JP2004179711A - Loudspeaker system and sound reproduction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To localize the sound image in a proper sound image localizing direction to a listener even when the sound wave radiated from an array loudspeaker with a beam-like directivity is reflected on a wall and thereafter reaches the listener. <P>SOLUTION: Drive signals of the first loudspeaker units to radiate a reflection wave reflected on the wall and thereafter reaching the listener from the array loudspeaker and drive signals of the second loudspeaker units to radiate a direct wave directly reaching the listener are generated from a sound signal. A delay means adjusts the time difference between the arrival time of the reflection wave to the listener and the arrival time of the direct wave to the listener. The signals of the drive signals of the first loudspeaker units and the drive signals of the second loudspeaker units subjected to the time adjustment to be supplied to the same loudspeaker units are composed and the resulting signals are supplied to each loudspeaker unit. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a speaker device and an audio reproducing method using an array speaker in which a plurality of speaker units are arranged one-dimensionally or two-dimensionally.
[0002]
[Prior art]
A plurality of speaker units are arranged one-dimensionally or two-dimensionally, and a panel-type array speaker is arranged, for example, in front of a listening position. A speaker system for performing reproduction has been proposed (for example, see Japanese Patent Application Laid-Open No. 9-233588 (Patent Document 1) and Japanese Patent Application Laid-Open No. 6-205496 (Patent Document 2)).
[0003]
In this system, sound waves radiated from the array speaker are reflected as beam-like directivity on the side wall, rear wall, ceiling, etc. of the listener and reach the listener, as if the sound waves were finally reflected The sound is perceived as if there is a sound source in the direction of the wall, and sound image localization in any direction is possible with only one panel speaker arranged in front of the listener.
[0004]
[Patent Document 1]
JP-A-9-233588.
[Patent Document 2]
JP-A-6-205496.
[0005]
[Problems to be solved by the invention]
However, the above-described sound reproduction method using an array speaker has a problem that a sound image localization direction may be unnatural for a listener. For example, a case where sound reproduction of two channels on the left and right sides is performed by an array speaker will be described as an example. FIG. 12 is a diagram for describing a case where sound reproduction of left and right two channels is performed using the array speaker 1 in a room (listening room) having a width Rw and a depth Rd.
[0006]
In the case of this example, the array speaker 1 is arranged on the wall 3 side in front of the listener 2 at the center in the width direction of the room. The listener 2 listens to the reproduced sound from the array speaker 1 at an arbitrary position in the depth direction of the room at the center position in the width direction of the room.
[0007]
A plurality of unit drive signals to be supplied to each of a plurality of speaker units constituting the array speaker are generated from the input audio signal. In this case, the generated plurality of unit drive signals are the plurality of unit drive signals. By being supplied to the speaker unit, it is generated so that sound waves are emitted from the array speaker 1 with a desired beam-like directivity.
[0008]
In this case, each of the plurality of unit drive signals is generated such that the delay amount and the amplitude with respect to the input audio signal are adjusted, and the desired beam-like directivity is obtained.
[0009]
In the example of FIG. 12, for example, in the case of a sound wave by a left-channel audio signal emitted from the array speaker 1, the sound is reflected by the left wall 4 </ b> L of the listener 2 and reaches the listener 2 in FIG. 12. In FIG. 12, a plurality of unit drive signals are generated from the left channel sound signal such that the left channel sound wave is emitted from the array speaker 1 in the direction indicated by the solid line arrow 5L in FIG. Is done.
[0010]
The beam-shaped sound wave of the left channel emitted from the array speaker 1 in the direction of the solid arrow 5L is reflected by the wall surface 4L, propagates as indicated by the solid arrow 6L, and reaches the listener 2.
[0011]
Similarly, in the case of the sound wave by the right channel sound signal emitted from the array speaker 1, in FIG. 12, the sound wave is reflected on the right wall 4R of the listener 2 and reaches the listener 2. In FIG. 12, a plurality of unit drive signals are generated such that the right channel sound wave is emitted from the array speaker 1 in the direction indicated by the solid arrow 5R in FIG.
[0012]
The beam-shaped sound wave of the right channel emitted from the array speaker 1 in the direction of the solid arrow 5R is reflected by the wall surface 4R, propagates as indicated by the solid arrow 6R, and reaches the listener 2.
[0013]
That is, in the conventional speaker device, for convenience, in FIG. 12, when it is considered that the left channel sound wave and the right channel sound wave are emitted from the center position Pr0 of the array speaker 1, the position of the array speaker 1 and the position of the listener 2 are almost the same. The left and right channel sound waves were reflected at points PLref and PRref where the intermediate position was projected on the left and right wall surfaces 4L and 4R, and the reflected waves reached the listener and were listened to.
[0014]
As described above, according to the speaker device of FIG. 12, to each of the plurality of speaker units of the array speaker 1, a corresponding one of the plurality of unit drive signals generated from the left and right two-channel audio signals is supplied. Thus, the listener 2 can hear the two-channel stereo reproduction sound in which the sound image is localized to the left and right only by the sound wave from the one array speaker 1 at the center.
[0015]
In this case, the sound waves of the left and right channels are reflected by the left and right wall surfaces 4L and 4R, respectively, and reach the listener 2 while the actual speaker (array speaker 1) is present in front of the listener 2; The localization direction of the sound images of the left and right channels is the extension direction of the solid arrows 6L and 6R, and is applied to the listener 2 as if the sound waves of the left and right channels arrived from the imaginary speaker positions 1L and 1R indicated by dotted lines in FIG. Is heard.
[0016]
By the way, in the case of multi-channel surround reproduction of, for example, 5.1 channels, the left and right channel signals are localized at the intermediate positions between the front center position and the corners of the left wall surface 4L and the right wall surface 4R. The sound source signal is generally adjusted and recorded on a recording medium.
[0017]
However, as described above, in the case of the speaker device using the conventional array speaker in FIG. 12, the sound of the left and right channels is too far away from the assumed sound image localization position as described above. The sound is localized at the imaginary loudspeaker positions 1L and 1R, and a large gap is formed between the imaginary speaker and the localization direction of the sound image of the center channel. For this reason, it has an unnatural sound image localization feeling, and there is a drawback that connected and smooth sound image movement cannot be obtained.
[0018]
That is, with the conventional speaker device and the conventional sound reproducing method, it is very difficult to match the sound image localization direction for the sound of each channel with the sound image localization direction assumed in advance.
[0019]
In the case of the conventional example of FIG. 12 as well, in principle, the beam-shaped sound waves emitted from the array speaker 1 are reflected many times on the left and right wall surfaces, the rear wall surface, the ceiling, etc. The sound wave reflection position that reaches the listener last is made to be a sound image localization direction position that is assumed in advance for the sound of each channel, and the sound image localization direction of the sound of the channel is assumed to be the sound image localization direction. It seems possible to make them match.
[0020]
However, it is almost impossible to narrow down the directivity like a light beam due to the limitation of the size of the array speaker and the wavelength of the sound wave, and it is necessary to make the light reflected on the wall many times to reach the listener. In this case, the path length of the sound wave becomes very long, and the distance attenuation of the sound wave becomes large. In addition, the wall usually does not completely reflect the sound wave but partially absorbs the sound wave, so that the sound wave is greatly attenuated according to the number of reflections. Therefore, as described above, it is actually extremely difficult to reflect the sound waves emitted from the array speaker many times on the wall surface and localize in the sound image localization direction assumed for each channel. Can be
[0021]
In view of the above, the present invention is suitable for a listener even in a case where sound waves radiated from an array speaker with beam-like directivity reach a listener after being reflected by a wall. An object is to enable sound image localization in the sound image localization direction.
