JP2011004261A - Av amplifier apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an AV amplifier apparatus in which a sense of localization or a sense of distance is clear and a sense of being surrounded with surround sound can be enriched when outputting multi-channel sound signals to a plurality of speakers disposed according to a direct surround system and playing back sound in accordance with a diffuse surround system.SOLUTION: The AV amplifier apparatus 1 uses both pan-based localization processing and virtual processing for imparting frequency characteristics of sound heard from a localization position based on a head transfer function, in order to output multi-channel sound signals to a plurality of speakers disposed in front of a listening position and at the back of the listening position and localize the sound source at both sides of the listening position. Furthermore, it is set by both the processing to localize the sound source at the same position for every channel. Thus, two kinds of localization processing are performed to make clear a sense of localization or a sense of distance.

Description

  The present invention relates to an AV amplifier apparatus that outputs multi-channel audio signals to a plurality of speakers.

  In general, a direct surround system is widely used in ordinary households as a speaker system for reproducing surround sound. On the other hand, in movie theaters, a diffuse surround system is employed (see Non-Patent Document 1).

  FIG. 1 is a diagram showing the arrangement of speakers in the direct surround system and the diffuse surround system. As shown in FIG. 1A, the direct surround system is an installation method in which a surround speaker is arranged toward a listening point (listening position 90 of the listener U). This direct surround system has been proposed from a 5.1 channel system in which speakers are arranged in a plane to a 11.1 channel system (not shown) in which speakers are arranged so as to surround the viewing position in three dimensions. Yes. This method is suitable for listening to music because the sound image becomes clear.

  On the other hand, as shown in FIG. 1B, the diffuse surround system is an arrangement method in which a wide cover area is provided for surround speakers (rear channel speakers). In this system, an Lds1 channel speaker 18 and an Rds1 channel speaker 20 are installed on both sides of the listener, and an Lds2 channel speaker 19 and an Rds2 channel speaker 21 are arranged behind the listener. In addition, special speakers such as a tripole speaker are used as the Lds1 channel speaker 18 and the Rds1 channel speaker 20 installed on both sides of the listener. As a result, the surround area (areas 22S and 23S indicated by dotted lines in FIG. 1B) is widened to increase the sense of surround sound. This method is suitable for watching a movie in which the effect by surround sound is effective.

  As described above, since the direct surround system is widespread in ordinary households, when a viewer watches a movie, audio is reproduced by the direct surround method or, as shown in FIG. The sound was reproduced by simulating a diffuse surround system suitable for the above.

  FIG. 2 is a diagram for explaining a conventional method for simulating the diffuse surround system by the direct surround system. Conventionally, as shown in FIG. 2, the sound signal is distributed to adjacent speakers, and the sound source is localized by pan. In other words, the audio signal of the Lds1 (Rds1) channel is distributed to the L (R) channel speaker 11 (13) and the SL (SR) channel speaker 14 (15), and the Lds1 ( The sound source 18P (20P) of the Rds1) channel was localized. The audio signal of the Lds2 (Rds2) channel was distributed to the SL channel speaker 14 and the SR channel speaker 15, and the sound source 19P (21P) of the Lds2 (Rds2) channel was localized at the left rear (right rear) of the listener. .

Monitor environment for multi-channel software production, [online] [searched on March 19, 2009], Internet <URL: http://surround.jp/past/jas_journal/050207/01.pdf>

  As is well known, a person determines the localization of a sound source based on sound heard from both ears. However, in the method shown in FIG. 2, the sound to be heard from the side is distributed to speakers arranged in front of and behind the listener, and the sound source 18P of the Lds1 channel and the sound source 20P of the Rds1 channel are localized in both directions of the listener U. Let For this reason, the sound pressure difference between the speakers arranged before and after the listener is weak as a clue to feel the localization, and the listener has difficulty in finding the localization of both channels. Therefore, when the sound of content such as a movie is reproduced by the conventional simulation method, there is a problem that the sense of localization and the sense of distance of the sound source are unclear with respect to the intended sound source position.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an AV amplifier apparatus that performs a process of emitting sound from speakers arranged in front of and behind a listening position and localizing a sound source to the side of the listening position.

