JP2001228867A - Performance sound field controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize natural sounds in musical instrument at performance, using a simple constitution. SOLUTION: A plurality of microphones 68 to 70 and a plurality of loud speakers 72 to 74 are disposed at an electronic musical instrument 62. The sound collection signals of the microphones 68 to 70 are successively changed over in routes by a sound collection signal changeover circuit 86, and reflected sound signals are formed in FIR filters 88 to 90. The reflected sound signals are added to the musical tone signals generated from a sound source generating circuit 79 by adders 96 to 98 and are reproduced from the loud speakers 72 to 74. The tones reproduced from the speakers 72 to 74 are reflected by the walls and ceilings of a room and are re-collected by the microphones 68 to 70.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a performance sound field control device for enhancing a sound field feeling such as a reverberation feeling and an expansive feeling when playing a musical instrument, and realizes a natural sound with a simple configuration. .

[0002]

2. Description of the Related Art As shown in FIG.
A sound source waveform is generated by a sound source generating circuit (tone generator) 2 and effect processing is appropriately performed (echo, reverberation, tremolo, etc.)
After that, the musical tone was radiated from the single or plural speakers 6 to the space via the power amplifier 4.

[0003] Conventionally, there has been an acoustic feedback (Acoustic Feedback) system whose principle is shown in Fig. 3 as a sound field support device for enhancing the reverberation and spaciousness of a room itself. This is a speaker 12 in the room 10
And the microphone 14 are arranged at an appropriate distance from each other, and the sound collected by the microphone 14 is transmitted through a head amplifier 16 to a FIR (Finite).
Impulse Response (non-cyclic type) is supplied to a filter 18 to generate a reverberation signal (mainly an early reflected sound signal), which is reproduced from a speaker 12 via a power amplifier 20 and collected by a microphone 14. By repeating this, the sense of volume (increase in sound pressure level), the increase in reverberation (extension of reverberation time), the sense of expansion (enhancement of side reflected sound energy), and the like are achieved. .

FIGS. 4 and 5 show a conventional sound field control device using the acoustic feedback system. FIG.
Shows the arrangement of microphones and speakers. In a room 22 such as a music room, four microphones 24 to 27 are installed on the ceiling, and four speakers 30 to 33 are installed on the wall. The device main body 36 for controlling the whole is configured as an independent device, and is installed in the room 22.

FIG. 5 shows a circuit configuration. The sound pickup signals of the microphones 24 to 27 are adjusted in frequency characteristics in order to prevent howling by an equalizer 42 through head amplifiers 38 to 41, and an FIR filter is used. 44, an initial reflected sound is generated, and amplified by the amplifiers 46-49,
~ 33. The ROM 52 stores initial reflected sound parameters of various sound field patterns. When a sound field pattern selection operation is performed by the external infrared remote controller transmitter 54, a corresponding sound field pattern selection signal 56 is transmitted and received by the light receiving window 58 of the apparatus main body 36. CPU6
0 receives this, reads out the initial reflected sound parameter of the corresponding sound field pattern from the ROM 52, sets it in the FIR filter 44, and sets the sound field space.

[0006]

In the electronic musical instrument shown in FIG. 2, since all effects are provided by electric signal processing except for some effects (such as a tremolo effect due to speaker rotation), the effects of adding echo and reverberation are not provided. Initially, there was a limit to providing a natural sound field effect. Also, since the effect is independent for each instrument, when playing with other instruments,
The added sound (especially reverberation) differs in quality, quantity, length, etc.
They lacked the sense of unity in their performances and disliked them.

The reverberation by the sound field support apparatus shown in FIGS. 4 and 5 requires speakers 30 to 33 exclusively for the reverberation, and microphones 24 to 33 on the wall and ceiling of the room 22.
27 and speakers 30 to 33,
Need to be installed independently, or signal cables must be routed inside the wall or ceiling, which increases the system size.
It was not easy to introduce.