[0022]
[Means for Solving the Problems]
In order to solve the above problems, a speaker device according to the present invention
An array speaker composed of a plurality of speaker units;
Receiving an input audio signal and generating a first plurality of unit drive signals to be supplied to the plurality of speaker units of the array speaker, wherein the first plurality of unit drive signals are the plurality of unit drive signals; A first directivity generating the first plurality of unit drive signals such that a direction of a main axis of directivity of sound waves emitted from the array speaker by being supplied to the speaker unit is set to a first direction; Forming signal generation means;
Receiving the input audio signal and generating a second plurality of unit drive signals to be supplied to the plurality of speaker units of the array speaker, wherein the second plurality of unit drive signals are the plurality of unit drive signals; The second plurality of unit drive signals so that the direction of the main axis of directivity of sound waves emitted from the array speaker by being supplied to the speaker unit is set to a second direction different from the first direction. Second directivity forming signal generating means for generating
The first directivity forming signal generating means is provided on either the input side or the output side of the first directivity forming signal generating means, or the input side or the output side of the second directivity forming signal generating means. The time at which the sound wave radiated with the direction of the directional main axis reaches the listener, and the time at which the sound wave radiated from the array speaker with the second direction as the direction of the directional main axis reaches the listener. Delay means for adjusting the difference between
A signal that supplies the first plurality of unit drive signals and the second plurality of unit drive signals time-adjusted by the delay unit to the same speaker unit, and synthesizes each of the speaker units. To supply
It is characterized by the following.
[0023]
According to the present invention having the above-described configuration, sound is localized from the array speaker in a direction in which the first direction is the direction of the main axis of directivity, and the second direction is in the direction of the main axis of directivity. An intermediate position with respect to the sound image localization direction by the sound wave is the sound image localization direction corresponding to the input audio signal.
[0024]
That is, in the conventional speaker device, the sound image localization direction of each audio channel with respect to the listener is fixedly determined only by the reflected wave from one wall, whereas according to the speaker device of the present invention, the sound image The localization direction is an intermediate position between the sound image localization directions of the two sound waves from the array speaker.
[0025]
For example, when the audio signal of the right channel is an input signal, the array speaker emits sound waves in the first direction as reflected from the right side wall of the listener to reach the listener, As the second direction, sound waves are emitted in a direction that directly reaches the listener. Then, the timing at which the sound waves emitted in the first and second directions reach the listener is adjusted.
[0026]
Then, the listener can hear as if the sound image of the right channel is localized in the middle direction between the sound wave arriving by reflecting from the right side and the sound wave arriving directly. Therefore, for example, in multi-channel surround playback, there is no large gap between the center channel and the localization direction, and there is an effect that a smooth sound image movement with connection can be obtained.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a speaker device and a sound reproduction method according to the present invention will be described with reference to the drawings.
[0028]
FIGS. 1 and 2 show an audio-visual system in which a speaker device according to the present invention monitors an image displayed on a screen of a video reproducing device and reproduces and listens to sound associated with the image. 2 shows an example of a system configuration when used as a unit. In this example, the listening environment (listening room) is a room like a normal rectangular parallelepiped, and there are wall surfaces 14L and 14R on the left and right sides of the listener 12, and a ceiling 14C above the listener 12. , The listener is sitting on a chair placed on the floor 14G.
[0029]
In this example, a projection screen 11 for displaying an image projected by a video projector 13 (see FIG. 2) is provided on the front wall 14F side of the room viewed from the listener 12. Below this projection screen 11, the speaker device 10 of this embodiment is arranged. In this example, the listener 12 is seated so that the projection screen 11 is viewed from the front.
[0030]
The speaker device 10 of this embodiment includes an array speaker and an array speaker audio signal generation circuit. As described above, the array speaker is one in which a plurality of speaker units are arranged one-dimensionally or two-dimensionally, and the audio signal generation circuit for the array speaker includes a left-channel audio signal and a right-channel audio signal. A plurality of unit drive signals to be supplied to each of the plurality of speaker units are formed from each of the audio signals of each channel such as a signal.
[0031]
[Configuration example of array speaker]
FIG. 3A shows a configuration example of the array speaker 20 in this embodiment. The array speaker 20 in the example of FIG. 3A is an example in which a plurality of speaker units 21 are arranged in a two-dimensional array, and in the horizontal direction and the height direction, a large number of speaker units having the same size in this example. Units 21 are arranged.
[0032]
Here, arranging the plurality of speaker units 21 means arranging the plurality of speaker units 21 side by side so that all the diaphragms 21v face the outside from the unit mounting plate 22 surface. ing. In the example of FIG. 3, the speaker unit 21 includes a circular diaphragm 21v, and the main axes of the vibration direction of the diaphragm 21v are all set to be orthogonal to the mounting plate 22.
[0033]
In this example, the speaker unit 21 is, for example, a unit having a diameter of 8 cm, and has a constant interval Dw in the horizontal direction and a constant interval Dh in the height direction, and has a square lattice shape as shown in FIG. Are arranged.
[0034]
Here, the arrangement intervals Dw and Dh are intervals between the centers (unit centers) of the diaphragms 21v of the adjacent speaker units 21, and in this example, for example, Dw = Dh = 10 cm.
[0035]
In this case, as shown in FIG. 3A, the distance from the center of the leftmost unit in the horizontal direction of the plurality of speaker units 21 constituting the array speaker 20 to the center of the rightmost unit (hereinafter, this distance is referred to as the distance). The unit arrangement width is W, and the distance from the center of the lower end of the plurality of speaker units to the center of the upper end (hereinafter, this distance is referred to as the unit arrangement height) is H. .
[0036]
Generally, the arrangement intervals Dw and Dh of the plurality of speaker units 21 in the array speaker 20 determine a controllable high-frequency limit frequency of the directional characteristics of the entire array speaker 20. The unit arrangement width W and the unit arrangement height H of the array speaker 20 determine a controllable low-frequency limit in the width and height directions, respectively, of the directional characteristics of the entire array speaker 20.
[0037]
Therefore, in order to obtain an arbitrary directional characteristic from low to high in the array speaker 20, it is necessary to arrange a large number of small speaker units at small intervals and to make the unit arrangement width W and the unit arrangement height H sufficiently large. desirable.
[0038]
However, it is practically difficult to make the size of the entire array speaker 20 extremely large. In addition, laying down a very large number of small speaker units involves an increase in cost and manufacturing difficulty. The arrangement intervals Dw, Dh, the unit arrangement width W, and the unit arrangement height H of the speaker units 21 are determined according to the intended use.
[0039]
In the low-frequency range having a long wavelength, the ability to discriminate the direction of the sound source of the listener is low. Therefore, in practice, it is considered that the beam-like directivity in the low-frequency range is unnecessary, and in that respect, the unit arrangement width of the array speaker 20 is considered. The W and the unit arrangement height H do not need to be so large, and for example, about several tens cm to 1 m is sufficient.
[0040]
When a multi-channel surround signal is reproduced, the sound image is localized in the direction around the listener 12. However, the discrimination ability in the height direction is lower than that in the horizontal direction. It is not necessary to make the directivity characteristic beam-like as strictly as the direction.