  The AV amplifier apparatus according to the present invention performs sound signal processing using two methods in combination, outputs sound signals to a plurality of speakers arranged on the front side and the back side of the listener's listening position, Clarify feeling and distance. As a first method, the distributing means distributes the audio signal of the same channel to the speakers arranged on the front side and the rear side of the listening position at a ratio corresponding to the position where each channel should be localized. That is, the sound source is localized at the position where each channel should be localized by pan. As a second method, the characteristic imparting means imparts the frequency characteristic of the sound propagating from one position of the channel to one ear of the listener to the sound signal of each channel. Further, when the sound based on the sound signal output from the characteristic imparting means is emitted from the speaker toward the listener by the crosstalk correcting means, a sound signal that cancels the sound heard by the other ear is generated and output. That is, the sound source is virtually localized at the position to be localized in the channel by virtual processing using the head-related transfer function. For example, when the sound source is localized by panning in both directions of the listening position, the listener is weak as a clue to sense the localization only by the difference in sound pressure between the speakers arranged at the front and back, and the localization of both channels is difficult to sense. For this reason, the panning alone is unclear in the sound source localization and distance. However, it is possible to make the listener strongly feel the localization of the sound source by emitting from the speaker the sound that is given the characteristic of being heard from the position where the sound source is localized by panning using virtual processing. Therefore, the sense of localization and the sense of distance of the sound source become clear, and the surround feeling of the surround sound can be enriched.

  Further, the AV amplifier device of the present invention is a reflected sound generating means, based on the reflected sound parameter that reproduces the reflected sound of the sound emitted by a plurality of speakers arranged in a diffuse surround system, and on the front side of the listening position and A sound signal of reflected sound to be output to a plurality of speakers arranged on the rear side by the direct surround method is generated. In the diffuse surround system, in order to widen the surround area and increase the surround sound, the tripole speakers are arranged on both sides of the viewing position, and multiple reflected sounds are reflected on the walls of the room. . In the present invention, the sound actually reproduced by the diffuse surround system is collected in advance, and the reflected sound parameter is created from the collected data. Then, the reflected sound reproduced based on the reflected sound parameter is emitted from a plurality of speakers. This makes it possible to reproduce the same surround area that is actually played in the diffuse surround system, so that the surround sound is further enriched even though multiple speakers are arranged in the direct surround system. it can.

  In the present invention, the crosstalk correcting means outputs an audio signal to a presence speaker installed on the upper front side of the viewing position. Since the crosstalk correcting means outputs the audio signal to the presence speaker to which no other audio signal is input, it is possible to emit an audio with a good S / N ratio. In addition, from the two front speakers installed in front of the listener, the rear channel audio signal is given a characteristic that sounds can be heard from the rear side of the listener based on the head-related transfer function, and a crosstalk cancellation process is performed. When an audio signal is output, a large dip occurs in the high range. However, it is known that as the elevation angle from the listener's listening position to the presence speaker increases, the frequency at which the dip is generated gradually increases, and the dip is improved if the elevation angle is set to be large. Therefore, even if the sound whose crosstalk correction means has been subjected to the crosstalk canceling process is emitted to a presence speaker to which no other audio signal is input, the sound source is virtually localized on the rear side without causing deterioration in sound quality. be able to.

  According to the present invention, the sound source is localized at the position where each channel is to be localized by Pan, and the sound propagates from the position where the channel is localized to one ear of the listener based on the head-related transfer function. The sound source is virtually localized at the position to be localized in the channel by virtual processing for providing the frequency characteristics of the channel. Accordingly, the localization feeling can be enhanced by panning and virtual processing, and further by adding a reflected sound, so that the localization feeling and distance feeling of the sound source can be clarified.

It is a figure which shows arrangement | positioning of the speaker by a direct surround system and a diffuse surround system. It is a figure for demonstrating the conventional method of simulating a diffuse surround system by a direct surround system. 1 is a block diagram showing a schematic configuration of an AV amplifier apparatus according to a first embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of a signal processing unit of the AV amplifier device according to the first embodiment of the present invention. It is a block diagram which shows schematic structure of the AV amplifier apparatus which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the detailed structure of the signal processing part of the AV amplifier apparatus which concerns on 2nd Embodiment of this invention.