An object of the present invention is to provide a performance sound field control device which solves the above-mentioned problems in the prior art and realizes a natural sounding sound field effect with a simple configuration.

[0009]

SUMMARY OF THE INVENTION The present invention combines an acoustic feedback system with an electronic musical instrument or the like. That is, the performance sound field control device according to the present invention is provided in a separate place, with a performance operation unit and a sound source generation unit that generates a tone signal in accordance with a performance operation performed by the performance operation unit or separately input performance information. A plurality of microphones each of which picks up a sound arriving from the surroundings, a reflected sound signal generation unit for respectively generating a reflected sound signal of a sound collection signal from the microphones, and a reflection generated by the reflected sound signal generation unit. Mixing means for mixing a tone signal generated by the sound source generating section into a sound signal, and a plurality of speakers which are installed at different locations and reproduce the signals output from the mixing means toward the surroundings, respectively. It is provided.

According to this, the same sound is given to the sound of the electronic musical instrument as well as the sound that enters the microphone from the outside. Therefore, when ensemble is performed between the electronic musical instrument and another electronic musical instrument or a natural musical instrument, the sound of all the musical instruments is given a similar sound, and a natural sound field effect can be provided. In addition, since the speaker for playback of the electronic musical instrument is also used as the speaker for the acoustic feedback system, the number of speakers can be reduced and the configuration can be simplified. In particular, if each component is incorporated in the electronic musical instrument main body, installation, movement, and the like become easy.

[0011] By repeatedly and successively switching the combination of connections between a plurality of microphones and a plurality of speakers, the transfer characteristics between the microphones and the speakers are averaged.
Reduction of coloration and expansion of howling margin are achieved. Thereby, even if the distance between the speaker and the microphone is fixed, coloration and howling hardly occur.

Further, the reflected sound signal generating section is constituted by an FIR filter, and the reflected sound parameter of the FIR filter is continuously and randomly varied on a time axis, whereby
The frequency characteristics of the FIR filter are flattened, and coloration and howling can be made more difficult to occur.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the performance sound field control device of the present invention is configured as an electronic piano will be described below. 6A and 6B show an arrangement example of a microphone and a speaker in an electronic piano, wherein FIG. 6A is a front view and FIG. 6B is a side view.
The electronic piano 62 is provided with a keyboard (performance operation unit) 64 at an intermediate height position on the front surface. The housing 6 of the electronic piano 62
6 (electronic musical instrument main body), three microphones 68 to 70 are embedded and installed with the sound receiving unit exposed to the outside. Of these, the microphones 68 and 69 are respectively disposed at positions above and below the keyboard 64 on the front of the housing 66 and separated to the left and right. Further, the microphone 70 is disposed at the left and right center positions of the top plate of the housing 66.

In the housing 66, three speakers 72 to 74 are buried and installed with their radiation surfaces exposed to the outside. Among them, the speaker 72 is disposed at the left and right center positions below the keyboard 64 on the front surface of the housing 66. The speakers 73 and 74 are provided at positions separated from the top plate of the housing 66 to the left and right. The signal cables of the microphones 68 to 70 and the speakers 72 to 74 are wired in the housing 66.

The musical tone played on the keyboard 64 is a speaker 72.
6 to 74, the reproduced musical sound and external sound are reflected by the wall surface or the ceiling surface of the room 76 and collected by the microphones 68 to 70 as shown in FIG.

FIG. 1 shows the configuration of a circuit section provided in the housing of the electronic piano 62. The portion of the signal line indicated by a thick line is a portion provided in a conventional electronic piano. In this circuit, three independent signal paths from three microphones 68 to 70 to three speakers 72 to 74 are configured in parallel. A tone generator 78 is a tone generator (tone generator) including a tone generator waveform generating, waveform shaping, effect processing circuit, and the like.
A tone signal is generated in accordance with performance information output from an IDI information generator 80 (for example, a magnetic disk device, an optical disk device, or the like that reproduces performance information for automatic performance). The tone signal is output with an effect such as an echo added as necessary.