[0041]
Therefore, the arrangement interval Dh in the height direction of the speaker units 21 may be slightly wider. Further, the unit arrangement height H of the array speaker 20 can be smaller than the unit arrangement width W. Since an actual speaker unit has a narrow directivity in a high frequency range due to the size of its aperture, it is easy to obtain a narrow directivity even when an array speaker 20 having a small number of speaker units 21 in the height direction is configured. It is.
[0042]
Therefore, in an extreme case, as shown in FIG. 3B, the linear array speaker 20 is configured such that the diaphragms 21v of the plurality of speaker units 21 are arranged on the mounting plate 22 in a one-dimensional horizontal direction. An appropriate effect can be obtained only by controlling the directivity in the horizontal direction. In the case of the linear array speaker 20 shown in FIG. 3B, the directivity basically has a rotationally symmetric shape about the arrangement axis of the speaker unit 21.
[0043]
In FIG. 3, the arrangement intervals Dw and Dh of the speaker units 21 are fixed. However, for example, the speaker units 21 are arranged close to each other at the center, and the intervals between the speaker units 21 are increased toward the periphery. They may be arranged. In such a case, the number of speaker units 21 used as the entire array speaker 20 can be reduced.
[0044]
When the speaker units 21 are two-dimensionally arranged as shown in FIG. 3A, the diaphragms 21v of the speaker units 21 are not arranged in a square lattice as in the above-described example, but are arranged in a staggered manner. By arranging them in a lattice, the arrangement intervals Dw and Dh of the speaker units 21 can be equivalently reduced.
[0045]
Further, in the above-described example, the plurality of speaker units constituting the array speaker 20 have a large number of speaker units having the same diameter and the same characteristics, but a high-range unit (tweeter) and a mid-low range unit. Alternatively, a full range unit may be combined and arranged. In addition to the above, a variety of arrangement methods of the array speaker can be considered. In the present invention, the form of the array speaker is not limited as long as the directional characteristics at least in the horizontal direction can be controlled particularly in the mid-high range.
[0046]
[Audio signal generation circuit for array speaker]
As described above, a unit drive signal is supplied from the array speaker audio signal generation circuit to each speaker unit 21 of the array speaker 20 configured by arranging the plurality of speaker units 21. The array speaker audio signal generation circuit generates a plurality of speaker unit drive signals to be supplied to each of the plurality of speaker units 21 from the audio signal of each channel.
[0047]
An example of an audio signal generation circuit for an array speaker when the input audio signal has two channels will be described below. FIG. 4 is a block diagram showing the overall configuration of the array speaker audio signal generation circuit.
[0048]
In the case of the array speaker audio signal generation circuit of this example, as shown in FIG. 4, a first channel signal generation circuit 41, a second channel signal generation circuit 42, a control circuit 43, a first channel , 46n (n is the number of speaker units 21), output amplifiers 471, 472, 473,... , 47n (n is the number of speaker units 21). The control circuit 43 includes, for example, a microcomputer.
[0049]
The first-channel signal generation circuit 41 and the second-channel signal generation circuit 42 have the same configuration, and respectively include the first directivity forming signal generation circuits 411 and 421 and the second directivity forming circuit. Signal generating circuits 412 and 422, delay / amplitude adjusting circuits 413 and 423, and combining circuits 414 and 424, and receives input audio signals of the first and second channels from audio input terminals 48 and 49. .
[0050]
The first directivity forming signal generation circuits 411 and 421 receive an array based on the control signals CT11 and CT21 from the control circuit 43 from the input audio signals of the respective channels input through the audio input terminals 48 and 49, respectively. The first plurality of unit drive signals U11 and U21 to be supplied to the plurality of speaker units 21 of the speaker 20 are generated. The first plurality of unit drive signals U11 and U21 determine the direction of the main axis of the directivity of the sound wave radiated from the array speaker 20 in the form of a beam by the first control signals CT11 and CT21 from the control circuit 43. It is generated to be a direction.
[0051]
Similarly, the second directivity forming signal generation circuits 412 and 422 output a plurality of speaker units of the array speaker 20 based on the control signals CT12 and CT22 from the control circuit 43 from the input audio signals of the respective channels. The second plurality of unit drive signals U12 and U22 to be supplied to 21 are generated. The second plurality of unit drive signals U12 and U22 determine the direction of the main axis of the directivity of the sound wave radiated from the array speaker 20 in the form of a beam by the control signals CT12 and CT22 from the control circuit 43. It is generated to be a direction.
[0052]
The delay / amplitude adjustment circuits 413 and 423 determine the time required for the sound wave (hereinafter, referred to as the first beam sound wave) radiated from the array speaker 20 in the first direction to reach the listener 12, From the time at which the sound wave radiated in the form of a beam in the second direction (hereinafter, referred to as a second beam sound wave) reaches the listener 12, and adjusts the level of the first beam sound wave. It is for doing.
[0053]
The delay / amplitude adjustment circuits 413 and 423 are controlled in delay time and amplitude (level) by control signals CT10 and CT20 from the control circuit 43.
[0054]
The control circuit 43 is supplied with an adjustment operation signal from the first channel adjustment operation section 44 and an adjustment operation signal from the second channel adjustment operation section 45. The first channel adjustment operation unit 44 includes a knob 51 for adjusting the direction of the main axis of the directivity of the first beam sound wave of the first channel, a knob 52 for adjusting the amplitude of the first beam sound wave, and the first channel. Knob 53 for adjusting the direction of the main axis of the directivity of the second beam sound wave of the channel, knob 54 for adjusting the amplitude of the second beam sound wave, knob 55 for adjusting the delay time of the first channel, and knob for amplitude adjustment 56 are provided.
[0055]
Similarly, the second channel adjustment operation unit 45 includes a knob 61 for adjusting the direction of the main axis of the directivity of the first beam sound wave of the second channel, and a knob 62 for adjusting the amplitude of the second beam sound wave. A knob 63 for adjusting the main axis of the directivity of the second beam sound wave of the second channel, a knob 64 for adjusting the amplitude of the second beam sound wave, a knob 65 for adjusting the delay time of the second channel, and the amplitude An adjustment knob 66 is provided.
[0056]
When the direction adjusting knob 51 is adjusted, a portion related to the delay amount control of the control signal CT11 is adjusted, and the control signal CT11 causes the first directivity forming signal generation circuit 411 of the first channel to output. The direction (first direction) of the main axis of the directivity of the first beam-shaped sound wave determined by the first unit drive signal U11 is adjusted. Further, when the amplitude adjusting knob 52 is adjusted, a portion related to the amplitude control of the control signal CT11 is adjusted, and the amplitude of the first beam sound wave determined by the first unit drive signal U11 is adjusted by the control signal CT11. (Level) is adjusted.
[0057]
In addition, when the direction adjusting knob 53 is adjusted, a portion related to the delay amount control in the control signal CT12 is adjusted, and the control signal CT12 causes the second directivity forming signal generation circuit 412 of the first channel to output a signal. The direction (second direction) of the main axis of the directivity of the second beam sound wave determined by the second unit drive signal U12 is adjusted. Further, when the amplitude adjusting knob 54 is operated to adjust, the portion related to the amplitude control in the control signal CT12 is adjusted, and the amplitude of the second beam sound wave determined by the second unit drive signal U12 is adjusted by the control signal CT12. (Level) is adjusted.
[0058]
In addition, when the direction adjusting knob 61 is adjusted, a portion related to the delay amount control in the control signal CT21 is adjusted, and the control signal CT21 outputs the signal from the first directivity forming signal generation circuit 421 of the second channel. The direction (first direction) of the main axis of the directivity of the first beam sound wave determined by the first unit drive signal U21 is adjusted. Further, when the amplitude adjusting knob 62 is adjusted, a portion related to the amplitude control of the control signal CT21 is adjusted, and the amplitude of the first beam-shaped sound wave determined by the first unit drive signal U21 is adjusted by the control signal CT21. (Level) is adjusted.