  The AV amplifier apparatus according to the embodiment of the present invention has a localization feeling based on panning and a head-related transfer function in order to localize a sound source in both directions where it is difficult for the listener to feel the localization of the sound source. The two processes, the virtual process to be given, are used together. Specifically, when outputting sound signals of a plurality of channels to a plurality of speakers arranged in the direct surround system on the front side and the rear side of the listening position and reproducing the sound in the diffuse surround system, By using the virtual processing to localize the sound source at the same position, the sense of localization and the sense of distance of the sound source are clarified and the surround sound is surrounded.

[First Embodiment]
Details of the AV amplifier device will be described below. FIG. 3 is a block diagram showing a schematic configuration of the AV amplifier apparatus according to the first embodiment of the present invention. In the following description, a case will be described in which the AV amplifier device 1 reproduces 5-channel surround sound by simulating the diffuse surround system with five speakers arranged in the direct surround system. Here, for each of the five surround sound channels, the front left channel is L (Left) ch, the front right channel is R (Right) ch, the center channel is C (Center) ch, and the rear left channel is SL The (Surround Left) ch and the rear right channel are called SR (Surround Right) ch. Since the subwoofer is not directly related to the present invention, illustration and description thereof are omitted.

  The AV amplifier device 1 is arranged in a direct surround system by processing a surround sound signal (multi-channel sound signal) output from a sound reproduction device (DVD player 3, tuner 5 or the like) connected to the input side thereof. A multi-channel audio signal is output to the speakers 11 to 15, and the sound is reproduced by the diffuse surround method.

  As shown in FIG. 3, a listening position 90 for the listener U is provided slightly behind the center of the room 91. Around the listening position 90, five speakers are arranged by the direct surround method. That is, on the front left side, front right side, and front center side of the listening position 90, the Lch speaker 11, the Cch speaker 12, and the Rch speaker 13 that are front speakers are installed. In addition, on the rear left side and rear right side of the listening position 90, a rear speaker SLch speaker 14 and SRch speaker 15 are installed.

  The AV amplifier device 1 includes a digital audio interface receiver (DIR) 24, an A / D converter 25, a high definition multimedia interface (HDMI) (registered trademark) receiver 26, a DSP decoder 27, and a signal processing unit 29. The AV amplifier device 1 also includes a D / A converter 31, an LPF (low pass filter) 33, an amplifier 35, a controller 37, a storage unit 39, an operation unit 41, and a display unit 43.

  An audio playback device such as the DVD player 3 or the tuner 5 outputs an audio signal to the DIR 24, the A / D converter 25, or the HDMI (registered trademark) receiver 26, which is an input interface. Output to the DSP decoder 27.

  The DSP decoder 27 converts (decodes) an external input signal into a 5-channel digital sound signal (PCM signal) of Lch, Rch, Cch, SLch, and SRch, and outputs the signal to the signal processing unit 29.

  When an audio signal is input from the DSP decoder 27, the signal processing unit 29 has five speakers 11 to 15 arranged in the direct surround system, and the speaker position of the diffuse surround system (the Lds1ch of Lds1ch indicated by a star in FIG. 3). Signal processing is performed to localize the sound source at the sound source 18 (18P, 18V), the Lds2ch sound source 19 (19P, 19V), the Rds1ch sound source 20 (20P, 20V), and the Rds2ch sound source 21 (21P, 21V)). Do. Then, the signal processing unit 29 outputs five audio signals to the D / A converter 31. Details will be described later.

  The D / A converter 31 converts each input digital audio signal into an analog audio signal, the low-pass filter 33 removes noise in a band of 20 kHz or higher, and the amplifier 35 amplifies each audio signal, and the speaker 11 Output to ~ 15.

  The speakers 11 to 15 emit sound corresponding to the sound signal input from the amplifier 35.

  The controller 37 reads out and executes a control program from the storage unit 39, and controls each unit based on this program and according to an operation performed by the operation unit 41. For example, when a volume adjustment operation is performed on the operation unit 41, the controller 37 outputs a control signal corresponding to this operation to the amplifier 35 to change the volume. In addition, the controller 37 displays items to be transmitted to the user (listener) on the display unit 43.

