JP4937942B2 - Audio reproduction device, audio reproduction method, audio reproduction system, control program, and computer-readable recording medium - Google Patents

Description

  The present invention relates to an audio reproducing apparatus, an audio reproducing method, an audio reproducing system, a control program, and a computer-readable recording medium that reproduce audio through a speaker including a plurality of speaker units such as a polyhedral speaker.

  Currently, television is often used mainly in scenes where users watch movies and television programs carefully. However, when considering the viewing situation of a TV with a large screen exceeding 100 inches, for example, a natural image can be displayed casually in BGM, or as if there is another room or outdoor scene. Use scenes that have never existed, such as displaying them. In that case, the relationship between the screen position and the viewing position is more flexible than a television with a small screen.

  For example, in the case of a TV with a small screen, the user needs to be positioned near the TV screen in order to view the displayed image. However, if the screen is large, the user can view the image sufficiently even if the screen is far away. it can. In addition, when a natural video is displayed in a BGM manner as described above, the user is not in a situation of watching the video carefully, and is not necessarily located near the screen. Absent.

  For this reason, in the case of a television in which a speaker and a screen are integrally provided, a user who is located away from the screen cannot hear sound at a normal volume. In addition, when the volume is increased so that a user away from the screen can hear the sound of the television, the volume is too large for the user who is viewing the television near the screen, and the user cannot view comfortably.

  In such a situation, it is not necessary to provide the speaker and the screen integrally. For example, by arranging a wireless speaker in the center of the room or by arranging a plurality of speakers in various places in the room, the speaker and the screen are not provided. It is also possible to consider a configuration in which these are provided independently.

  By the way, in recent years, polyhedral speakers have been used. For example, Patent Document 1 discloses an acoustic device in which a plurality of speakers are arranged on the circumference within a single casing, and automatically adjusted so that a correct sound image is obtained for a listener who operates the remote controller. .

  In the configuration of Patent Literature 1, in order to realize multi-channel surround reproduction, a configuration is disclosed in which audio signals of different channels are supplied to the respective speaker units constituting the polyhedral speaker, and different audio is reproduced by the respective speaker units. However, a configuration in which the same sound signal is supplied to each speaker unit constituting the polyhedral speaker and the same sound is reproduced in each speaker unit is also conceivable.

In order to realize a more comfortable viewing environment in the above-described large-screen television exceeding 100 inches, it is conceivable to apply a polyhedral speaker.
JP-A-8-182098 (published July 12, 1996)

  However, the above polyhedral speaker is applied to a large-screen television, and the same audio signal having the same phase and amplitude is supplied to each speaker unit constituting the polyhedral speaker to reproduce the same sound in each speaker unit. Since each speaker unit is facing a different direction, the sound output from each speaker unit is different in the distance from each speaker unit to the position of the listener, due to the influence of room reflection, etc. As a result, the listener reaches as a sound having a different phase and amplitude. In addition, the frequency characteristics of the high frequency drop as the position deviates from the center of the speaker due to the directivity characteristics of the speaker.

  FIG. 11 is a diagram showing an image of a waveform of an original sound reproduced by a polyhedral speaker, a waveform at a listening position of a sound output from each speaker unit, and a synthesized waveform thereof. FIG. 11A is a diagram showing an image of the waveform of the original sound, and FIG. 11B is a diagram showing an image of the waveform at the listening position of the sound output from the front speaker unit, and FIG. FIG. 11 is a diagram illustrating an image of a waveform at a listening position of a sound output from the speaker unit on the side surface, and FIG. 11D is a diagram illustrating an image of a waveform at a listening position of the sound output from the speaker unit on the back surface. FIG. 11E is a diagram showing an image of a waveform obtained by synthesizing the waveforms of (b) to (d). As shown in FIG. 11 (b), the waveform of the sound output from the front speaker unit is substantially the same as the original sound at the listening position, and is substantially similar to the original sound. Further, as shown in FIGS. 11C and 11D, the sound waveform output from the side speaker unit and the rear speaker unit has a high frequency component deteriorated by the influence of the directivity, and the signal does not rise. Maru. Then, the sound waveform at the listening position, that is, the sound waveform obtained by synthesizing the waveforms shown in FIGS. 11B to 11D greatly changes from the waveform shown in FIG. 11A, as shown in FIG. You can see that Although FIG. 11 shows an image of the waveform of the sound that directly reaches the listening position from the speaker unit, actually, the reflected sound from the wall or floor also reaches the listening position.

  As a result, since the reflected sound from the wall and floor is synthesized at the listener's position, sounds of different phases and amplitudes are synthesized. Therefore, the rounding of the waveform is further deteriorated, and further, fluctuations in the amplitude also occur, so that there is a problem that sound clarity is lost and a comfortable acoustic environment for the listener cannot be realized.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to impair the clarity of sound at a listening position when sound is output by a speaker including a plurality of speaker units. It is an object of the present invention to provide an audio reproducing device, an audio reproducing method, an audio reproducing system, a control program, and a computer-readable recording medium that can realize a comfortable acoustic environment for a listener.

  An audio reproduction device according to the present invention is an audio reproduction device that controls audio output via a plurality of speakers each including a plurality of speaker units, and outputs audio from the plurality of speaker units for each of the speakers. Selecting means for selecting a plurality of speaker units, and for each of the speakers, the phases of all the sounds output from the plurality of speaker units selected by the selection means are equal at the listening position of the user. The first delay means for delaying the supply of the audio signal to each speaker unit is provided.

  According to said structure, an audio | voice reproduction apparatus reproduces | regenerates an audio | voice via a some speaker. And each speaker is comprised by several speaker units, such as a polyhedral speaker, for example.

  Moreover, according to said structure, a selection means selects the speaker unit which outputs an audio | voice from the speaker units which comprise a speaker for every said speaker. Here, the selection means may be a configuration that unconditionally selects all speaker units constituting the speaker as a speaker unit that outputs sound, a configuration that selects a plurality of predetermined speaker units, or a predetermined configuration. There may be a configuration in which a plurality of speaker units satisfying the above conditions are selected, and there is no particular limitation.

  Further, according to the above configuration, the first delay unit causes the phases of all the sounds output from the plurality of speaker units selected by the selection unit to be equal at the listening position of the user for each speaker. In addition, the supply of the audio signal to each speaker unit is delayed. For example, the audio signal supplied for each speaker unit is set so that the sound output from the other speaker unit also reaches the listening position at the timing when the sound output from the speaker unit farthest from the listening position reaches the listening position. Delay. Alternatively, the supply of audio signals may be delayed for each speaker unit so that the audio output from each speaker unit reaches the listening position at a predetermined delay time, and there is no particular limitation.

  In other words, in the sound reproducing device according to the present invention, in one speaker constituted by a plurality of speaker units, the phases of the sound output from the plurality of speaker units selected by the selection unit are all at the listening position of the user. Be the same. Therefore, a plurality of sounds having different phases do not reach the listening position from one speaker.

  As a result, the rounding of the sound pressure waveform reaching the listener's ear can be reduced, and the user can listen to sound with clear sound quality. Therefore, a comfortable acoustic environment for the user can be realized.

  An audio reproduction method according to the present invention is an audio reproduction method for outputting audio through a plurality of speakers each including a plurality of speaker units, and outputs audio from the plurality of speaker units for each speaker. A selection step of selecting a plurality of speaker units, and for each speaker, the phases of all the sounds output from the plurality of speaker units selected by the selection means are equal at the listening position of the user, respectively. A first delay step for delaying the supply of the audio signal to the speaker unit is included.

  According to said structure, there exists an effect similar to the audio | voice reproduction apparatus based on this invention.

  In the sound reproducing device according to the present invention, the phases at the listening position of the sound output from the plurality of speaker units selected for each of the speakers by the selecting unit are all equal between the plurality of speakers. It is preferable to further include second delay means for delaying the supply of the audio signal to the speaker unit.

  In other words, when two different speakers arbitrarily selected from the plurality of speakers are defined as the first and second speakers, respectively, the plurality of speaker units selected in the first speaker by the selection unit. Each speaker unit is configured such that the phase of the output sound at the listening position is all equal to the phase of the sound output from the plurality of speaker units selected by the selection means in the second speaker. It is preferable to further include second delay means for delaying the supply of the audio signal to the.

  According to the above configuration, sound is reproduced from a plurality of speakers including a plurality of speaker units, but the second delay means is configured so that the phases of the sounds output from the speakers are all equal at the listening position. The supply of the audio signal to each speaker unit selected for each speaker by the selection means is delayed. That is, the second delay means equalizes the phase of the sound output from all the speakers at the listening position. Therefore, a plurality of sounds with different phases do not reach the listening position from the plurality of speakers.

  As a result, the sound output from each speaker does not synthesize a plurality of sounds having different phases at the listening position, so that the rounding of the sound pressure waveform reaching the listener's ear can be further reduced. The user can listen to a sound with clear sound quality.

  The audio reproducing apparatus according to the present invention further includes first amplitude adjusting means for individually changing the magnitudes of the audio signals supplied to the plurality of speaker units selected by the selecting means for each of the speakers. Preferably it is.

  According to said structure, the 1st amplitude adjustment means can change the magnitude | size of the audio | voice signal supplied to the several speaker unit selected by the selection means separately for every said speaker, respectively. .

  Thus, for example, when correcting the frequency characteristics for each speaker unit, the gain of the audio signal supplied to each speaker unit is set so that the corrected audio signal input to the DAC is not digitally clipped. It becomes possible to adjust. Therefore, since digital clipping can be prevented and generation of large noise can be suppressed, a comfortable acoustic environment for the user can be realized.