[0059]
In addition, when the direction adjusting knob 63 is adjusted, a portion related to the delay amount control in the control signal CT22 is adjusted, and the control signal CT22 causes the second directivity forming signal generation circuit 422 of the second channel to output the control signal CT22. The direction (second direction) of the main axis of the directivity of the second beam sound wave determined by the second unit drive signal U22 is adjusted. In addition, when the amplitude adjusting knob 64 is adjusted, a portion related to the amplitude control of the control signal CT22 is adjusted, and the amplitude of the second beam sound wave determined by the second unit drive signal U22 by the control signal CT22. (Level) is adjusted.
[0060]
Further, when the delay amount adjusting knob 55 is adjusted, a portion related to the delay amount control in the control signal CT10 is adjusted, and the delay time in the delay / amplitude adjustment circuit 413 of the first channel is adjusted by the control signal CT10. Is done. In addition, when the amplitude adjusting knob 56 is adjusted, a portion related to the amplitude control of the control signal CT10 is adjusted, and the amplitude (level) of the input signal in the delay / amplitude adjusting circuit 413 is adjusted by the control signal CT10. Is adjusted.
[0061]
Further, when the delay amount adjusting knob 65 is operated to adjust, a portion related to the delay amount control in the control signal CT20 is adjusted, and the delay time in the delay / amplitude adjustment circuit 423 of the second channel is adjusted by the control signal CT20. Is done. In addition, when the amplitude adjusting knob 66 is adjusted, a portion related to the amplitude control of the control signal CT20 is adjusted, and the amplitude (level) of the input signal in the delay / amplitude adjusting circuit 423 is adjusted by the control signal CT20. Is adjusted.
[0062]
As described above, the first and second unit drive signals U11 and U12 generated by the first and second directivity forming signal generation circuits 411 and 412 of the first channel are output to the speaker unit of the array speaker 20. The signals supplied to the same speaker unit among the 21 are combined by the combining circuit 414 to form the same number of combined unit drive signals U10 as the number of the speaker units 21 of the array speaker 20.
[0063]
In FIG. 4, the number of the combining circuits 414 is shown as one, but the number is actually the same as the number of the speaker units 21. Further, the synthesizing circuit 414 connects the output signal lines of the first and second directivity forming signal generation circuits 411 and 412 which are signals to be supplied to the same speaker unit among the respective output signal lines. By doing so, it can also be configured.
[0064]
.., 46n and output amplifiers 471, 472, 473,..., 47n (n Is supplied to each of the corresponding speaker units 21 through the corresponding number of speaker units 21).
[0065]
Similarly, the first and second unit drive signals U21 and U22 generated by the first and second directivity forming signal generation circuits 421 and 422 of the second channel are output from the speaker unit 21 of the array speaker 20. The signals supplied to the same speaker unit are combined by the combining circuit 424 to form the same number of combined unit drive signals U20 as the number of the speaker units 21 of the array speaker 20.
[0066]
.., 46n and the output amplifiers 471, 472, 473,..., 47n with the first channel combined unit drive signal U10. Is supplied to each of the corresponding speaker units 21.
[0067]
The first directivity forming signal generation circuits 411 and 421 and the second directivity forming signal generation circuits 412 and 422 have exactly the same configuration, and each include the same number of filter circuits as the number of speaker units 21. . FIG. 5 shows a configuration example of the first and second directivity forming signal generation circuits 411 and 412 of the first channel signal generation circuit 41.
[0068]
That is, in the example shown in FIG. 5, the first directivity forming signal generation circuit 411 includes the same number of filter circuits 711, 712, 713,... The formation signal generation circuit 412 includes the same number of filter circuits 721, 722, 723,..., 72n as the number of the speaker units 21.
[0069]
The control signals CT11 and CT12 from the control circuit 43 are, as shown in FIG. 5, the filter circuits 711, 712, 713,..., 71n of the first directivity forming signal generation circuit 411 and the first directivity. .., 72n of the formation signal generation circuit 411 are a bundle of a plurality of control signals individually supplied to each of the filter circuits 721, 722, 723,.
[0070]
Each of the filter circuits 711, 712, 713, ..., 71n and the filter circuits 721, 722, 723, ..., 72n is constituted by, for example, an analog filter or a digital filter. In the case of being constituted by a digital filter, the input audio signal from the audio input terminal 48 is converted into a digital audio signal, or in the input stages of the first and second directivity forming signal generation circuits 411 and 412, It needs to be converted to a digital audio signal.
[0071]
When each of the filter circuits 711, 712, 713, ..., 71n and the filter circuits 721, 722, 723, ..., 72n is constituted by an analog filter, for example, the capacitance value of the variable capacitance element or the variable resistor Is adjusted by the control signals CT11 and CT12 to adjust the delay time and the amplitude. In the case of using a digital filter, the control signals CT11 and CT12 are a bundle of a set of filter coefficients to be supplied to each filter circuit, and the delay time is controlled by changing the filter coefficient values of these sets. And the amplitude is adjusted.
[0072]
[Embodiment of sound reproduction method]
Next, a case where sound signals of two channels on the left and right sides are acoustically reproduced using the array speaker audio signal generation circuit and the array speaker 20 configured as described above will be described.
[0073]
In the example described below, in the first channel signal generation circuit 41 and the second channel signal generation circuit 42, the delay / amplitude adjustment circuits 413 and 423, the first directivity forming signal generation circuits 411 and 421, and All of the two directivity forming signal generation circuits 412 and 422 are configured as digital circuits.
[0074]
Therefore, in the case of this example, each of the filter circuits 711 to 71n and 721 to 72n is constituted by a digital filter, and the control signals CT11, CT21 and CT12, CT22 are respectively provided by the filter circuits 711 to 71n and 721 to 72n. Is a set of a plurality of filter coefficients supplied to. Then, the values of the filter coefficients of each set are changed by adjusting the adjustment knobs 51 to 54 and 61 to 64. The delay / amplitude adjustment circuits 413 and 423 also have a digital filter configuration, and the control signals CT10 and CT20 are a bundle of filter coefficient sets.
[0075]
In this case, for example, the control circuit 43 includes a set of filter coefficients for the filter circuits 711 to 71n and 721 to 72n for sequentially changing the direction of the main axis of the directivity of the beam sound wave, for example, a nonvolatile memory. The set of filter coefficients read from the memory is changed according to the adjustment of the adjustment knobs 51 to 54 and 61 to 64, so that the direction of the main axis of the directivity of the beam sound wave and The amplitude of the beam sound wave is changed.
[0076]
First, in FIG. 4, in this example, a digital audio signal of the left channel is supplied through the audio input terminal 48 of the first channel. The digital audio signal of the right channel is supplied through the audio input terminal 49 of the second channel. First, an operation of generating a unit drive signal U10 for driving the plurality of speaker units 21 from the digital signal of the left channel will be described.
[0077]
In this embodiment, the second directivity forming signal generation circuit 412 of the first channel signal generation circuit 41 converts the left channel digital audio signal through the audio input terminal 48 into a solid arrow 15L in FIG. As shown in the figure, a beam-like sound wave (reflected wave) BLref that propagates as shown by the solid arrow 16L after reaching the left wall surface 14L and reaches the listener 12 is generated from the array speaker 20. The second unit drive signal U12 is generated.