  The storage unit 39 stores in advance information on the distance between the listening position 90 and the speakers 11 to 15 and information on the direction of the speakers 11 to 15 with respect to the listening position 90. This information is obtained by the well-known triangulation method. For example, when the AV amplifier device 1 is initially set up, microphones are installed at two or three different points in the vicinity of the listening position 90 and the test sound is emitted from the speakers 11 to 15 in order until sound is collected. It is obtained by measuring time and performing calculation by triangulation using this measurement time.

  Next, details of the signal processing unit 29 will be described. FIG. 4 is a block diagram showing the configuration of the signal processing unit of the AV amplifier apparatus according to the first embodiment of the present invention. The signal processing unit 29 includes a distribution unit 51, a localization addition unit 53, a crosstalk correction unit 55, a sound field generation unit 57, and an addition unit 59.

  Each unit of the signal processing unit 29 performs the following processing. The distribution unit 51 performs distribution (divided pressure) processing to localize the sound sources of Lds1ch, Lds2ch, Rds1ch, and Rds2ch, which are rear channels of the diffuse surround system, to positions corresponding to the channels by pan. The localization adding unit 53 corresponds to a characteristic providing unit, and generates an audio signal that feels as if the audio of Lds1ch, Lds2ch, Rds1ch, and Rds2ch is heard from a position (sound source) to be localized, based on the head-related transfer function. Perform virtual processing. The crosstalk correction unit 55 performs crosstalk correction (crosstalk cancellation processing) so that the sound emitted from the speaker is heard as a flat characteristic only by the ear on the speaker side. The sound field generation unit 57 corresponds to reflected sound generation means, and generates a sound signal of reflected sound generated when sound is emitted from the Lds1ch speaker and the Rds1ch speaker arranged by the diffuse surround system. The adding unit 59 adds the audio signal generated by the distributing unit 51, the audio signal generated by the localization adding unit 53 and the crosstalk correcting unit 55, and the audio signal generated by the sound field generating unit 57, and outputs the result.

  Specifically, each unit of the signal processing unit 29 performs signal processing as follows.

  The distribution unit 51 generates an audio signal to be emitted from the Lds1ch sound source 18P and an audio signal to be emitted from the Lds2ch sound source 19P from the SLch audio signal. Further, the distribution unit 51 generates a sound signal to be emitted from the Rds1ch sound source 20P and a sound signal to be emitted from the Rds2ch sound source 21P from the SRch sound signal. That is, the distribution unit 51 arranges the Lch speaker 11 and the SLch speaker 14 with respect to the viewing position 90 so that the sound source is localized by panning to the position of the sound source 18P of Lds1ch (left side of the listening position 90) shown in FIG. SLch audio signals (same channel audio signals) are distributed to the Lch at a ratio (for example, 6: 4) according to the ratio. The audio signal distributed to the Lch speaker 11 is added to the Lch audio signal by the adder 511. Also, the distribution unit 51 responds to the arrangement of the SLch speaker 14 and the SRch speaker 15 with respect to the viewing position 90 so that the sound source is localized by panning to the position of the Lds2ch sound source 19P (left rear of the listening position 90) shown in FIG. The SLch audio signal (same channel audio signal) is distributed to the SRch at the same ratio. The audio signal distributed to the SRch speaker 15 is added to the SRch audio signal by the adder 514.

  Similarly, the SRch sound signal is distributed to the Rch so that the sound source is localized by panning at the position of the sound source 20P of Rds1ch, and is added to the Rch sound signal by the adder 512. The SRch sound signal is distributed to the SLch so that the sound source is localized by panning at the position of the sound source 21P of Rds2ch, and is added to the SLch sound signal by the adder 513.