  In the audio reproducing apparatus according to the present invention, the sum of the amplitudes at the listening position of the audio output from the plurality of speaker units selected for each of the speakers by the selection unit is all equal between the plurality of speakers. Preferably, the apparatus further includes second amplitude adjusting means for changing the magnitude of the audio signal supplied to each speaker unit.

  In other words, in the audio reproduction device according to the present invention, when the two different speakers arbitrarily selected from the plurality of speakers are the first and second speakers, respectively, the first speaker is selected by the selection means. The sum of the amplitude at the listening position of the sound output from the plurality of speaker units selected from the above is the amplitude at the listening position of the sound output from the plurality of speaker units selected by the selection means from the second speaker. It is preferable to further include second amplitude adjusting means for changing the magnitude of the audio signal supplied to each speaker unit so as to be all equal to the sum of.

  According to the above configuration, the sound is reproduced from the plurality of speakers including the plurality of speaker units. The second amplitude adjusting unit is configured such that the sum of the amplitudes of the sounds output from the speaker units of the respective speakers is the listening position. The supply of the audio signal to each speaker unit selected for each speaker by the selection means is delayed so that they are all equal. That is, the second delay means equalizes the sum of the amplitudes of the sounds output from the speaker units of all the speakers at the listening position. Therefore, the total output from the plurality of speakers is equal between the speakers at the listening position.

  As a result, the sound output from each speaker does not synthesize a plurality of sounds having different overall outputs at the listening position, thereby further reducing the rounding of the sound pressure waveform reaching the listener's ear. The user can listen to the sound with clear sound quality.

  In the audio reproduction device according to the present invention, for each speaker, the amplitude frequency characteristics of all sounds output from the plurality of speaker units selected by the selection unit are at least in an audible frequency band at the user's listening position. It is preferable to further include frequency characteristic correction means for imparting correction characteristics to the audio signals supplied to the respective speaker units so as to be substantially constant.

  According to the above configuration, the frequency characteristic correcting unit is configured such that, for each speaker, the amplitude frequency of all sounds output from the plurality of speaker units selected by the selecting unit is at least an audible frequency at the position of the user. Correction characteristics are imparted to the audio signals supplied to the respective speaker units so as to be substantially constant in the band. The frequency characteristic correction means may be configured as, for example, a multi-band equalizer (IIR filter) to give an inverse characteristic to the audio signal, or may be configured as an FIR filter to represent the correction characteristic. There may be a configuration in which the frequency characteristic is corrected by performing a convolution operation on the audio signal with respect to the filter coefficient, and there is no particular limitation. Note that the amplitude frequency characteristic may be flat in the entire frequency band, and is not particularly limited.

  As a result, the sound output from each speaker unit constituting the speaker has a flat amplitude frequency characteristic in which the peak and dip of the amplitude frequency characteristic are canceled at the listening position. Can play audio.

  In the audio reproduction device according to the present invention, it is preferable that the selection unit selects a predetermined number of speaker units in the order close to the listening position for each speaker.

  According to said structure, the said selection means selects the some speaker unit of the predetermined number in order close to the said listening position for every said speaker. Here, the number of speaker units selected by the selection unit may be set every time by the user. The number of selected speaker units may be the same for all speakers or may be different for each speaker, and is not particularly limited. The configuration in which the speaker units are selected in order from the listening position is, for example, the configuration in which the sound output from each speaker unit is measured at the listening position based on the same audio signal and is selected in descending order of the amplitude of the sound. Alternatively, the selection may be made in ascending order of delay amount with respect to the original signal of the sound, and there is no particular limitation.

  As a result, since a predetermined number of speaker units are selected, the load in the process of changing the magnitude of the audio signal supplied to each speaker unit is reduced as compared with the case where all the speaker units are selected. Is done. In addition, since the speaker units are selected in order from the closest to the listening position, it is possible to reduce the influence of reflection due to walls, floors, etc., compared to the case where all the speaker units are selected.

  An audio reproduction device according to the present invention is an audio reproduction device that outputs audio through a speaker including a plurality of speaker units, and selects a plurality of speaker units that output audio from the plurality of speaker units. The supply of audio signals to each speaker unit is delayed so that the phases of all audio output from the selection unit and the plurality of speaker units selected by the selection unit are equal at the listening position of the user. A delay means is provided.

  According to said structure, an audio | voice reproduction apparatus outputs an audio | voice via the speaker comprised by several speaker units, such as a polyhedral speaker, for example. Here, the number of speakers that output sound is not limited to a plurality.

  Moreover, according to said structure, a selection means selects the speaker unit which outputs an audio | voice from the speaker units which comprise a speaker. Here, the selection means may be a configuration that unconditionally selects all speaker units constituting the speaker as a speaker unit that outputs sound, a configuration that selects a plurality of predetermined speaker units, or a predetermined configuration. There may be a configuration in which a plurality of speaker units satisfying the above conditions are selected, and there is no particular limitation.

  Further, according to the above configuration, the first delay unit is configured so that the phases of all the sounds output from the plurality of speaker units selected by the selection unit are equal at the listening position of the user. Delay the supply of audio signals to the unit. For example, the audio signal supplied for each speaker unit is set so that the sound output from the other speaker unit also reaches the listening position at the timing when the sound output from the speaker unit farthest from the listening position reaches the listening position. Delay. Alternatively, the supply of audio signals may be delayed for each speaker unit so that the audio output from each speaker unit reaches the listening position at a predetermined delay time, and there is no particular limitation.

  In other words, in the sound reproducing device according to the present invention, in one speaker constituted by a plurality of speaker units, the phases of the sound output from the plurality of speaker units selected by the selection unit are all at the listening position of the user. Be the same. Therefore, a plurality of sounds having different phases do not reach the listening position from one speaker.

  As a result, the rounding of the sound pressure waveform reaching the listener's ear can be reduced, and the user can listen to sound with clear sound quality. Therefore, a comfortable acoustic environment for the user can be realized.

  The audio reproduction method according to the present invention is an audio reproduction method for outputting audio via a speaker composed of a plurality of speaker units, wherein a plurality of speaker units that output audio are selected from the plurality of speaker units. The supply of audio signals to the respective speaker units is delayed so that the phases of all audio output from the selection step and the plurality of speaker units selected in the selection step are equal at the listening position of the user. And a delay step.

  According to said structure, there exists an effect similar to the audio | voice reproduction apparatus based on this invention.

  The audio reproducing apparatus according to the present invention preferably further includes amplitude adjusting means for individually changing the magnitudes of the audio signals supplied to the plurality of speaker units selected by the selecting means.

  In other words, in the audio reproduction device according to the present invention, each speaker unit is set such that the amplitudes of all the audios output from the plurality of speaker units selected by the selection unit are equal at the listening position of the user. It is preferable to further include amplitude adjusting means for changing the magnitude of the audio signal supplied to the.

  According to the above configuration, the amplitude adjusting unit can individually change the magnitudes of the audio signals supplied to the plurality of speaker units selected by the selecting unit.

  Thus, for example, when correcting the frequency characteristics for each speaker unit, the gain of the audio signal supplied to each speaker unit is set so that the corrected audio signal input to the DAC is not digitally clipped. It becomes possible to adjust. Therefore, since digital clipping can be prevented and generation of large noise can be suppressed, a comfortable acoustic environment for the user can be realized.

  In the sound reproducing device according to the present invention, the amplitude frequency characteristics of all sounds output from the plurality of speaker units selected by the selecting means are substantially constant at least in the audible frequency band at the user's listening position. In addition, it is preferable to further include frequency characteristic correction means for imparting correction characteristics to the audio signal supplied to each speaker unit.

  According to the above configuration, the frequency characteristic correcting unit is configured such that the amplitude frequencies of all sounds output from the plurality of speaker units selected by the selecting unit are substantially constant at least in an audible frequency band at the user's position. Thus, a correction characteristic is given to the audio signal supplied to each speaker unit. The frequency characteristic correction means may be configured as, for example, a multi-band equalizer (IIR filter) to give an inverse characteristic to the audio signal, or may be configured as an FIR filter to represent the correction characteristic. There may be a configuration in which the frequency characteristic is corrected by performing a convolution operation on the audio signal with respect to the filter coefficient, and there is no particular limitation. Note that the amplitude frequency characteristic may be flat in the entire frequency band, and is not particularly limited.

  As a result, the sound output from each speaker unit constituting one speaker cancels out the peak and dip of the amplitude frequency characteristic at the listening position and becomes a flat amplitude frequency characteristic. Sound can be played faithfully.

  The audio reproduction system according to the present invention collects the audio reproduction apparatus and the audio output from the audio reproduction apparatus, converts the collected audio into an electrical reception signal, and outputs the electric reception signal to the audio reproduction apparatus And a microphone to be used.

  According to said structure, the said audio | voice reproduction apparatus supplies an audio | voice signal with respect to the said speaker. From each speaker unit, sound is output based on the sound signal supplied to the speaker. Further, the microphone outputs sound output from each speaker unit, converts the sound into a received signal, and outputs the received signal to the sound reproducing device. And, based on the reception signal of the sound from each speaker unit collected by the microphone, the sound reproduction device, the amplitude and delay at the listening position of the sound output from each speaker unit is the same, Control audio output.

  Thereby, since the rounding of the sound pressure waveform reaching the listener's ear can be reduced, the user can listen to the sound with clear sound quality. Therefore, according to the audio reproduction system of the present invention, an acoustic environment comfortable for the user can be realized.

  Further, the sound reproducing device may be realized by a computer. In this case, a control program for realizing the sound reproduction apparatus in the computer by operating the computer as each of the above means and a computer-readable recording medium on which the control program is recorded also fall within the scope of the present invention.