[0078]
As described above, the direction of the main axis of the directivity of the beam of the reflected wave BLref is adjusted by the direction adjusting knob 53. Further, the amplitude of the beam of the reflected wave BLref is adjusted by the amplitude adjusting knob 54.
[0079]
Further, in the first directivity forming signal generation circuit 411 of the first channel signal generation circuit 41, the digital audio signal of the left channel passed through the delay / amplitude adjustment circuit 413 is indicated by a solid arrow 17L in FIG. Then, a first unit drive signal U11 for generating a beam-like sound wave (direct wave) BLdir for directly reaching the listener 12 from the array speaker 20 is generated.
[0080]
As described above, the direction of the main axis of the directivity of the beam of the direct wave BLdir is adjusted by the direction adjusting knob 51. The amplitude of the beam of the direct wave BLdir is adjusted by the amplitude adjustment knob 52.
[0081]
In this case, when the amplitude gain of the delay / amplitude adjustment circuit 413 is “1” (the amplitude of the input signal does not increase or decrease), the level of the reflected wave BLref and the level of the direct wave BLdir become equal in the listener 12. The amplitude is adjusted in the first directivity forming signal generation circuit 411 and the second directivity forming signal generation circuit 412.
[0082]
By the way, the path length of the beam sound BLdir that reaches the listener 12 directly is shorter than the path length of the beam sound BLref that reaches the listener 12 after being reflected by the wall, so that both the sound waves BLdir and BLref are simultaneously arrayed. When emitted from the speaker 20, the direct wave BLdir reaches the listener 12 earlier. Moreover, the level of the reflected wave BLref becomes smaller than that of the direct wave BLdir due to the distance attenuation due to the path length and the partial sound absorption by the reflecting wall. When the listener listens to both of the sound waves BLdir and BLref, the sound image is localized substantially in the front direction based on the principle of preceding sound localization.
[0083]
The delay / amplitude adjustment circuit 413 solves the problem relating to the arrival time. That is, in the case of this example, the delay adjustment processing is performed on the direct wave BLdir by adjusting the adjustment knob 55. By performing the delay adjustment processing, the two beam sound waves BLdir and BLref are adjusted so as to simultaneously reach the listener.
[0084]
Further, of the above problems, the problem relating to the difference in level can be solved by the amplitude adjusting function of the filter circuits constituting the first directivity forming signal generation circuit 411 and the second directivity forming signal generation circuit 412. The problem can also be solved by using the amplitude adjustment function of the delay / amplitude adjustment circuit 413.
[0085]
When the sound waves BLdir and BLref reach the listener 12 at substantially the same level at the same time, a sense of sound image localization can be obtained in an intermediate direction between them. This is the same phenomenon that in a normal stereo system, when the same signal is input to the left and right speakers, the sound image is localized at an intermediate position (phantom center).
[0086]
The unit drive signals U11 and U12 formed as described above are combined with each other to be supplied to the same speaker unit 21 and then transmitted to the respective speaker units 21 through the channel combining circuits 431 to 43n and the output amplifiers 441 to 44n. Supplied. As a result, both beam sound waves BLdir and BLref are radiated from the array speaker 20 so as to reach the listener 12 simultaneously and at the same level.
[0087]
As a result, the listener 12 simultaneously listens to the beam sound BLref from the direction indicated by the solid arrow 16L and the beam sound BLdir from the direction indicated by the solid arrow 17L. As indicated by the solid line arrow 18L, the user listens as if the sound of the left channel arrived from an intermediate direction between the arrival direction of the beam sound BLdir and the arrival direction of the beam sound BLref.
[0088]
That is, the sound image of the left channel sound is a predetermined position between the position of the center array speaker 20 and the left wall surface 14L where the left channel sound signal is scheduled (see FIG. 6, the imaginary speaker position 20L). ), The listener 12 can listen.
[0089]
Here, when the levels of both beam sound waves BLdir and BLref are equal, the sound image localization position of the sound of the left channel is in the middle direction between the arrival direction of beam sound wave BLdir and the arrival direction of beam sound wave BLref. However, when the intensities of both beam sound waves BLdir and BLref are different, the sound image localization position of the left channel sound is in a direction deviated to the arrival direction of the larger amplitude beam sound waves.
[0090]
Further, by adjusting the levels of the reflected wave BLref and the direct wave BLdir, the sound image localization direction can be changed in the left-right direction. Similarly, the sound image localization direction can be changed by increasing or decreasing the delay time given to the direct wave BLdir.
[0091]
Therefore, by adjusting the amplitude adjustment knobs 52 and 54 to adjust the amplitude of the beam sound waves BLdir and BLref, or instead of, or in addition to, the adjustment, the amplitude adjustment knob 56 is used. By controlling the signal amplitude by the delay / amplitude adjustment circuit 413 to adjust the amplitude of the beam sound wave BLdir, the left and right positions between the position of the center array speaker 20 and the left wall surface 14L are adjusted. The sound image localization position of the channel sound can be adjusted in a direction deviated from the arrival direction of the beam sound wave having a larger amplitude.
[0092]
Further, by adjusting the delay amount adjusting knob 55 to adjust the delay time given to the direct wave BLdir, it is possible to adjust the sound image localization direction by the audio signal of the left channel.
[0093]
The digital audio signal of the right channel supplied from the audio input terminal 49 to the signal generation circuit 42 for the second channel is subjected to exactly the same processing as described above. In FIG. 6, a beam-shaped sound wave (reflected wave) that reflects from the digital audio signal of the channel to the right wall surface 14R as shown by a solid arrow 15R and then reaches the listener 12 as shown by a solid arrow 16R in FIG. 2.) Generate a second unit drive signal U22 for causing BRref to be generated from the array speaker 20.
[0094]
As described above, the direction of the main axis of the directivity of the beam of the reflected wave BRref is adjusted by the direction adjusting knob 63. The amplitude of the beam of the reflected wave BRref is adjusted by the amplitude adjustment knob 64.
[0095]
In the first directivity forming signal generation circuit 421 of the second channel signal generation circuit 42, the digital audio signal of the left channel passed through the delay / amplitude adjustment circuit 423 is used as shown by a solid arrow 17R in FIG. Then, a first unit drive signal U21 for generating a beam-shaped sound wave (direct wave) BRdir for directly reaching the listener 12 from the array speaker 20 is generated.
[0096]
As described above, the direction of the main axis of the directivity of the beam of the direct wave BRdir is adjusted by the direction adjusting knob 61. The amplitude of the beam of the sound wave BRdir is adjusted by an amplitude adjustment knob 62.
[0097]
Then, the delay time of the delay / amplitude adjustment circuit 423 is adjusted by the adjustment operation of the adjustment knob 65 so that the two beam sound waves BRdir and BRref reach the listener 12 simultaneously. In addition, the delay / amplitude is adjusted by an amplitude adjusting function in a filter circuit constituting the first directivity forming signal generation circuit 421 and the second directivity forming signal generation circuit 422, instead of or in addition to this. By using the amplitude adjustment function of the adjustment circuit 423, the two beam sound waves BRdir and BRref are adjusted so as to reach the listener at the same level.
[0098]
The unit drive signals U21 and U22 formed as described above are combined with each other to be supplied to the same speaker unit 21 and then transmitted to the respective speaker units 21 through the channel combining circuits 431 to 43n and the output amplifiers 441 to 44n. Supplied. Thereby, both beam sound waves BRdir and BRref are radiated from the array speaker 20 so as to reach the listener 12 simultaneously and at the same level.