  In the localization adding unit 53, each of the filters of the Lds1 localization adding unit 531, the Lds2 localization adding unit 532, the Rds1 localization adding unit 541, and the Rds2 localization adding unit 542 has different filter coefficients based on the model head-related transfer functions and different ones. Delay time is set. Each of these units performs virtual processing in which the listener U is given a frequency characteristic that can be heard from a sound image in which the sound of each channel is virtually localized at a position corresponding to the channel around the listener U to the audio signal of each channel. For example, the Lds1 direct filter 531L is set with a filter coefficient and a delay time based on a model head-related transfer function from the position of the sound source 18V of the Lds1ch localized to the left side of the listener U to the left ear EL of the listener U. ing. The Lds1 cross filter 531R is set with a filter coefficient and a delay time based on a model head-related transfer function from the position of the sound source 18V of the Lds1ch that is localized on the left side of the listener U to the right ear ER of the listener U. . Although description is omitted, the filter coefficients and delay times based on the model head-related transfer function from each sound source to the left ear EL or the right ear ER are similarly set for each filter. The other localization adding units are similarly configured.

  With such a configuration, in the localization adding unit 53, the Lds1 localization adding unit 531 generates an audio signal having a frequency characteristic that feels audible from the position of the Lds1ch sound source 18V shown in FIG. 3 from the SLch audio signal. To do. The Lds2 localization adding unit 532 generates, from the SLch audio signal, an audio signal to which frequency characteristics that are felt to be heard from the position of the Lds2ch sound source 19V illustrated in FIG. The Rds1 localization adding unit 541 generates, from the SRch audio signal, an audio signal to which a frequency characteristic felt to be heard from the position of the sound source 20V of Rds1ch shown in FIG. The Rds2 localization adding unit 542 generates, from the SRch audio signal, an audio signal to which a frequency characteristic felt to be heard from the sound source localized at the position of the Rds2ch sound source 21V illustrated in FIG.

  The adder 535 adds the audio signals output from the Lds1 direct filter 531L and the Lds2 direct filter 532L. The adder 536 adds the audio signals output from the Lds1 cross filter 531R and the Lds2 cross filter 532R. Similarly, the adder 545 and the adder 546 add two signals.

  The adder 537 adds the audio signals output from the adder 535 and the adder 546 and outputs the result to the crosstalk correction unit 55. Similarly, the adder 547 adds the audio signals output from the adder 545 and the adder 536 and outputs the result to the crosstalk correction unit 55.

  In the crosstalk correction unit 55, a filter coefficient corresponding to an inverse function of the model head-related transfer function from the Lch speaker 11 to the left ear EL of the listener U is set in the Lch direct correction unit 551. The Lch direct correction unit 551 can flatten the characteristic that propagates from the position of the Lch speaker 11 to the left ear EL (one ear). Therefore, when the sound of Lds1ch is emitted from the Lch speaker 11 and propagates to the left ear EL of the listener U, it has a frequency characteristic that feels as if it is heard from the position of the sound source 18V of Lds1ch shown in FIG.

  Further, when the Lds2ch sound is emitted from the Lch speaker 11 and propagates to the left ear EL of the listener U, it has a frequency characteristic that can be heard from the position of the Lds2ch sound source 19V shown in FIG. Similarly, Rds1ch can be heard from a 20V position, and Rds2ch can be heard from a 21V position.

  The Lch cross correction unit 553 emits sound from the Lch speaker 11 illustrated in FIG. 3 and transmits to the right ear (the other ear) ER of the listener U so as not to hear the sound. This is to generate a sound that cancels the sound that wraps around and emits the sound from the Rch speaker 13. The Lch cross correction unit 553 reverses the phase of the signal input to the Lch direct correction unit 551 (the signal before direct correction), and gives a frequency characteristic that cancels the sound propagating from the Lch speaker 11 to the right ear ER of the listener U. Process.

  Therefore, if the listener who hears the sound based on the sound signal output from the Lch direct correction unit 551 and the sound based on the sound signal output from the Lch cross correction unit 553 is discussed only with the left ear, the sound is Lds1ch. Sound source 18V, Lds2ch sound source 19V, Rds1ch sound source 20V, and Rds2ch sound source 20V.

  Similarly, the Rch direct correction unit 555 and the Rch cross correction unit 557 perform signal processing on the audio signal output from the adder 547. Thus, if a listener who hears the sound based on the sound signal output from the Rch direct correction unit 555 and the sound based on the sound signal output from the Rch cross correction unit 557 is discussed only with the right ear, the sound is It feels like being heard from the position of the Rds1ch sound source 18V, the position of the Rds2ch sound source 19V, the position of the Rds1ch sound source 20V, and the position of the Rds2ch sound source 21V.