  An audio reproduction apparatus according to the present invention is an audio reproduction apparatus that outputs audio through a plurality of speakers each including a plurality of speaker units, and outputs audio from the plurality of speaker units for each of the speakers. Selection means for selecting a plurality of speaker units, and for each speaker, the phases of all the sounds output from the plurality of speaker units selected by the selection means are equal at the listening position of the user, respectively. The first delay means for delaying the supply of the audio signal to the speaker unit is provided.

  An audio reproducing apparatus according to the present invention is an audio reproducing apparatus that outputs audio through a speaker including a plurality of speaker units, and includes a plurality of speaker units that output audio from the plurality of speaker units. The audio signal is supplied to each speaker unit so that the phase of all audio output from the selection unit to be selected and the plurality of speaker units selected by the selection unit is equal at the listening position of the user. It is characterized by comprising delay means for delaying.

  Thereby, since a plurality of sounds having different phases do not reach the listening position from one speaker, the rounding of the sound pressure waveform reaching the listener's ear can be reduced. It becomes possible to listen to sound with clear sound quality.

  The sound reproducing device 1 according to the present invention will be described below with reference to FIGS.

(Audio playback device 1)
FIG. 1 is a block diagram showing the configuration of an audio playback device 1 according to the present invention. As shown in FIG. 1, an audio reproduction device 1 includes an input terminal 2, an analog / digital converter (ADC) 3, a delay circuit 4 (first delay means, second delay means), and a frequency correction unit 5 (frequency characteristic correction means). Gain adjustment unit 6 (first amplitude adjustment unit, second amplitude adjustment unit), selection circuit 7, digital analog converter (DAC) 8, amplifier 9, test signal generation circuit 11, delay amount detection unit 12, and amplitude detection unit 13 An analog-digital converter (ADC) 14, a control unit 15, and a memory 16 are included.

  The delay circuit 4 includes delay circuits 4a to 4f. The frequency characteristic correction unit 5 includes frequency characteristic correction units 5a to 5f. The gain adjusting unit 6 includes gain adjusting units 6a to 6f. The DAC 8 includes the DACs 8a to 8f. The amplifier 9 includes amplifiers 9a to 9f.

  Further, as shown in FIG. 1, a speaker 17 is connected to the audio reproduction device 1. The speaker 17 includes speaker units 17a, 17b, 17c, 17d, 17, and 17f. The appearance of the speaker unit is a hexahedral shape as shown in FIG. 2, and the speaker units 17a to 17f are arranged on each of the six surfaces.

  FIG. 2 is a diagram illustrating a configuration of the audio reproduction system 100. As shown in FIG. 2, the audio reproduction device 1 constitutes an audio reproduction system 100 together with speakers 17 and 17 ′ and a microphone 18. In the present embodiment, the audio reproduction device 1 supplies an audio signal to the speakers 17 and 17 ′ wirelessly. Similarly, the audio reproduction device 1 receives an audio signal from the microphone 18 by radio. However, the audio reproduction device 1 may be configured to be connected to the speakers 17 and 17 ′ and the microphone 18 through a communication cable, and is not particularly limited. In the present embodiment, the audio playback device 1 is configured to receive an audio signal from the outside, but may be configured to have a playback function of a compact disc or a cassette tape, and is not particularly limited.

  In the present embodiment, the audio reproduction system 100 is configured as a stereo reproduction system, and an L-channel audio signal and an R-channel audio signal are input to the music reproduction apparatus 1. The speaker 17 outputs sound based on the L channel audio signal, and the speaker 17 'outputs sound based on the R channel audio signal. Further, the microphone 18 can collect the sound output from the speakers 17 and 17 ′ and convert it into an electrical sound signal. In the present embodiment, the same L channel signal is supplied to the speaker units 17a to 17f constituting the hexahedral speaker 17. Similarly, the same R channel signal is supplied to the speaker units 17'a to f constituting the speaker 17 '. That is, it is not a configuration in which an audio signal of a different channel is supplied to each speaker unit in one speaker.

  Below, the outline | summary of the function of each part which comprises the audio | voice reproduction apparatus 1 is demonstrated. In FIG. 1, only the speaker 17 is shown for the sake of simplicity, and only the configuration for controlling the sound reproduction of the L-channel audio signal is shown. However, the sound reproducing apparatus 1 uses the R-channel audio signal. The sound reproduction is controlled by the same configuration.

  The input terminal 2 is a terminal for inputting an external audio signal to the sound reproducing apparatus 1. The ADC 3 converts an L-channel audio input signal, which is an analog signal input via the input terminal 2, into an L-channel digital signal (hereinafter referred to as an Lch signal) and outputs it to the selection circuit 7. In the music reproducing apparatus 1, an R channel audio input signal is converted into an R channel digital signal (hereinafter referred to as an Rch signal).

  In the audio reproduction device 1, the test audio is reproduced via the speaker 17 based on the test signal generated by the test signal generation circuit 11. At this time, the test signal generation circuit 11 outputs a test signal to the selection circuit 7. Test signal data representing the test signal is stored in the memory 16 and is supplied to the test signal generation circuit 11 by the control unit 15. In the present embodiment, the test signal is generated as one signal supplied to the speaker units 17a to 17f in a time division manner.

  The selection circuit 7 selects which of the Lch signal from the ADC 3 and the test signal from the test signal generation circuit 11 is output based on the control signal from the control unit 15, and sends the selected signal to the delay circuit 4. Output.

  The delay circuit 4 delays the Lch signal and outputs it to the frequency characteristic correction unit 5. The frequency characteristic correction unit 5 corrects the frequency characteristic of the Lch signal and outputs it to the gain adjustment unit 6. The frequency characteristic correction unit 5 filters the Lch signal so as to obtain a desired frequency characteristic, and adjusts the gain of the Lch signal in a specific frequency region. The gain adjustment unit 6 adjusts the gain of the entire Lch signal and outputs it to the DAC 8. When the selection circuit 7 selects an Lch signal that is a digital signal, the DAC 8 converts the signal into an analog Lch signal and outputs the analog Lch signal to the amplifier 9. Further, when a test signal that is a digital signal is selected, the DAC 8 converts the test signal into an analog test signal and outputs the analog test signal to the amplifier 9. The amplifier 9 amplifies the Lch signal or the test signal and outputs it to the speaker 17.

  In the present embodiment, the delay circuit 4, the frequency characteristic correction unit 5, the gain adjustment unit 6, the DAC 8, and the amplifier 9 include the delay circuit 4 a corresponding to the speaker units 17 a to 17 f constituting the speaker 17. -F, frequency characteristic correction units 5a-f, gain adjustment units 6a-f, DACs 8a-f, and amplifiers 9a-f, each of the speaker units has a corresponding delay circuit 4, frequency characteristics, respectively. An audio signal is supplied through the correction unit 5, the gain adjustment unit 6, the DAC 8, and the amplifier 9.

  In the present embodiment, the selection of the speaker unit that outputs sound is realized by adjusting the gain in the gain adjusting unit 6 according to the control signal from the control unit 15. For example, when outputting sound only from the speaker unit 17a, the gain is set to 0 in the gain adjusting unit 6 provided corresponding to the speaker units 17b to 17f and supplied to the speaker units 17b to 17f. Set the audio signal size to zero. That is, the selection means in the claims is realized by the gain adjusting unit 6 and the control unit 15. The selection of the speaker unit is not limited to the configuration in which the gain is adjusted for each speaker unit, and the supply of the audio signal itself to the unselected speaker units is performed according to the control signal from the control unit 15. A configuration using a dedicated circuit for stopping may be used, and is not particularly limited.

  Further, when a test signal is output from the amplifier 9, the test signal supplied to the speaker units 17a to 17f is supplied in a time division manner with one signal. In this case, the gain adjustment unit 6 sequentially switches the speaker units that output the test sound in accordance with the timing at which the test signal corresponding to each speaker unit is supplied based on the control signal from the control unit 15.

  The microphone 18 picks up the test sound output from the speaker 17 (that is, the test sound sequentially output from the speaker units 17a to 17f) and converts it into an electrical signal (hereinafter referred to as a reception signal). The data is output to the ADC 14 via a microphone input interface (not shown). The ADC 14 converts the received signal from an analog signal to a digital signal and outputs the converted signal to the amplitude detector 13. Further, the amplitude detection unit 13 detects the maximum value of the amplitude of the received test sound signal output from the speaker units 17 a to 17 f and collected by the microphone 18, and outputs the detection result to the control unit 15. The received signal is output to the delay amount detection unit 12. Further, the delay amount detection unit 12 detects the delay amount with respect to the test signal that is the original signal of the test sound for the test sound reception signal from each speaker unit, and outputs the detection result to the control unit 15. In the present embodiment, the delay amount detection unit 12, the amplitude detection unit 13, and the control unit 15 are realized by a microcomputer. The delay amount detection unit 12 and the amplitude detection unit 13 may be configured as dedicated circuits, and are not particularly limited.

  And the audio | voice reproduction apparatus 1 which concerns on this invention selects the several speaker unit which outputs an audio | voice among the speaker units 17a-f which comprise the speaker 17, and the phase of the audio | voice from the selected speaker unit is a listening position. In the configuration of controlling to be equal to each other.

  In addition, the audio reproduction device 1 according to the present invention outputs the maximum value detection result from the amplitude detection unit 13 or the delay amount detection unit 12 when outputting a sound using a plurality of speakers including a plurality of speaker units. By delaying the Lch signal in the delay circuit 4, correcting the frequency characteristic of the Lch signal in the frequency characteristic correcting unit 5, and adjusting the gain of the Lch signal in the gain adjusting unit 6 based on the detection result of the delay amount Also, the configuration for controlling the audio output between the speakers has a feature.

  Below, the characteristic structure of the audio | voice reproduction apparatus 1 which concerns on this invention is demonstrated in detail.

(Speaker unit selection)
In the audio reproduction device 1 according to the present invention, when selecting a speaker unit that outputs audio, a test signal is output from each speaker unit based on the test signal, and a received signal obtained by collecting the sound by the microphone 18 To detect.