[0099]
As a result, the listener 12 simultaneously listens to the beam sound wave BRref from the direction indicated by the solid arrow 16R and the beam sound wave BRdir from the direction indicated by the solid arrow 17R. As shown in the figure, the right-channel sound is heard as if it arrived from an intermediate direction between the arrival direction of the beam sound wave BRdir and the arrival direction of the beam sound wave BRref.
[0100]
That is, the sound image of the right channel sound is a predetermined position (see the imaginary speaker position 20R in FIG. 6) between the position of the center array speaker 20 and the left wall surface 14R where the right channel sound signal is scheduled. ), The listener 12 can listen.
[0101]
In the same manner as in the case of the left-channel audio signal described above, the right-channel audio signal is also changed in its left-right direction by adjusting the levels of the reflected wave BRref and the direct wave BRdir. Can be done. Similarly, the sound image localization direction can be changed by increasing or decreasing the delay time given to the direct wave BRdir.
[0102]
In other words, by adjusting the amplitude adjustment knobs 62 and 64 to adjust the amplitude of the beam sound waves BRdir and BRref, the amplitude adjustment knob 66 is adjusted, and the signal amplitude is controlled by the delay / amplitude adjustment circuit 423. In this way, by adjusting the amplitude of the beam sound wave BRdir, the sound image localization position of the right channel sound between the position of the center array speaker 20 and the right wall surface 14R can be adjusted by the beam sound wave having a larger amplitude. It can be adjusted in a direction deviated from the arrival direction.
[0103]
As described above, according to this embodiment, it is possible to localize the sound image based on the audio signals of the left and right channels at the desired sound image localization position, and obtain a good sound reproduction space. Therefore, in the multi-channel surround reproduction, when the sound wave by the audio signal of the center channel is emitted from the array speaker 20 so as to directly reach the listener 12, an unnatural sound image localization feeling as in the related art is eliminated. There is an effect that a smooth sound image movement with connection can be obtained.
[0104]
In the above-described embodiment, each of the first and second directivity forming signal generation circuits 41 and 42 includes the same number of filter circuits as the number of the plurality of speaker units 21 of the array speaker 20. . The filter circuit is described as having both the delay adjustment function and the amplitude adjustment function. However, in order to form a beam-like directivity, it is sufficient that at least the delay time can be adjusted.
[0105]
When reproducing audio signals of the left and right channels in a speaker device using a conventional array speaker, always adjust not only the delay time but also the amplitude to suppress the level of the direct wave from the array speaker to the listener. In some cases, it may be necessary to adjust the frequency characteristics. However, in the speaker device according to the above-described embodiment, the direct sound from the array speaker 20 to the listener 12 is also actively used for sound reproduction. As a directivity of the beam sound waves BLref and BRref from the array speaker 20, there is no problem even if the side lobe at a small level is directed to the listener 12.
[0106]
Therefore, the circuits (filter circuits) constituting the first and second directivity forming signal generation circuits 411, 421 and 412, 422 may be those that can perform only the delay processing.
[0107]
However, as in the above-described example, a case where a filter circuit having a delay adjustment function and an amplitude adjustment function is used as a circuit configuring the first and second directivity forming signal generation circuits 411, 421 and 412, 422. As described above, the amplitude adjustment function enables the sound image localization position of the audio signal of each channel to be moved and adjusted in the left-right direction.
[0108]
Note that the amplitude adjustment function may be configured to use an attenuator provided on a signal path.
[0109]
By the way, in the above-described embodiment, the plurality of filter circuits constituting the first and second directivity forming signal generation circuits 411, 421 and 412, 422 correspond to the plurality of speaker units 21 of the array speaker 20 respectively. Therefore, various directivity controls can be performed.
[0110]
By utilizing this fact, for example, when the second channel signal generation circuit 42 generates a unit drive signal for the right channel as the unit drive signal U20, a beam-shaped beam for directly reaching the listener 12 is used. As shown in FIG. 7, the directivity of the sound wave BRdir is such that the direction of the main axis Ax of the directivity is slightly shifted to the right side of the direction of the center listener 12, thereby obtaining the sound of the right channel. It is possible to expand the service area where an appropriate localization feeling can be obtained.
[0111]
If the sound is shifted rightward from the center in a normal stereo system, the sound image is almost shifted to the right side, and a phenomenon that the left channel sound cannot be heard much may occur. This is due to the small service area.
[0112]
On the other hand, in the directivity characteristic of the direct wave BRdir as shown in FIG. 7, when the listener is listening at the position 12C in front of the array speaker 20, the sound of the right channel is The sound image is localized at an appropriate intermediate position.
[0113]
When the listener is listening at the position 12R shifted to the right side of the center, the level of the direct wave BRdir becomes larger than when listening at the center position 12C. The sound image is not pulled in the direction of arrival.
[0114]
Conversely, when the listener is listening at the position 12L shifted to the left from the center, the level of the direct wave BRdir is smaller than when listening at the center position 12C. The sense of localization is not impaired, and even in this case, the sound image can be localized in an appropriate direction. That is, the service area is expanded.
[0115]
Next, as shown in FIG. 6, the path lengths of the direct waves BLdir and BRdir are considerably shorter than the path lengths of the reflected waves BLref and BRref. In the above example, the direct waves BLdir and BRdir are delayed in the delay / amplitude adjustment circuits 413 and 423 in order to make the timings at which the direct waves BLdir and BRdir reach the listeners of the reflected waves BLref and BRref.
[0116]
However, in FIG. 6, when the equivalent sound source position of the direct waves BLdir and BRdir is, for example, at the center position Pr0 of the array speaker, that is, when the direct waves BLdir and BRdir are radiated from the center position Pr0, An unnatural sound field is formed, and an unnatural sound field feeling may be obtained particularly when the listener listens to the listener slightly shifted left and right from the front position.
[0117]
This problem can be solved if the equivalent sound source positions of the direct waves BLdir and BRdir are located away from the listener by the same length as the path lengths of the reflected waves BLref and BRref.
[0118]
To realize this, the filter coefficients of each set of the filter circuits 711 to 71n and 721 to 72n of the first directivity forming signal generation circuits 411 and 421 for obtaining the direct waves BLdir and BRdir from the array speaker 20 are set. May be adjusted to adjust the delay time for each unit drive signal so that the wavefronts of the direct waves BLdir and BRdir radiated from the array speaker 20 are closer to plane waves.
[0119]
Specifically, for the direct waves BLdir and BRdir, sound waves are output from the speaker units 21 almost simultaneously. That is, the delay times in the filter circuits of the first directivity forming signal generation circuits 411 and 421 are set to be substantially equal.
[0120]
In this way, as shown in FIG. 8, near the array speaker 20, the wavefronts of the direct waves BLdir and BRdir become almost plane waves. However, since the array speaker 20 has a finite size, the end of the array speaker 20 has an arc-shaped wavefront. Then, as the distance from the array speaker 20 increases, the wavefronts of the direct waves BLdir and BRdir gradually approach the wavefront on the spherical surface.
[0121]
As described above, by making the wavefronts of the direct waves BLdir and BRdir radiated from the array speaker 20 closer to a plane wave, the curvature of the sound wave surface at the listener position increases as shown in FIG. That is, since the equivalent sound source position 20D is located at a position deeper than the actual position of the array speaker 20, a more natural sound field feeling can be obtained.