  The sound field generator 57 generates an audio signal of a reflected sound that is generated when the Lds1ch speaker and the Rds1ch speaker directly emit sound based on the reflected sound parameter.

  This reflected sound parameter is determined by the following method, for example. First, in an environment (room) similar to the user's viewing environment, as shown in FIG. 1B, speakers are arranged around the listening position in a diffuse surround manner. Further, as shown in FIG. 4B, four microphones that are not on the same plane and are arranged at predetermined intervals are installed at the listening position. Then, surround sound (test sound such as pulse and white noise) is emitted from a speaker arranged in the diffuse surround system, and acoustic measurement is performed by the well-known proximity four-point method using the four-point microphone. In the proximity 4-point method, test speech is picked up by a 4-point microphone, and the arrival time of the same reflected sound is obtained by correlation processing, etc., paying attention to slight differences in the time structure, and the distance from the four receiving points. Is used to determine the position of the equivalent reflected sound / virtual sound source. In the present invention, the reflected sound parameter is created based on the result of the acoustic measurement as described above. Therefore, the diffuse surround system is actually produced by emitting the reflected sound generated based on the reflection parameter from the speaker. Thus, the same acoustic effect as when the speaker is arranged can be obtained.

  The Lds1 sound field generation unit 571 and the Lds2 sound field generation unit 572 generate four audio signals so that the reflected sound can be reproduced three-dimensionally by four different speakers arranged in a rectangle. That is, the PLch that emits sound from the speaker arranged on the left front side of the viewing position, the PRch that emits sound from the speaker arranged on the right front side of the viewing position, the RLch that emits sound from the speaker arranged on the left rear side of the viewing position, and the viewing position These are four RRch audio signals to be emitted from a speaker arranged on the right rear side of the.

  The audio signals generated by the Lds1 sound field generation unit 571 and the Lds2 sound field generation unit 572 are added by an adder 573 to an adder 576 for each channel.

  The PLch audio signal added by the adder 573 is added to the audio signal output from the Rch cross correction unit 557 by the adder 591 and the audio signal output from the Lch direct correction unit 551 by the adder 592. The audio signal output from the adder 592 is added to the audio signal output from the adder 511 by the adder 595 and output to the D / A converter 31.

  The PRch audio signal added by the adder 574 is added to the audio signal output from the Rch direct correction unit 555 by the adder 593 and the audio signal output from the Lch cross correction unit 553 by the adder 594, respectively. The audio signal output from the adder 594 is added to the audio signal output from the adder 512 by the adder 596 and output to the D / A converter 31.

  The RLch audio signal added by the adder 575 is added to the audio signal output from the adder 513 by the adder 597 and output to the D / A converter 31.

  The RRch audio signal added by the adder 576 is added to the audio signal output from the adder 514 by the adder 598 and output to the D / A converter 31.

  As described above, in the AV amplifier device 1, the distribution unit 51 performs the panning on the Lds1ch sound source 18P, the Lds2ch sound source 19P, the Rds1ch sound source 20P, and the Rds2ch sound source 21P. Further, the localization adding unit 53 and the crosstalk correcting unit 55 virtually position the Lds1ch sound source 18V, the Lds2ch sound source 19V, the Rds1ch sound source 20V, and the Rds2ch sound source 21V by virtual processing using a head-related transfer function. Let

  Further, the localization position of the sound source provided by the distribution process in the distribution unit 51 and the localization position of the sound source provided by the virtual process in the localization addition unit 53 are set to coincide with each other. That is, the localization positions of the Lds1ch sound source 18P and the sound source 18V, the localization positions of the Lds2ch sound source 19P and the sound source 19V, the localization positions of the Rds1ch sound source 20P and the sound source 20V, and the localization positions of the Rds2ch sound source 21P and the sound source 21V are shown in FIG. As shown in the above, the same position is set. In order to set in this way, the configuration is as follows. For example, the controller (control unit) 37 outputs the position information of each sound source calculated based on the position information of the speakers 11 to 15 to the signal processing unit 29. Based on this position information, the signal processing unit 29 sets the distribution ratio of the audio signal in the distribution unit 51 and sets the head-related transfer function in the localization adding unit 53.