  3A and 3B are diagrams for explaining selection of the speaker unit. FIG. 3A is a diagram showing time waveforms of test signals supplied to the speaker units 17a to 17f constituting the speaker 17, and FIG. These are figures which show the time waveform of the received signal in the microphone 18. FIG.

  The horizontal axes of FIGS. 3A and 3B indicate time. As shown in FIG. 3A, each of the test signals supplied to the speaker units 17a to 17f is for one cycle of the sine wave, and the waveform itself is the same, but the phase is the speaker units 17a, 17b, 17c, 17d, 17e, and 17f are delayed in order of test signals. That is, one cycle of the sine wave included in the test signal is supplied in order of the speaker units 17a, 17b, 17c, 17d, 17e, and 17f. Further, as described above, the test signal data representing the test signal is stored in the memory 16, but the test signal data may be stored by compressing audio signal data representing the test signal itself, for example. Alternatively, it may be stored as a parameter representing the amplitude or frequency of the test signal, and is not particularly limited.

  When the test sound is reproduced, the control unit 15 reads the test signal data from the memory 16 and supplies the test signal data to the test signal generation circuit 11. Then, the test signal generation circuit 11 generates a test signal based on the supplied test signal data. For example, when the test signal data is compressed audio signal data, the test signal generation circuit 11 performs decoding processing and performs audio signal expansion processing. When the test signal data is a parameter, the test signal generation circuit 11 generates a signal having a waveform specified by the parameter.

  In this case, the control unit 15 supplies a control signal that instructs the selection circuit 7 to output a test signal. As a result, the selection circuit 7 outputs a test signal, and an analog test signal is supplied to the speaker 17 via the delay circuit 4, the frequency characteristic correction unit 5, the gain adjustment unit 6, the DAC 8, and the amplifier 9. Is done.

  As described above, the test signals supplied to the speaker units 17a to 17f are configured to be supplied in a time-sharing manner by one signal, and the control unit 15 performs a test corresponding to each speaker unit with respect to the gain adjusting unit 6. A control signal for instructing the gain of the audio signal other than the speaker unit outputting the test audio to be zero is supplied according to the timing at which the signal is supplied.

  The test sound may be played back when the user performs an operation to start listening to the sound playback device 1, or the user's operation using a remote controller (not shown) or the like may be performed. The configuration may be performed according to the method, and is not particularly limited.

  Further, the speaker units 17a to 17f sequentially output test sounds based on the test signal shown in FIG. The microphone 18 collects the test sound output from the speakers 17a to 17f and converts it into a reception signal shown in FIG. The received signal shown in FIG. 3B shows an example in the case where the microphone 18 is arranged at the position shown in FIG. That is, the received signal shown in FIG. 3B shows a waveform when the microphone 18 is arranged in front of the speaker unit 17 a constituting the speaker 17. As shown in FIG. 3B, the received signal includes six waveforms for one cycle of sine waves having different amplitudes. The waveform for one cycle of each sine wave shown in FIG. 3 (b) corresponds to the test sound output from the speaker units 17a, 17b, 17c, 17d, 17e, and 17f in order from the left.

  Here, as described above, the microphone 18 is disposed in front of the speaker unit 17 a constituting the speaker 17. That is, the speaker unit 17a is located closest to the microphone 18 that is the listening position of the user. On the other hand, the speaker unit 17c is located behind the microphone 18 in the speaker 17, and is located farthest from the listening position of the user.

  As shown in FIG. 3B, the amplitude of the waveform corresponding to the speaker unit 17a located closest to the microphone 18 among the waveforms of the received signals corresponding to the test sound from each speaker unit is maximized. Thus, the amplitude of the waveform corresponding to the speaker unit 17c located farthest from the microphone 18 is minimized. That is, it can be seen that the speaker unit corresponding to the waveform having the maximum amplitude among the waveforms included in the received signal is located closest to the microphone 18 that is the listening position of the user.

  In the sound reproducing device 1 according to the present invention, a plurality of speaker units that output sound are selected from the six speaker units 17a to 17f constituting the speaker 17. The selection of the plurality of speaker units that output sound may be, for example, a configuration in which all the speaker units 17a to 17f are selected unconditionally. Alternatively, a configuration in which a predetermined number of speaker units are selected in the order closer to the listening position is not particularly limited.

  The configuration in which a predetermined number of a plurality of speaker units are selected in the order close to the listening position will be described in more detail as follows. As described above, in the audio reproduction device 1 according to the present invention, the reception signal from the microphone 18 is converted from the analog signal to the digital signal in the ADC 14 and supplied to the amplitude detection unit 13. Then, the amplitude detector 13 detects the amplitude of the waveform included in the received signal. Here, for example, when the memory 16 stores voice output in advance by four speaker units, the amplitude detector 13 detects four waveforms in descending order of amplitude among the waveforms included in the received signal. To do. Then, the amplitude detection unit 13 outputs speaker unit detection information representing the speaker unit corresponding to the detected four waveforms to the control unit 15. Thereby, in the music reproduction apparatus 1, four speaker units are detected in the order close to the user's listening position.

  Furthermore, the control unit 15 outputs a control signal that instructs the gain adjustment unit 6 to select the four speaker units specified by the speaker detection information as speaker units that output sound. In other words, the control unit 15 outputs a control signal that instructs the gain adjustment unit 6 to set the gain of the audio signal supplied to the two speaker units not designated by the speaker detection information to zero. To do. As a result, the gain adjusting unit 6 sets the gain of the audio signal supplied to the two speaker units not specified by the speaker detection information to 0, and outputs the sound only from the four speaker units specified by the speaker detection information. Will be.

  That is, in the example shown in FIG. 3B, the amplitude detector 13 detects the speaker units 17a, 17b, 17d, and 17e as four speaker units close to the listening position. And the amplitude detection part 13 outputs the information showing the speaker units 17a, 17b, 17d, and 17e to the control part 15 as speaker unit detection information. Further, the control unit 15 sends a control signal for instructing the gain adjusting unit 6 to set the gain of the audio signal supplied to the two speaker units 17c and 17f not specified by the speaker detection information to zero. Output. Then, the gain adjusting unit 6 sets the gain of the audio signal supplied to the speaker units 17c and 17f to 0 according to the control signal from the control unit 15. Thereby, in the audio reproduction device 1 according to the present embodiment, the audio is output only from the speaker units 17a, 17b, 17d, and 17e among the speaker units 17a to 17f constituting the speaker 17.

  In the above configuration, the speaker unit closest to the user's listening position is detected based on the amplitude of the waveform included in the received signal. However, the delay amount of the received signal with respect to the test signal supplied to each speaker unit is determined. On the basis of this, it is also possible to adopt a configuration in which a plurality of speaker units are detected in the order closer to the user's listening position. This configuration will be described in more detail as follows.

  In the audio reproduction device 1 according to the present invention, the received signal from the microphone 18 is converted from an analog signal to a digital signal in the ADC 14 and then supplied to the amplitude detector 13. Further, the amplitude detection unit 13 outputs the received signal to the delay amount detection unit 12. Further, the test signal generation circuit 11 outputs a test signal which is an original signal of the test sound output from each speaker unit to the delay amount detection unit 12.

  Then, the delay amount detection unit 12 detects the delay amount of the original signal from the test signal with respect to the test sound reception signal output from each speaker unit. This delay amount becomes smaller as the distance between the speaker unit and the microphone 18 is shorter. Therefore, the speaker unit corresponding to the received signal having the smallest delay amount is located closest to the position of the microphone 18 (that is, the listening position).

  In the present embodiment, the delay amount detection unit 12 includes a test signal supplied to each speaker unit shown in FIG. 3A and a test sound microphone 18 output from each speaker unit shown in FIG. The received signal is compared with the received signal to detect the delay amount of the received signal with respect to the test signal for each speaker unit. Here, for example, when the memory 16 stores in advance the sound output by the four speaker units, the delay amount detection unit 12 displays the speaker unit detection information representing the four speaker units in order of increasing delay amount. Output to the control unit 15. Thereby, in the audio | voice reproduction apparatus 1, four speaker units are detected in the order near a user's listening position. That is, in the example shown in FIG. 3B, since the delay amounts of the speaker units 17a, 17b, 17d, and 17e are small, the delay amount detection unit 12 uses the speaker units 17a, 17b, 17d, and 17e as the speaker unit detection information. Is output to the control unit 15.

  Further, the control unit 15 sends a control signal for instructing the gain adjusting unit 6 to set the gain of the audio signal supplied to the two speaker units 17c and 17f not specified by the speaker detection information to zero. Output. Then, the gain adjusting unit 6 sets the gain of the audio signal supplied to the speaker units 17c and 17f to 0 according to the control signal from the control unit 15. Thereby, in the audio reproduction device 1 according to the present embodiment, the audio is output only from the speaker units 17a, 17b, 17d, and 17e among the speaker units 17a to 17f constituting the speaker 17.

  In addition, as a configuration for selecting a plurality of speaker units that output sound among the speaker units constituting the speaker, for example, the delay time detected by the delay amount detection unit 12 is within a predetermined time Xms, for example. There is a configuration for selecting a speaker unit. Or the structure which selects the speaker whose amplitude (namely, sound pressure level) detected in the amplitude detection part 13 is Xmv or more may be sufficient. Furthermore, as described above, the configuration may be such that all speaker units are selected unconditionally, and there is no particular limitation.

  1 and 2 are configured to output sound through two speakers, but may be configured to output sound using one speaker, or three units. The present invention can be applied to a configuration in which sound is output by the above speaker, and is not particularly limited.

  Hereinafter, control of audio output by the audio reproduction device 1 when all the speaker units are selected will be described.