[0122]
Depending on the position of the listener, the wavefront may be adjusted by adjusting the delay time of each filter circuit. For example, when it is desired to set the equivalent sound source position 20D at a deeper position, as shown in FIG. 9, the signal supplied to the speaker unit 21 in the center of the array speaker 20 is delayed more than the others, and The unit 21 may radiate the sound wave first, make the wavefront concave in the vicinity of the array speaker 20, and make the wavefront at the listener position more planar.
[0123]
[Other examples of sound reproduction method]
In the above example, the sound image based on the left and right two-channel audio signals is localized at desired positions on the left and right sides of the front wall surface 14F. However, it goes without saying that the present invention is not limited to this example.
[0124]
<First other example>
For example, a sound image based on a center channel audio signal can be localized as if it were behind a projection screen. FIG. 10 is a diagram for explaining the sound reproduction method in that case.
[0125]
In other words, in the case of this example, the unit drive signal for the center channel is generated using the center channel signal generation circuit having the same configuration as the first channel signal generation circuit 41 or 42. In the case of this example, the first directivity forming signal generation circuit generates a unit drive signal for forming a direct wave BCdir from the array speaker 20 to the listener 12, and generates the second directivity forming signal. The circuit generates a unit drive signal for forming a reflected wave BCref from the array speaker 20, which is once reflected by the ceiling 14 </ b> C of the listening room and reaches the listener 12.
[0126]
Then, in the same manner as described above, for the direct wave BCdir and the reflected wave BCref, the time of arrival at the listener and the level at the time of arrival at the listener are adjusted. Then, those two types of unit drive signals to be supplied to the same speaker unit 21 are combined and supplied to the corresponding speaker unit 21 to drive the array speaker 20.
[0127]
According to this example, in the same manner as described above, for the direct wave BCdir and the reflected wave BCref, by adjusting the time of arrival time at the listener and adjusting the level at the time of arrival at the listener, the sound of the center channel is obtained. The sound image based on the signal can be used as the virtual sound source position 20C on the back side of the projection screen 11.
[0128]
Also in the case of this example, by using the method described with reference to FIGS. 8 and 9, the sound image based on the audio signal of the center channel is localized at the virtual sound source position at a deeper position on the back side of the projection screen 11. The image projected on the projection screen and the virtual sound source position can be matched.
[0129]
Similarly, for example, the sound image can be localized at an intermediate position between the upper end of the projection screen 11 and the ceiling 14C.
[0130]
When the array speaker 20 is installed above the projection screen 11, the second beam-shaped sound wave is reflected on the floor surface 14G by adjusting the filter coefficient of the second directivity forming signal generation circuit. After that, it is sufficient to reach the listener.
[0131]
<Second other example>
Each of the above examples is a case where the reflected wave and the direct wave are combined and the sound image is localized in a desired direction. Instead of using the direct wave to the listener 12, the reflected wave in another direction is generated. It is also possible to localize the sound image in a desired direction by combining the two reflected waves.
[0132]
FIG. 11 is a diagram for explaining an example in that case. In this example, for example, the reflected wave BARref to the right wall surface 14R (similar to the reflected wave BRref in the above example) and the reflected wave BACref to the ceiling 14C (similar to the reflected wave BCref in the above first other example) And the sound image is localized as the virtual sound source position 20D on the upper right side of the projection screen 11.
[0133]
In the case of this example, the first directivity forming signal generation circuit is used to form a reflected wave BARref from the array speaker 20 after being reflected by the right wall surface 14R and then reaching the listener 12. A unit drive signal is generated, and the second directivity forming signal generation circuit forms a reflected wave BACref from the array speaker 20, which is once reflected by the ceiling 14 </ b> C of the listening room and then reaches the listener 12. For generating a unit drive signal.
[0134]
Then, in the same manner as described above, for the direct wave BARref and the reflected wave BACref, the time of arrival at the listener and the level at the time of arrival at the listener are adjusted. Then, those two types of unit drive signals to be supplied to the same speaker unit 21 are combined and supplied to the corresponding speaker unit 21 to drive the array speaker 20.
[0135]
[Other Modifications]
In the case of multi-channel surround reproduction, a method of synthesizing two sound waves as in the above-described embodiment may be applied to audio signals of all channels, The method of synthesizing two sound waves as in the above-described embodiment may be applied only to the audio signal of the channel of.
[0136]
In the above example, a video projector was used as the video playback device, so the projection screen was arranged above the array speaker. However, as the video playback device, a television monitor using a CRT (Cathode Ray Tube), A flat display device using an LCD (Liquid Crystal Display) or a PDP (Plasma Display Panel) may be used.
[0137]
When the projection screen 11 is a sound-transmitting projection screen (a projection screen having fine holes for sound transmission), an array speaker may be arranged behind the projection screen. . Of course, only an array speaker may be provided for music appreciation without providing a video playback device.
[0138]
Further, in the above example, the delay / amplitude adjustment circuits 413 and 423 are provided on the input side of the first directivity forming signal generation circuit, but may be provided on the output side. However, when provided on the output side, it is necessary to provide a delay / amplitude adjustment circuit for each speaker unit 21, and the amount of delay and amplitude are provided for all speaker units 21 constituting the array speaker 20. It is necessary to control a plurality of unit drive signals to be supplied in conjunction with each other so as to have similar values.
[0139]
Further, as described above, the delay / amplitude adjustment circuits 413 and 423 may have a configuration of a delay adjustment circuit having no amplitude adjustment function.
[0140]
Furthermore, in the above-described embodiment, the delay / amplitude adjustment circuit is provided for one of the first and second directivity forming signal generation circuits. It may be provided for both of the use signal generation circuits.
[0141]
In the above-described embodiment, the adjustment of the direction of the main axis of directivity of the first and second beam-shaped sound waves, the level thereof, and the delay time are performed by the adjustment operation units 44 and 45. However, the present invention is not limited to this. Instead, for example, the size (width, depth, height, etc.) of the listening room and the listening position are input, and the control circuit 43 calculates the parameters such as the above-described filter coefficients for the first and second beam sound waves. It may be.
[0142]
【The invention's effect】
As described above, according to the present invention, even when the sound wave radiated from the array speaker with the beam-like directivity reaches the listener after being reflected by the wall, the listener can Thus, the sound image can be localized in an appropriate sound image localization direction.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of a system configuration including an embodiment of a speaker device according to the present invention.
FIG. 2 is a diagram illustrating an example of a system configuration including an embodiment of a speaker device according to the present invention.
FIG. 3 is a diagram for explaining an example of an array speaker used in the embodiment of the speaker device according to the present invention.
FIG. 4 is a block diagram of an example of an array speaker audio signal generation circuit used in a speaker device according to an embodiment of the present invention;
FIG. 5 is a diagram illustrating a detailed circuit example of a part of the circuit in FIG. 4;
FIG. 6 is a diagram for explaining an example of a sound reproducing method used in the embodiment of the speaker device according to the present invention.
FIG. 7 is a diagram for explaining an example of a sound reproduction method used in the embodiment of the speaker device according to the present invention.
FIG. 8 is a diagram for explaining an example of a sound reproducing method used in the embodiment of the speaker device according to the present invention.
FIG. 9 is a diagram for explaining an example of a sound reproduction method used in the embodiment of the speaker device according to the present invention.
FIG. 10 is a diagram for explaining another example of the sound reproducing method used in the embodiment of the speaker device according to the present invention.
FIG. 11 is a diagram for explaining another example of the sound reproducing method used in the embodiment of the speaker device according to the present invention.
FIG. 12 is a diagram for explaining an example of a sound reproducing method by a conventional speaker device using an array speaker.