  As a result, the sense of localization and the sense of distance are unclear only by panning, but the sound source is localized at the same position as the localization position by panning by virtual processing, so that the sense of localization and sense of distance can be clarified.

  Furthermore, in the AV amplifier device 1, the sound field generator 57 generates and emits the reflected sound in the diffuse surround system, so that the surround feeling can be further enriched.

[Second Embodiment]
In the second embodiment, a case will be described in which the AV amplifier apparatus reproduces 5-channel surround sound by simulating the diffuse surround system with seven speakers arranged in the direct surround system. FIG. 5 is a block diagram showing a schematic configuration of an AV amplifier apparatus according to the second embodiment of the present invention. FIG. 6 is a block diagram showing a detailed configuration of the signal processing unit of the AV amplifier apparatus according to the second embodiment of the present invention. In the following description, only portions different from the configuration shown in FIG. 3 will be described.

  The AV amplifier device 1B processes the surround sound signals (multi-channel sound signals) output from the DVD player 3 and the tuner 5 connected to the input side thereof, and applies them to the speakers 11 to 17 arranged in the direct surround system. Outputs multi-channel audio signals and reproduces the sound using the diffuse surround method.

  As shown in FIG. 5, a PLch speaker 16 and a PRch speaker 17 are installed in a room 91 in addition to the speakers 11 to 15. The PLch speaker 16 is a loudspeaker for sound field control installed at the upper left front side of the listening position 90 of the listener U, that is, the upper left rear of the Lch speaker 11. The PRch speaker 17 is a sound field control speaker installed at the front right upper side of the listening position 90 of the listener U, that is, the rear right upper side of the Rch speaker 13.

  In the second embodiment, the AV amplifier apparatus 1B uses the PLch speaker 16 and the PRch speaker 17 to perform sound source localization by virtual processing and sound emission of the reflected sound of the surround sound.

  As shown in FIG. 5, the signal processing unit 29 </ b> B generates a 7-channel audio signal from the 5-channel audio signal input from the DSP decoder 27 and outputs the 7-channel audio signal to the speakers 11 to 17.

  Specifically, as shown in FIG. 6, the signal processing unit 29B is different from the signal processing unit 29 shown in FIG. 4 in the names of the respective parts of the crosstalk correction unit and the partial configuration of the addition unit. The crosstalk correction unit 55B outputs the audio signal subjected to the crosstalk cancellation process to the PLch speaker 16 and the PRch speaker 17. Therefore, each part of the crosstalk correction unit 55B is referred to as a PLch direct correction unit 551B, a PLch cross correction unit 553B, a PRch direct correction unit 555B, and a PRch cross correction unit 557B.

Each unit of the crosstalk correction unit 55B performs processing in which Lch is read as PLch and Rch is read as PRch in the description of the crosstalk correction unit 55.

  Further, in the signal processing unit 29B, a part of the configuration of the adding unit is different from the signal processing unit 29 illustrated in FIG. That is, the adder 59B adds the audio signal output by the adder 592B from the PL direct correction unit 551B and the audio signal output by the adder 591 and outputs the result to the D / A converter 31. The adding unit 594B adds the audio signal output from the PL cross correcting unit 553B and the audio signal output from the adder 593, and outputs the result to the D / A converter 31.

  With the above-described configuration, the AV amplifier apparatus 1B localizes the Lds1ch sound source 18P, the Lds2ch sound source 19P, the Rds1ch sound source 20P, and the Rds2ch sound source 21P by pan. Further, the Lds1ch sound source 18V, the Lds2ch sound source 19V, the Rds1ch sound source 20V, and the Rds2ch sound source 21V are virtually localized by virtual processing using a head-related transfer function.

  That is, in the AV amplifier device 1B, the distribution unit 51 distributes the Lds1ch audio signal to the Lch speaker 11 and the SLch speaker 14. The distribution unit 51 distributes the Lds2ch audio signal to the SLch speaker 14 and the SRch speaker 15. The distribution unit 51 distributes the Rds1ch audio signal to the Rch speaker 13 and the SRch speaker 15. The distribution unit 51 distributes the Rds2ch audio signal to the SLch speaker 14 and the SRch speaker 15.