(Adjustment between multiple speaker units)
As described above, audio is output from a plurality of speaker units constituting one speaker in the audio reproduction device 1 according to the present embodiment. In this case, normally, a plurality of sounds having different phases and frequency characteristics arrive at the listening position. Therefore, a plurality of sounds having different phases and frequency characteristics are synthesized at the listening position, so that the sound pressure waveform that reaches the listener's ear becomes dull and the clarity of the sound is impaired.

  Therefore, in the audio reproduction device 1 according to the present invention, the speaker is configured so that the delay and frequency characteristics of the audio output from the speaker units 17a to 17f constituting the speaker 17 based on the same audio signal are equal at the listening position. Adjust audio output between units. Below, in the audio | voice reproduction apparatus 1, the structure which adjusts the audio | voice output between said speaker units is demonstrated in detail.

  As described above, in the audio reproduction device 1, the reception signal from the microphone 18 illustrated in FIG. 3B is converted into a digital signal via the ADC 14 and supplied to the amplitude detection unit 13. Then, the amplitude detector 13 detects the amplitude of each waveform corresponding to the speaker units 17 a to 17 f included in the received signal, and outputs the detected amplitude to the controller 15.

  In the audio reproduction device 1, as described above, the reception signal from the microphone 18 is supplied to the amplitude value detection unit 13, and the amplitude detection unit 13 further supplies the reception signal to the delay amount detection unit 13. Further, the test signal generation circuit 11 outputs a test signal which is an original signal of the test sound output from each speaker unit to the delay amount detection unit 12.

  The delay amount detector 12 compares the test signal supplied to each speaker unit shown in FIG. 3A with the received signal corresponding to each speaker unit shown in FIG. The delay amount of the received signal with respect to the signal is detected. Then, the delay amount detection unit 12 outputs the delay amount of the reception signal with respect to the test signals of the speaker units 17 a to 17 f to the control unit 15.

  The control unit 15 detects the maximum delay amount among the delay amounts of the reception signals corresponding to the speaker units 17a to 17f. Then, a difference value between the detected maximum delay amount and the delay amount of each received signal is calculated and written in the memory 16. When the controller 15 outputs sound from the speaker units 17a to 17f, the phase of the sound output from the speaker units 17a to 17f based on the same sound signal is used at the listening position using the difference value. Make adjustments so that they are identical.

  For example, when the delay amounts of the received signals from the speaker units 17a to 17f shown in FIG. 3B are 0.1 ms, 0.25 ms, 0.4 ms, 0.25 ms, 0.2 ms, and 0.3 ms, respectively. The control unit 15 detects the delay amount 0.4 ms of the reception signal corresponding to the speaker unit 17c as the maximum delay amount. Then, the control unit 15 calculates a difference value between the maximum delay amount of 0.4 ms and the delay amount of the reception signal corresponding to each speaker unit, and writes it in the memory 16. In this case, the difference values corresponding to the speaker units 17a to 17f are 0.3 ms, 0.15 ms, 0 ms, 0.15 ms, 0.2 ms, and 0.1 ms, respectively. And the control part 15 supplies the control signal showing the instruction | indication which delays the timing which supplies an audio | voice signal to speaker unit 17a-f only by the said difference value to the delay circuits 4a-f corresponding to each speaker unit, respectively. Alternatively, the control unit 15 delays a control signal indicating an instruction to delay the timing of supplying the audio signal to the speaker units 17a to 17f by adding a uniform delay time to the difference value, corresponding to each speaker unit. The configuration may be such that the circuits 4a to 4f are supplied, and is not particularly limited. In this case, for example, if the uniform delay time is 0.1 ms, the control unit 15 sets the timing for supplying the audio signal to the speaker units 17a to 17f to 0.4 ms, 0.25 ms, 0.1 ms, and 0, respectively. A control signal indicating an instruction to delay by 25 ms, 0.3 ms, and 0.2 ms is supplied to the delay circuits 4a to 4f.

  Thereby, among the speaker units 17a to 17f constituting the speaker 17, all the sounds output from the plurality of speaker units have the same phase at the listening position. For this reason, the sound output from the plurality of speaker units constituting one speaker at the listening position is not synthesized with a plurality of sounds having different phases, so that the sound pressure waveform reaching the ear of the listener is not synthesized. Rounding can be reduced, and the user can listen to sound with clear sound quality.

  Further, in the audio reproduction device 1, the speaker unit is set such that the amplitude frequency characteristics at the listening position of the audio output from the speaker units 17a to 17f constituting the speaker 17 based on the same audio signal are flat (substantially constant). The audio signal supplied to 17a-f can be corrected. Hereinafter, a process for flattening the amplitude frequency characteristic in the audio reproducing apparatus 1 will be described.

  First, the sound reproducing device 1 picks up the sound output from the speaker unit 17a based on the test signal by the microphone 18 and measures the amplitude frequency characteristic at the listening position from the obtained received signal. More specifically, for example, a frequency sweep signal having a sine waveform is supplied as a test signal to the speaker unit 17a, and sound output based on the sweep signal is collected by the microphone 18, and the amplitude of the received signal obtained is obtained. Is detected by the amplitude detector 13 to obtain the frequency characteristic of the sound pressure at the listening position. Usually, the sound pressure in a certain frequency band increases or decreases depending on the characteristics of the speaker and the surrounding environment, and the amplitude frequency characteristics are not flat and include peaks and dips. The configuration for measuring the amplitude frequency characteristic may be a configuration using a test signal other than the sweep signal, and is not particularly limited.

  The amplitude detector 13 outputs the detected amplitude of the received signal to the controller 15. The control unit 15 stores the data of the amplitude frequency characteristic at the listening position of the sound output from the speaker unit 17 a in the memory 16. Further, the control unit 15 calculates a filter having an inverse characteristic of the amplitude frequency characteristic measured based on the test signal.

  When the sound is output from the speaker unit 17a based on the sound signal input from the outside, the control unit 15 applies the calculated inverse characteristic filter to the sound signal with respect to the frequency characteristic correction unit 5a. A control signal for instructing this is supplied. The frequency characteristic correction unit 5a may be configured as a multi-band equalizer (IIR filter) and may provide a reverse characteristic to the audio signal in accordance with a control signal from the control unit 15, or may be an FIR filter. The filter coefficient representing the correction characteristic (that is, the reverse characteristic) is acquired from the control unit 15 and the convolution calculation is performed on the audio signal, and is not particularly limited. Further, the frequency characteristic correction unit 5 may be configured to correct the amplitude frequency characteristic of the entire frequency band, or may be configured to correct the amplitude frequency characteristic only in the audible frequency band, and there is no particular limitation. Not.

  Then, after correcting the amplitude frequency characteristic of the sound output from the speaker unit 17a, the amplitude frequency characteristic of the sound output from the speaker units 17b to 17f is corrected by the same process.

  As a result, the rise and fall (that is, the peak and dip) of the amplitude frequency characteristic at the listening position of the sound output from the speaker units 17a to 17f is canceled, and the sound pressure characteristic that is flat with respect to the frequency (that is, the amplitude frequency characteristic) is obtained. Since the correction can be performed, the sound can be reproduced more faithfully to the original sound at the listening position.

  Further, in the audio reproduction device 1, after the amplitude frequency characteristic is corrected by the frequency characteristic correction unit 5, the gain can be adjusted by the gain adjustment unit 6. Hereinafter, gain adjustment in the gain adjusting unit 6 will be described with reference to FIGS.

  In the examples shown in FIGS. 4 to 7, three speaker units are selected as the speaker units that output sound among the speaker units 17a to 17b. 4A to 4C are diagrams showing amplitude frequency characteristics at the listening position of the sound output from each selected speaker unit. Based on the amplitude frequency characteristics shown in FIGS. 4A to 4C, the frequency characteristic correction unit 5 gives correction characteristics to the audio signal supplied to each speaker unit and flattens the amplitude frequency characteristics at the listening position. To.

  Since the amplitude frequency characteristic shown in FIG. 4A has a low output level in the high frequency region, the frequency characteristic correction unit 5 performs correction to raise the output level in the high frequency region. Further, since the output level of the amplitude frequency characteristic shown in FIG. 4B is constant in the entire frequency band, the frequency characteristic correction unit 5 does not perform correction. Further, since the frequency characteristic shown in FIG. 4C has a high output level in the middle frequency region, the frequency characteristic correction unit 5 performs correction for suppressing the output level in the middle frequency region.

  FIGS. 5A to 5C show frequency characteristics that are inverse characteristics of the amplitude frequency characteristics shown in FIGS. 4A to 4C. 5A is a diagram showing the reverse characteristics of FIG. 4A, FIG. 5B is a diagram showing the reverse characteristics of FIG. 4B, and FIG. It is a figure which shows the reverse characteristic of 4 (c). As described above, the control unit 15 calculates a filter corresponding to the inverse characteristic (that is, the frequency characteristic shown in FIG. 5) of the amplitude frequency characteristic (that is, the frequency characteristic shown in FIG. 4) measured based on the test signal. Further, the control unit 15 outputs a control signal instructing the frequency characteristic correction unit 5 to apply the calculated inverse characteristic filter to the audio signal.

  And the frequency characteristic correction | amendment part 5 is respectively shown to Fig.5 (a)-(c) with respect to each audio | voice signal supplied to each speaker unit corresponding to the amplitude frequency characteristic of Fig.4 (a)-(c). Filter processing for imparting the reverse characteristic correction characteristic shown in FIG.

  When the gain is adjusted by the gain adjusting unit 6 after the amplitude frequency characteristic is corrected by the frequency characteristic correcting unit 5, the test signal is subjected to filter processing having an inverse characteristic and output from the speaker unit. Then, the sound output from the speaker unit is collected by the microphone 18 at the listening position, and the amplitude frequency characteristic is calculated based on the amplitude of the obtained reception signal.