[Explanation of symbols]
Reference Signs List 20: array speaker, 21: speaker unit, 41: first channel audio signal generation circuit, 42: first channel audio signal generation circuit, 43: control circuit, 44: first channel adjustment operation section, 45: second Channel adjustment operation unit, 48: first channel audio input terminal, 49: second channel audio input terminal, 411, 421: first directivity forming signal generation circuit, 412, 422: second directivity formation Signal generation circuit, 413: delay / amplitude adjustment circuit

Claims (14)

An array speaker composed of a plurality of speaker units;
Receiving an input audio signal and generating a first plurality of unit drive signals to be supplied to the plurality of speaker units of the array speaker, wherein the first plurality of unit drive signals are the plurality of unit drive signals; A first directivity generating the first plurality of unit drive signals such that a direction of a main axis of directivity of sound waves emitted from the array speaker by being supplied to the speaker unit is set to a first direction; Forming signal generation means;
Receiving the input audio signal and generating a second plurality of unit drive signals to be supplied to the plurality of speaker units of the array speaker, wherein the second plurality of unit drive signals are the plurality of unit drive signals; The second plurality of unit drive signals so that the direction of the main axis of directivity of sound waves emitted from the array speaker by being supplied to the speaker unit is set to a second direction different from the first direction. Second directivity forming signal generating means for generating
At least one of an input side or an output side of the first directivity forming signal generating means or an input side or an output side of the second directivity forming signal generating means, and is provided from the array speaker to the first side. The time at which the sound wave radiated with the direction of the directional main axis reaches the listener, the time at which the sound wave radiated from the array speaker with the second direction as the direction of the directional main axis reaches the listener. Delay means for adjusting the difference between
A signal that supplies the first plurality of unit drive signals and the second plurality of unit drive signals time-adjusted by the delay unit to the same speaker unit, and synthesizes each of the speaker units. A speaker device characterized in that the speaker device is supplied to the speaker device. The speaker device according to claim 1,
The speaker device according to claim 1, wherein each of the first and second directivity forming signal generation units includes a plurality of delay adjustment units corresponding to at least the number of the plurality of speaker units. The speaker device according to claim 1,
A speaker device, wherein each of the first and second directivity forming signal generation units includes a plurality of delay and amplitude adjustment units corresponding to the number of the plurality of speaker units. The speaker device according to claim 1,
The delay means, the delay amount of the input signal is variable by the control signal,
A loudspeaker device, further comprising control means for generating the control signal for controlling a delay amount of the delay means. The speaker device according to claim 1,
The delay means, the delay amount and amplitude of the input signal is variable by the control signal,
The speaker device according to claim 1, further comprising control means for generating the control signal for controlling the delay amount and the amplitude in the delay means. The speaker device according to claim 1,
The first direction of the main axis of the directivity of the array speaker is a direction in which sound waves emitted from the array speaker directly reach the listener,
The second direction of the main axis of directivity of the array speaker is a direction in which sound waves emitted from the array speaker reach the listener after being reflected on a wall surface,
The speaker device according to claim 1, wherein the delay unit is provided before or after the first directivity forming signal generation unit. The speaker device according to claim 1,
The first direction of the main axis of the directivity of the sound wave emitted from the array speaker is a direction in which the sound wave emitted from the array speaker reaches the listener after being reflected on a wall surface,
The second direction of the main axis of the directivity of the sound wave radiated from the array speaker is a direction in which the sound wave radiated from the array speaker reaches a listener after being reflected on a wall surface different from the wall surface. Speaker device. The speaker device according to claim 1,
The first and second directivity forming signal generating means and the delay means are provided for each channel of the input audio signal of a plurality of channels,
A speaker device comprising: synthesizing signals supplied to the same speaker unit among the plurality of unit drive signals for each channel, and supplying the combined signals to the respective speaker units. The speaker device according to claim 6,
In the first directivity forming signal generation means, the first plurality of first directivity forming signals are arranged such that a direction of a main axis of a directivity of a sound wave in a direction directly reaching the listener is shifted from a listener position. Wherein the unit drive signal is formed. The speaker device according to claim 6,
In the first directivity forming signal generating means, a center of curvature of a wavefront of a sound wave in a direction directly reaching the listener is located farther from the listener than an actual arrangement position of the array speaker. , Wherein the first plurality of unit drive signals are formed. In a sound reproduction method for reproducing sound using an array speaker composed of a plurality of speaker units,
Generating, from an input audio signal, a first plurality of unit drive signals to be supplied to the plurality of speaker units of the array speaker, wherein the first plurality of unit drive signals correspond to the plurality of speaker units; The direction of the main axis of the directivity of the sound wave radiated from the array speaker by being supplied to one of the walls around the listener, so as to be in the direction of reaching the listener, the first plurality of A first directivity forming signal generating step of generating a unit drive signal of
Generating, from the input audio signal, a second plurality of unit drive signals to be supplied to the plurality of speaker units of the array speaker, wherein the second plurality of unit drive signals correspond to the plurality of speaker units; A second unit drive signal for generating the second plurality of unit drive signals so that the direction of the main axis of the directivity of the sound wave emitted from the array speaker by being supplied to the unit is the direction directly reaching the listener; A signal generation step for forming directivity of
The sound wave radiated from the array speaker with the first direction as the direction of the principal axis of directivity reaches the listener, and the sound wave is radiated from the array speaker as the direction of the principal axis of the directivity as the second direction. A delay step to adjust the difference between the time at which the sound waves reach the listener and
With
The first plurality of unit drive signals and the second plurality of unit drive signals time-adjusted in the delay step are combined with signals supplied to the same speaker unit and supplied to each speaker unit. And a sound reproducing method. In a sound reproduction method for reproducing sound using an array speaker composed of a plurality of speaker units,
Generating, from an input audio signal, a first plurality of unit drive signals to be supplied to the plurality of speaker units of the array speaker, wherein the first plurality of unit drive signals correspond to the plurality of speaker units; The direction of the main axis of the directivity of the sound wave radiated from the array speaker by being supplied to one of the walls around the listener, so as to be in the direction of reaching the listener, the first plurality of A first directivity forming signal generating step of generating a unit drive signal of
Generating, from the input audio signal, a second plurality of unit drive signals to be supplied to the plurality of speaker units of the array speaker, wherein the second plurality of unit drive signals correspond to the plurality of speaker units; The second pluralities are reflected so that the direction of the main axis of the directivity of the sound wave radiated from the array speaker by being supplied to the unit is reflected on a wall different from the wall and reaches the listener. A second directivity forming signal generating step of generating a unit drive signal of
The sound wave radiated from the array speaker with the first direction as the direction of the principal axis of directivity reaches the listener, and the sound wave is radiated from the array speaker as the direction of the principal axis of the directivity as the second direction. A delay step to adjust the difference between the time at which the sound waves reach the listener and
With
The first plurality of unit drive signals and the second plurality of unit drive signals time-adjusted in the delay step are combined with signals supplied to the same speaker unit and supplied to each speaker unit. And a sound reproducing method. In the sound reproducing method according to claim 11 or 12,
In each of the first and second directivity forming signal generation steps, at least an amount of delay with respect to the input audio signal is adjusted to generate the first and second plurality of unit drive signals. Sound reproduction method. In the sound reproducing method according to claim 11 or 12,
In each of the first and second directivity forming signal generation steps, the first and second plurality of unit drive signals are generated by adjusting a delay amount and an amplitude with respect to the input audio signal. Sound reproduction method.

Images