  In the AV amplifier device 1B, the sound emitted from the Lds1ch sound source 18V, the Lds2ch sound source 19V, the Rds1ch sound source 20V, and the Rds2ch sound source 21V by the localization adding unit 53, the crosstalk correcting unit 55B, and the adding unit 59B. A signal is output to the PLch speaker 16 and the PRch speaker 17 and is virtually localized by virtual processing using a head-related transfer function.

  Further, in the AV amplifier device 1, the sound reflected by the diffuse surround system is generated by the sound field generation unit 57 and emitted from the PLch speaker 16, the PRch speaker 17, the SLch speaker 14, and the SRch speaker 15, so that a sense of surround sound is provided. It can be enriched.

  As a result, the sense of localization and the sense of distance are unclear only by panning, but the sound source is localized at the same position as the localization position by panning by virtual processing, so that the sense of localization and sense of distance can be clarified.

  In this embodiment, the audio signal output from the crosstalk correcting unit 55 is output to a presence speaker installed on the upper front side of the viewing position.

As described in Japanese Patent Application Laid-Open No. 2007-81927, sounds can be heard from the rear side of the listener based on the head-related transfer function of the rear channel audio signal from the two front speakers installed in front of the listener. When this characteristic is added and the crosstalk cancellation process is performed and this audio signal is output, a large dip occurs in the high frequency range. However, it is known that as the elevation angle from the listener's listening position to the presence speaker increases, the frequency at which the dip occurs gradually increases, and the dip improves when the elevation angle is set to a large value. Therefore, even if the crosstalk cancellation process is performed, it is possible to improve the sound quality of the sound source that is virtually localized on the rear side.

  Moreover, since the number of audio signals input to the Lch speaker 11 and the Rch speaker 13 can be reduced by emitting sound from the PLch speaker / PRch speaker, the S / N ratio can be improved. Further, since the crosstalk correction unit outputs the audio signal to the PLch speaker 16 and the PRch speaker 17 to which no other audio signal is input, it is possible to emit a sound with a good S / N ratio.

  In the second embodiment, the distribution unit 51 distributes the audio signal to the Lch speaker 11 and the Rch speaker 13. However, the present invention is not limited to this, and the PLch speaker 16 and the Rch speaker 13 are replaced with the Lch speaker 11. Alternatively, the audio signal can be distributed to the PRch speaker 17.

  Further, in the present embodiment, an example using five speakers arranged in the direct surround system has been shown. However, the present invention is not limited to this, and an RLch speaker and an RRch speaker are installed behind the listening position, and the LSch speaker and the RSch speaker are installed. It is possible to separate the components that have been mixed in the audio signal to be output.

  In addition, it is possible to reproduce three-dimensionally using virtual sound source distribution by installing eight speakers at the front, rear, right and left (eight corners of the room) of the listening position.

1-AV amplifier device 10-17-speaker 27-DSP decoder 29-signal processing unit

Claims (3)

An AV amplifier device that outputs audio signals of a plurality of channels to a plurality of speakers arranged on the front side and the rear side of a listening position,
Distributing means for distributing the audio signal of the same channel to the speakers arranged on the front side and the rear side of the listening position at a ratio according to the position where each channel should be localized;
A characteristic imparting means for imparting and outputting to the audio signal of each channel the frequency characteristic of the sound propagating from one position of the channel to the ear of the listener;
A crosstalk correcting means for generating and outputting a sound signal that cancels a sound audible to the listener's other ear when sound based on the sound signal output by the characteristic providing means is emitted from the speaker toward the listener; ,
The dispensing means;
AV amplifier device equipped with.   Based on the reflected sound parameter that reproduces the reflected sound of the sound emitted by the multiple speakers arranged in the diffuse surround system, the sound is output to the multiple speakers arranged in the direct surround system on the front side and the rear side of the listening position. The AV amplifier device according to claim 1, further comprising reflected sound generation means for generating an audio signal of the reflected sound.   The AV amplifier apparatus according to claim 1, wherein the crosstalk correcting unit outputs the audio signal to a presence speaker installed at a front upper side of a viewing position.

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