  6A to 6C are diagrams showing the amplitude frequency characteristics at the listening position of the sound after the correction by the frequency characteristic correction unit 5. 6A is a diagram showing the amplitude frequency characteristic after correction of FIG. 4A, FIG. 6B is a diagram showing the amplitude frequency characteristic after correction of FIG. 4B, FIG. 6C is a diagram illustrating the amplitude frequency characteristic after the correction in FIG. As shown in FIGS. 6A to 6C, the amplitude frequency characteristics at the listening position of the sound corrected by the frequency characteristic correcting unit 5 are all flat characteristics.

  Here, the control unit 15 determines whether or not the DAC 8 can convert the sound output level after correction shown in FIGS. 6A to 6C into an analog signal. That is, in the DAC 8, the digital value representing the audio signal from the frequency characteristic correcting unit 5 is converted into an analog signal. However, the digital value of the audio signal subjected to the filter processing in the frequency characteristic correcting unit 5 is converted in the DAC 8. It is determined whether or not the maximum value that can be converted into an analog signal is exceeded.

  As a result of the above determination, the gain adjusting unit 6 is set so as to reduce the gain for the path of the audio signal that exceeds the range that can be handled by the DAC 8 and does not have a sufficient dynamic range. For example, when the audio signal corresponding to the amplitude frequency characteristic of FIG. 6A exceeds the range that can be handled by the DAC 8, the control unit 15 determines that the digital value of the audio signal corresponding to the amplitude frequency characteristic of FIG. A gain that is within a range that can be handled by the DAC 8 is calculated. And the control part 15 outputs the control signal showing the instruction | indication which sets the calculated gain with respect to the gain adjustment part 6 of the speaker unit to which the audio | voice signal corresponding to the amplitude frequency characteristic of Fig.6 (a) is supplied. .

  Thereby, the gain adjustment unit 6 can reduce the size of the audio signal supplied to the speaker unit to a size that can be converted into an analog signal by the DAC 8, and can prevent digital clipping. It is possible to suppress noise in audio reproduction.

  7A to 7C are diagrams illustrating the amplitude frequency characteristics of the output from the gain adjusting unit 6. FIGS. 7A to 7C are diagrams illustrating the amplitude frequency characteristics of the output from the gain adjustment unit 6 of the audio signal corresponding to the amplitude frequency characteristics of FIGS. 6A to 6C, respectively. Since the output level of the sound after the frequency characteristic correction shown in FIG. 6A exceeds a value that can be converted by the DAC 8, the gain adjustment unit 6 adjusts the gain based on the control signal from the control unit 15. As a result, since the output level is reduced as shown in FIG. 7A, digital clipping can be prevented. On the other hand, the output level of the sound after the frequency characteristic correction shown in FIGS. 6B and 6C is within a range that can be converted by the DAC 8, and the gain adjustment unit 6 does not adjust the gain. Accordingly, the amplitude frequency characteristics shown in FIGS. 7B and 7C are the same as the amplitude frequency characteristics shown in FIGS. 6B and 6C.

(Adjustment between two speakers)
As described above, the sound reproducing device 1 according to the present invention has the same phase and frequency characteristics at the listening position of all sounds output from the plurality of speaker units in the speaker including the plurality of speaker units. The size and delay of the audio signal supplied to each speaker unit are controlled. Furthermore, the audio reproduction device 1 according to the present invention controls audio output between speakers in an audio reproduction system including a plurality of speakers including a plurality of speaker units.

  Below, the structure which adjusts the audio | voice output between the speakers 17 and 17 'which comprise the stereo audio | voice reproduction system shown in FIG. 2 is demonstrated.

  FIG. 8 is a diagram showing the positional relationship between the speakers 17 and 17 ′ and the listener constituting the stereo reproduction system shown in FIG. 2. As shown in FIG. 8, the installation position (that is, the listening position) of the microphone 18 is the front of the speaker 17 and is closer to the speaker 17 than the speaker 17 ′. A microphone 18 is installed at the listener's position shown in FIG. 8 as shown in FIG.

  Further, as shown in FIG. 2, the speakers 17 and 17 'are hexahedral speakers each including six speaker units. Then, when adjusting the sound output between the speakers, the sound reproducing device 1 according to the present invention outputs a test sound from each speaker based on the test signal and collects the received signal by the microphone 18 as a received signal. Use to adjust audio output between speakers.

  At this time, the audio reproduction device 1 selects a plurality of speaker units that output sound for each of the speakers 17 and 17 ′ by the above-described method, and outputs all of the output from the selected plurality of speaker units for each speaker. The delay amount of the test signal supplied to each speaker unit is controlled so that the sound phase and frequency characteristic of the sound are the same, and the frequency characteristic is corrected and the gain is adjusted. That is, when the audio output between the speakers is adjusted, the audio reproducing apparatus 1 previously has the same phase and frequency characteristics of all the audios output from the plurality of speaker units selected in each speaker. In addition, based on the control signal from the control unit 15, the delay circuit 4, the gain adjustment unit 6, and the frequency characteristic correction unit 5 set the gain and delay amount of the audio signal supplied to each speaker unit, or the correction characteristics. Is granted. Then, with the above settings made, test audio is output from each speaker based on the test signal, and the audio output between the speakers is adjusted using the received signal obtained by collecting the sound with the microphone 18 To do.

  FIG. 9 is a diagram for explaining control of audio output between two speakers. FIG. 9A is a diagram illustrating a time waveform of a test signal supplied to the speakers 17 and 17 ′, and FIG. It is a figure which shows the time waveform of the received signal in the microphone 18 of the test sound output from the speakers 17 and 17 '.

  The horizontal axes of FIGS. 9A and 9B indicate time. As shown in FIG. 9A, each test signal supplied to the speakers 17 and 17 ′ is one cycle of a sine wave, and the waveform itself is the same, but the test supplied to the speaker 17 ′. The phase of the signal is delayed compared to the test signal supplied to the speaker 17. That is, the timing at which one cycle of the sine wave included in the test signal is supplied to the speaker 17 ′ is delayed from the timing at which the speaker 17 is supplied. In the audio signal reproduction device 1, the audio signal supplied to each speaker shown in FIG. 9 (a) is a gain or delay time corresponding to the speaker unit with respect to a plurality of speaker units that output the audio of each speaker. Are adjusted and supplied. That is, in the audio signal reproduction device 1, the audio signal is supplied to each of the plurality of speaker units that output the audio of each speaker, based on the audio signal supplied to each speaker shown in FIG. 9A. . In the present embodiment, in the speakers 17 and 17 ', all speaker units are selected as speaker units that output sound. That is, the audio signal is supplied to the speaker units 17a to 17f and the speaker units 17'a to f. Similarly to the description of the test signal in FIG. 3, the memory 16 stores test signal data representing the test signal.

  When the test sound is reproduced, the control unit 15 reads the test signal data from the memory 16 and supplies the test signal data to the test signal generation circuit 11. Then, the test signal generation circuit 11 generates a test signal based on the supplied test signal data.

  In this case, the control unit 15 supplies a control signal that instructs the selection circuit 7 to output a test signal. As a result, the selection circuit 7 outputs the test signal shown in FIG. 9A, and the audio signal is sequentially supplied to the delay circuit 4, the frequency characteristic correction unit 5, the gain adjustment unit 6, the DAC 8, and the amplifier 9. . Further, the control unit 15 supplies control signals to the delay circuit 4, the frequency characteristic correction unit 5, and the gain adjustment unit 6 to control the gain and delay time according to the speaker units 17a to 17f. The speaker units 17a to 17f are supplied with audio signals whose gain and delay time are adjusted via the DAC 8 and the amplifier 9, respectively. Then, the speaker units 17a to 17f output a test sound based on the sound signal whose gain and delay time are adjusted.

  Although only the speaker 17 is shown in FIG. 1, the same test signal is supplied to the speaker 17 'by the same configuration. Then, from the speaker 17 ′, a test sound is output based on the test sound shown in FIG.

  The microphone 18 collects the test sound output from the speakers 17 and 17 ′ and converts it into a received signal shown in FIG. 9B. The received signal shown in FIG. 9B shows an example in which the microphone 18 is arranged closer to the speaker 17 than the speaker 17 ′ as shown in FIG. 2. As shown in FIG. 9B, the received signal includes two waveforms of one sine wave having different amplitudes, and corresponds to the test sound output from the speakers 17 and 17 ', respectively.

  The test sound is output from the speaker units 17a to 17f and the speaker units 17'a to f, respectively, but the phase of the test sound output from each speaker unit is the same for each speaker at the listening position. The amplitude varies from speaker unit to speaker unit. In FIG. 9B, only one received signal is shown for each speaker, but the amplitude of the received signal shown in FIG. 9B is from the speaker units 17a to 17f constituting each speaker. The sum of the amplitudes of the received audio signals is shown.

  In the following description, the sound output from the speaker 17 refers to the sound output from the speaker units 17a to 17f, and the sound output from the speaker 17 'refers to the output from the speaker units 17'a to f. Refers to the voice that is played.

  As described above, the microphone 18 is disposed closer to the speaker 17 than the speaker 17 '. For this reason, in the example shown in FIG. 9B, the sum of the amplitudes of the received signals corresponding to the test sound output from the speaker 17 is the sum of the amplitudes of the received signals corresponding to the test sound output from the speaker 17 ′. Bigger than Further, the delay amount of the reception signal with respect to the test signal of the speaker 17 is smaller than the delay amount of the reception signal with respect to the test signal of the speaker 17 ′.

  For this reason, based on the same audio signal, the audio output from the two speakers differs in phase and amplitude sum at the listening position. Therefore, at the listening position, voices having different phases and amplitudes are synthesized, so that the waveform of the sound reaching the user's ears is distorted and the clarity is lost.

