakers receives an audio signal of its corresponding channel, which is wirelessly transmitted from the audio device, and emits sound. The aforementioned remote controller A sound-collecting microphone and Receiving means for receiving the multiple-channel audio signals wirelessly transmitted from the audio device, For each of the aforementioned multiple channels, an extraction means for extracting the signal component of the audio signal of that channel received by the receiving means from the sound collection signal of the sound collection microphone, For each of the aforementioned multiple channels, a monitoring means monitors the difference between the audio signal of the channel received by the receiving means and the signal component of the audio signal of the channel extracted by the extraction means. For each of the aforementioned multiple channels, a determination means for determining the amount of adjustment of the audio signal of that channel based on the difference change monitored by the monitoring means, The system includes a transmission means for transmitting a setting instruction to the audio device, which includes the amount of adjustment of the audio signal determined by the determination means and the specification of the target channel of the audio signal. The aforementioned audio device is The system includes an adjustment means for adjusting the audio signal of the channel specified by the setting instruction received from the remote controller, according to the adjustment amount specified by the setting instruction. A multi-channel audio system characterized by the following features.

8. A multichannel audio system according to any one of claims 1 to 6, With an additional remote controller, The audio device wirelessly transmits the audio signals of the multiple channels. Each of the aforementioned speakers receives an audio signal of its corresponding channel, which is wirelessly transmitted from the audio device, and emits sound. The aforementioned remote controller A sound-collecting microphone and It has a transmitting means for transmitting the sound collection signal from the sound collection microphone to the audio device, The aforementioned audio device is For each of the aforementioned multiple channels, an extraction means for extracting the signal component of the audio signal for that channel from the sound collection signal received from the remote controller, For each of the aforementioned multiple channels, a monitoring means is provided to monitor the difference between the audio signal of that channel and the signal component of the audio signal of that channel extracted by the extraction means. For each of the aforementioned multiple channels, a determination means for determining the amount of adjustment of the audio signal of that channel based on the difference change monitored by the monitoring means, The system includes an adjustment means that, once the adjustment amount for the audio signal of any channel has been determined by the determination means, adjusts the audio signal of that channel according to the determined adjustment amount. A multi-channel audio system characterized by the following features.

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