  Therefore, in the sound reproducing device 1 according to the present invention, the sound waveform output from the speaker 17 and the speaker 17 ′ based on the same sound signal is set so that the total output is equal at the listening position. Adjust the audio output between. Below, the structure which adjusts the audio | voice output between speakers in the audio | voice reproduction apparatus 1 is demonstrated in detail.

  The microphone 18 collects the test sound output from the speakers 17 and 17 ′ and converts it into a received signal shown in FIG. As described above, in FIG. 9B, the amplitude of the reception signal from the speaker 17 is the sum of the amplitudes of the reception signals from the speaker units 17a to 17f, and the amplitude of the reception signal from the speaker 17 ′ is This is the sum of the amplitudes of the received signals from the speaker units 17′a to f.

  Further, in the audio reproduction device 1, the reception signal from the microphone 18 is converted from an analog signal to a digital signal by the ADC 14, and then supplied to the amplitude value detection unit 13. The amplitude value detection unit 13 then sums the amplitudes of the received signals corresponding to the test sound output from the speaker 17 (referred to as the sum of the amplitudes of the received signals from the speaker 17) and the test output from the speaker 17 ′. The sum of the amplitudes of the received signals corresponding to the sound (referred to as the sum of the amplitudes of the received signals from the speaker 17 ′) is detected and output to the control unit 15.

  The control unit 15 calculates the ratio between the sum of the amplitudes of the reception signals from the speakers 17 and the sum of the amplitudes of the reception signals from the speakers 17 ′ and writes them in the memory 16. When the control unit 15 outputs sound from the speakers 17 and 17 ′, the amplitude of the waveform of the sound output from the speakers 17 and 17 ′ based on the same sound signal at the listening position using the above ratio. Make adjustments so that the sum of

  For example, when the sum of the amplitudes of the reception signals from the speaker 17 shown in FIG. 9B is four times the sum of the amplitudes of the reception signals from the speaker 17 ′, the control unit 15 sets the speaker 17 (that is, the speaker). The gain adjuster 6a so that the level value of the audio signal supplied to the units 17a to 17f is 1/4 of the level value of the audio signal supplied to the speaker 17 '(ie, the speaker units 17'a to f). Control ~ f. More specifically, when audio signals having the same amplitude are supplied as the Lch signal and the Rch signal, the control unit 15 applies gains to the gain adjustment units 6a to 6f that adjust the gain of the Lch signal, respectively. Is supplied to a control signal representing an instruction to set the current gain to ¼ of the current gain, and the gain is set to 1 (that is, set) for a gain adjusting unit (not shown) that adjusts the gain of the Rch signal. A control signal is provided to represent the instruction). Alternatively, the control unit 15 controls the gain adjusting units 6a to 6f so that the level value of the audio signal supplied to the speaker 17 ′ is four times the level value of the audio signal supplied to the speaker 17. There is no particular limitation.

  Thereby, the sum of the amplitudes of the sounds output from the speakers 17 and 17 ′ are equal at the listening position. For this reason, since voices having different sums of amplitudes are not synthesized at the listening position, it is possible to reduce the rounding of the sound pressure waveform reaching the listener's ear, and the user can clearly hear the sound quality. Will be able to listen.

  In the audio reproduction device 1, the reception signal from the microphone 18 is supplied to the amplitude value detection unit 13 as described above, and the amplitude value detection unit 13 further supplies the reception signal to the delay amount detection unit 12. . Further, the test signal generation circuit 11 outputs a test signal which is an original signal of the test sound output from each speaker unit to the delay amount detection unit 12.

  The delay amount detection unit 12 compares the test signal supplied to each speaker shown in FIG. 9A with the received signal in the microphone 18 of the test sound output from each speaker shown in FIG. The delay amount of the received signal with respect to the test signal is detected for each speaker. The delay amount detection unit 12 then receives the delay amount of the received signal with respect to the test signal of the speaker 17 (referred to as the delay amount of the received signal from the speaker 17) and the delay amount of the received signal with respect to the test signal of the speaker 17 ′ (speaker 17). (Referred to as a delay amount of the received signal from “)” to the control unit 15.

  The control unit 15 calculates a difference value between the delay amount of the reception signal from the speaker 17 and the delay amount of the reception signal from the speaker 17 ′ and writes it in the memory 16. When the sound is output from the speakers 17 and 17 ′, the control unit 15 uses the difference value to determine the phase of the sound output from the speakers 17 and 17 ′ based on the same sound signal at the listening position. Make adjustments so that they are identical.

  For example, when the delay amount of the reception signal from the speaker 17 shown in FIG. 9B is smaller by 0.1 ms than the delay amount of the reception signal from the speaker 17 ′, the control unit 15 causes the speaker 17 ′ (that is, The delay circuits 4a to 4f are provided so that the audio signal is supplied to the speaker 17 (that is, the speaker units 17a to 17f) with a delay of 0.1 ms with respect to the timing of supplying the audio signal to the speaker units 17'a to f). Control. More specifically, when an audio signal having the same phase is supplied as the Lch signal and the Rch signal, the control unit 15 applies the current delay to the delay circuits 4a to 4f that adjust the delay of the Lch signal, respectively. For a delay circuit (not shown) for supplying a control signal indicating an instruction to supply the Lch signal with a delay of 0.1 ms from the time, the Rch signal is adjusted from the current delay time. A control signal representing an instruction not to delay is supplied. Alternatively, a control signal representing an instruction to delay the Lch signal supplied to the speaker units 17a to 17f by 0.2 ms from the current delay time is supplied to the delay circuits 4a to 4f, respectively, and the delay of the Rch signal is reduced. Even if it is the structure which supplies the control signal showing the instruction | indication which delays the Rch signal supplied to speaker unit 17'a-f further 0.1 ms from the present delay time with respect to the delay circuit (not shown) to adjust. Well, there is no particular limitation.

  Thereby, the phases of the sounds output from the speakers 17 and 17 'are equal at the listening position. For this reason, since the sound with different phases is not synthesized at the listening position, the rounding of the sound pressure waveform reaching the listener's ear can be reduced, and the user listens to the sound with clear sound quality. Will be able to.

  In the present embodiment, the sound output between the speakers is adjusted for each speaker unit in the delay circuits 4a to f as in the case of adjusting the sound output between the speaker units for each speaker. The delay adjusting unit 6a-f is configured to change the size of the audio signal for each speaker unit, but means for delaying the supply of the audio signal for each speaker unit and changing the size of the audio signal for each speaker unit May be provided separately, and is not particularly limited.

  As described above, in the audio reproducing device 1, the frequency characteristics are adjusted so that the amplitude frequency characteristics at the listening positions of the sounds output from all the speaker units constituting the speakers are flat for each speaker. Yes. That is, the amplitude frequency characteristic at the listening position of the sound output from the speaker 17 and the amplitude frequency characteristic at the listening position of the sound output from the speaker 17 ′ are both substantially constant.

  In the present embodiment, the configuration for controlling the audio output by the two hexahedral speakers has been described, but the number of speakers controlled by the audio reproducing device 1 according to the present invention is not limited to two. For example, the sound reproducing device 1 may be configured to control sound output from six hexahedral speakers by a method similar to that used to control sound output from two hexahedral speakers.

  FIG. 10 is a diagram showing a state in which sound is reproduced by six hexahedral speakers, and (a) is a diagram showing that a plurality of speaker units are selected in one speaker. ) Is a diagram showing that sound is output from a plurality of speaker units in each of the six speakers.

  In the configuration shown in FIG. 10, each of the left channel (Lch), center channel (Cch), right channel (Rch), right surround channel (RSch), subwoofer channel (SW), and left surround channel (LSch) audio. A speaker for outputting a signal is prepared.

  Even when sound is output from six hexahedral speakers, the sound reproducing device 1 uses the sound of the speaker units constituting the hexahedral speaker for each hexahedral speaker, as in the case of outputting sound from two hexahedral speakers. Are selected.

  In the example shown in FIG. 10A, in the hexahedral speaker that outputs the Lch audio signal surrounded by the broken line, the speaker unit that outputs the audio represented by the arrow is selected as the speaker that outputs the audio. Is shown.

  Then, the audio reproduction device 1 supplies each speaker unit with the same phase and frequency characteristics of the sound output from each speaker unit of the hexahedral speaker that outputs the Lch audio signal at the listening position. The delay amount of the audio signal is adjusted to give a correction characteristic.

  Furthermore, the audio reproduction device 1 sequentially selects a plurality of speaker units that output audio for each hexahedral speaker that outputs Cch, Rch, RSch, SW, and LSch audio signals.

  Accordingly, as shown in FIG. 10B, in each of the six speakers, sound is output from a plurality of speaker units among the six speaker units constituting the speaker.

  Similarly, for each hexahedral speaker that outputs Cch, Rch, RSch, SW, and LSch audio signals, the audio reproduction device 1 also applies the phase and frequency of audio output from a plurality of speaker units for each speaker. The delay amount of the audio signal supplied to each speaker unit is adjusted so that the characteristics are all the same at the listening position, and a correction characteristic is given.

  Furthermore, the audio reproduction device 1 adjusts the audio output between the speakers for the six hexahedral speakers using the test audio (that is, the test signal). That is, the sound reproducing device 1 uses the same method as that for controlling the sound output of the two hexahedral speakers, at the user's listening position, for the sound waveform output from each hexahedral speaker, The sound output from the six hexahedral speakers is adjusted so that the sound pressure), the delay amount from the original signal (that is, the phase difference), and the frequency characteristics are the same. For example, the sum of the amplitude at the listening position of the test sound output from six hexahedral speakers is calculated, and the magnitude of the sound signal supplied to each speaker (ie, speaker unit) is changed in accordance with the sum of the amplitudes. By adjusting, the amplitude of the sound from each speaker is adjusted. Also, for example, the supply of audio signals to each speaker (ie, speaker unit) is delayed in accordance with the maximum delay time among the delay times at the listening position of the test sound output from six hexahedral speakers. Thus, the phase of the sound from each speaker at the listening position is adjusted.

  Further, the sound reproducing device 1 according to the present invention is not limited to the configuration for controlling the hexahedral speaker, and can control various speakers including a plurality of speaker units. There is no limitation.

  The configuration of the present invention can also be expressed as follows.

  Further, in the configuration of the present invention, a plurality of speaker units with different sound emission directions are incorporated in one housing, and each speaker unit is driven independently, and sound pressure and frequency characteristics are controlled independently. As a result, the optimum sound quality environment for the viewing position is realized.

  In the configuration of the present invention, each speaker unit outputs a test signal individually and obtains the amplitude of the signal detected by the sound collecting microphone placed at the viewing position, so that which speaker unit is the viewer It detects whether it is facing the direction.

  In the configuration of the present invention, the amplitude, phase, and frequency characteristics of a signal supplied to each speaker unit are determined from the positional relationship between the speaker unit and the viewer obtained by the above method.

  In addition, in the configuration of the present invention, when there are two or more “casings incorporating a plurality of speaker units” adjusted by the above method, a test signal is added again to watch the volume balance and delay between the housings. Adjust for optimal position.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  Finally, each block included in the audio reproduction device, in particular, the delay amount detection unit 12, the amplitude detection unit 13, and the control unit 15 may be configured by hardware logic or using a CPU as follows. It may be realized by software.

  That is, the sound reproduction device includes a CPU (central processing unit) that executes instructions of a control program that realizes each function, a ROM (read only memory) that stores the program, a RAM (random access memory) that expands the program, A storage device (recording medium) such as a memory for storing the program and various data is provided. An object of the present invention is to provide a recording medium in which a program code (execution format program, intermediate code program, source program) of a control program for a sound reproduction device, which is software that realizes the functions described above, is recorded so as to be readable by a computer. This can also be achieved by supplying the sound reproduction apparatus and reading and executing the program code recorded on the recording medium by the computer (or CPU or MPU).

  Examples of the recording medium include a tape system such as a magnetic tape and a cassette tape, a magnetic disk such as a floppy (registered trademark) disk / hard disk, and an optical disk such as a CD-ROM / MO / MD / DVD / CD-R. Card system such as IC card, IC card (including memory card) / optical card, or semiconductor memory system such as mask ROM / EPROM / EEPROM / flash ROM.

  Further, the audio reproduction device may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication. A net or the like is available. Further, the transmission medium constituting the communication network is not particularly limited. For example, even in the case of wired such as IEEE 1394, USB, power line carrier, cable TV line, telephone line, ADSL line, etc., infrared rays such as IrDA and remote control, Bluetooth ( (Registered trademark), 802.11 wireless, HDR, mobile phone network, satellite line, terrestrial digital network, and the like can also be used. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

  The audio reproduction device according to the present invention can be applied to an audio reproduction device that outputs audio using a speaker constituted by a plurality of speaker units, and is particularly suitable for an audio reproduction device that outputs audio using a polyhedral speaker.

It is a block diagram which shows the structure of the audio | voice reproduction apparatus which concerns on this invention. It is a figure which shows the structure of the audio | voice reproduction | regeneration system based on this invention. It is a figure for demonstrating selection of the speaker unit in this Embodiment, (a) is a figure which shows the time waveform of the test signal supplied to each speaker unit which comprises the speaker 17, (b) is a microphone It is a figure which shows the time waveform of the received signal in. (A)-(c) is a figure which shows the amplitude frequency characteristic in the listening position of the audio | voice output from each selected speaker unit. (A) to (c) are frequency characteristics opposite to the amplitude frequency characteristics shown in FIG. (A)-(c) is a figure which shows the amplitude frequency characteristic in the listening position of the audio | voice after correction | amendment by the frequency characteristic correction | amendment part. (A)-(c) is a figure which shows the amplitude frequency characteristic of the output from a gain adjustment part. It is a figure which shows the positional relationship of two speakers and listeners which comprise the stereo reproduction | regeneration system shown in FIG. It is a figure for demonstrating control of the audio | voice output between the two speakers in this Embodiment, (a) is a figure which shows the time waveform of the test signal supplied to two speakers, (b) FIG. 4 is a diagram illustrating a time waveform of a reception signal in a microphone of a test sound output from two speakers. It is a figure which shows a mode in the case of reproducing | regenerating an audio | voice by six hexahedral speakers, (a) is a figure which shows that the several speaker unit is selected in one speaker, (b) It is a figure which shows that the audio | voice is output from the several speaker unit in each of six speakers. It is a figure which shows the image of the waveform of the original sound reproduced | regenerated in a polyhedral speaker, the waveform in the listening position of the sound output from each speaker unit, and those synthetic waveforms, (a) is a figure which shows the image of the waveform of an original sound. (B) is a figure which shows the image of the waveform in the listening position of the sound output from the front speaker unit, (c) is the figure which shows the image of the waveform in the listening position of the sound output from the side speaker unit. (D) is a figure which shows the image of the waveform in the listening position of the sound output from the speaker unit of a back surface, (e) shows the image of the waveform which synthesize | combined the waveform of (b)-(d). FIG.

Explanation of symbols

1 Audio playback device 2 Input terminal 3 ADC
4 delay circuit (first delay means, second delay means)
5 Frequency characteristic correction unit (Frequency characteristic correction means)
6 Gain adjustment section (selection means, first amplitude adjustment means, second amplitude adjustment means)
7 Selection circuit 8 DAC
9 Amplifier 11 Test Signal Generation Circuit 12 Delay Amount Detection Unit 13 Amplitude Detection Unit 14 ADC
DESCRIPTION OF SYMBOLS 15 Control part 16 Memory 17 Speaker 17 'Speaker 17a-f Speaker unit 17'a-f Speaker unit 18 Microphone 100 Sound reproduction system

Claims (14)

An audio reproduction device that outputs audio through a plurality of speakers each including a plurality of speaker units,
Selecting means for selecting a plurality of speaker units for outputting sound from the plurality of speaker units for each of the speakers;
For each speaker, delay the supply of audio signals to each speaker unit so that the phases of all the sounds output from the plurality of speaker units selected by the selection means are equal at the listening position of the user. An audio reproducing apparatus comprising first delay means for causing the sound to be reproduced.   Supply of audio signals to the respective speaker units so that the phases at the listening position of the sound output from the plurality of speaker units selected for each of the speakers by the selection means are all equal between the plurality of speakers. The audio reproduction apparatus according to claim 1, further comprising second delay means for delaying the delay time.   The first amplitude adjusting means for individually changing the magnitude of the audio signal supplied to the plurality of speaker units selected by the selecting means for each speaker. Or the audio | voice reproduction apparatus of 2.   The sound output from the plurality of speaker units selected for each of the speakers by the selection means is supplied to each speaker unit so that the sum of the amplitudes at the listening position is equal between the plurality of speakers. 3. The sound reproducing apparatus according to claim 1, further comprising second amplitude adjusting means for changing the magnitude of the sound signal.   For each of the speakers, the amplitude frequency characteristics of all sounds output from the plurality of speaker units selected by the selection means are substantially constant at least in the audible frequency band at the user's listening position. 5. The sound reproducing apparatus according to claim 1, further comprising frequency characteristic correcting means for imparting correction characteristics to the sound signal supplied to the speaker unit. The selection means is:
6. The sound reproducing apparatus according to claim 1, wherein a predetermined number of speaker units are selected for each of the speakers in the order close to the listening position. An audio playback device that outputs audio through a speaker composed of a plurality of speaker units,
Selecting means for selecting a plurality of speaker units for outputting sound from the plurality of speaker units;
Delay means for delaying the supply of audio signals to the respective speaker units so that the phases of all the sounds output from the plurality of speaker units selected by the selection means are equal at the listening position of the user; An audio reproducing apparatus characterized by comprising:   8. The audio reproducing apparatus according to claim 7, further comprising amplitude adjusting means for individually changing the magnitudes of the audio signals supplied to the plurality of speaker units selected by the selecting means.   The amplitude frequency characteristics of all sounds output from the plurality of speaker units selected by the selection means are supplied to the respective speaker units so as to be substantially constant at least in the audible frequency band at the user's listening position. 9. The audio reproducing apparatus according to claim 7, further comprising frequency characteristic correcting means for imparting correction characteristics to the audio signal. The audio reproduction device according to any one of claims 1 to 9,
A sound reproduction system comprising: a microphone that collects sound output from the sound reproduction device; converts the collected sound into an electrical reception signal; and outputs the signal to the sound reproduction device. . An audio reproduction method for outputting audio via a plurality of speakers each comprising a plurality of speaker units,
For each of the speakers, a selection step of selecting a plurality of speaker units that output sound from the plurality of speaker units;
For each speaker, delay the supply of audio signals to each speaker unit so that the phases of all the sounds output from the plurality of speaker units selected by the selection means are equal at the listening position of the user. A sound reproduction method characterized by including a first delay step. An audio reproduction method for outputting audio through a speaker composed of a plurality of speaker units,
A selection step of selecting a plurality of speaker units for outputting sound from the plurality of speaker units;
A delay step for delaying the supply of audio signals to the respective speaker units so that the phases of all the audios output from the plurality of speaker units selected in the selection step are equal at the listening position of the user. An audio reproduction method comprising:   A control program for operating the sound reproduction device according to any one of claims 1 to 9, wherein the control program causes a computer to function as each of the above means.   A computer-readable recording medium in which the control program according to claim 13 is recorded.

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