The sound pickup signals of the microphones 68 to 70 are amplified by head amplifiers 82 to 84 and input to a sound pickup signal switching circuit 86. The sound pickup signal switching circuit 86 is for sequentially and repeatedly switching the combinations of the connections of the three inputs 1 to 3 and the three outputs 1 to 3 alternately.

FIG. 7 shows an example of the input / output switching operation by the sound pickup signal switching circuit 86. The sound pickup signal switching circuit 86 forms a kind of level matrix, and the input signals of the three systems are equally distributed to the outputs 1 to 3 of the three systems at a constant period while being alternately replaced. The gain changes continuously according to, for example, a sine curve, a triangular wave, or independent random signals satisfying the above conditions so that the sum of the gains of the three systems is kept constant at each time point. According to this, the same effect as when the three microphones 68 to 70 are sequentially and repeatedly switched between their installation positions is obtained, and the transfer characteristics are flattened by spatial averaging, and Reduction and the howling margin can be increased. The switching period is set to, for example, about 1 to 1/2 times the reverberation time of the room to be used.

The three output signals output from the outputs 1 to 3 of the pickup signal switching circuit 86 are output from FIR filters 88 to 9.
0, and a reflected sound signal is generated. F
The reflected sound parameters of the IR filters 88 to 90 are set to mutually different parameters, and are individually and continuously and randomly varied on the time axis and, if necessary, on the level axis as shown in FIG. . As a result, the disturbance of the frequency characteristics that occurs when the FIR filters 88 to 90 are of a fixed type is reduced, and the frequency characteristics are averaged, thereby further reducing the coloration and expanding the howling margin. The fluctuation of the time axis of the parameter is within a range that does not cause unnaturalness in hearing (for example, 0.25 msec to 5 msec).
This is realized by moving the output taps of the FIR filters 88 to 90 uncorrelatedly (with a variation width of msec). Also, as shown in FIG. 5, a plurality of types of reflected sound parameters may be stored in the ROM so that the player can arbitrarily select a desired reflected sound parameter and set it in the FIR filters 88 to 90. .

The reflected sound signals generated by the FIR filters 88 to 90 are input to equalizers 92 to 94, and are unique in frequency characteristics due to a room to be used, speakers 72 to 74, an installation place of the electronic piano 62, and the like. Roughly flatten the undulations. The characteristics of the equalizers 92 to 94 are such that the peak on the loop gain of each system is-
It is automatically adjusted for each frequency band so as to be 12 dB (of course, adjustment by the user is also possible).

The reflected sound signals output from the equalizers 92 to 94 are added and mixed with the tone signals output from the sound source generating circuit 78 by adders 96 to 98, amplified by the power amplifiers 100 to 102, and amplified by the speakers 72 to 94. Reproduced from 74. The sound reproduced from the speakers 72 to 74 is reflected on the wall surface or the ceiling surface of the room, collected by all the microphones 68 to 70, and passed again through each system.
4 is played back. This process occurs repeatedly in each system, and the reverberation is given and extended in a form fused with the original sound of the room.

The echo cancellers 104 to 112 correct the comb filter effect due to the direct feedback path formed between the speakers 72 to 74 and the microphones 68 to 70. That is, unlike the conventional acoustic feedback that is configured in the room itself, when the microphone and the speaker are arranged on the musical instrument itself, the physical distance between the sound source and the sound receiving point is small, so the sound radiated from the speaker is directly transmitted to the microphone. The number of paths to be fed back increases, and disturbance occurs on the frequency characteristics of the loop gain. Therefore, response F during this time
In order to cancel the comb filter effect by (ω), n
(The number of systems: n = 3 in the example of FIG. 1) square echo cancellers 104 to 112 are prepared, and the output signals of each system are added to adders 124 to 112 inserted before the sound pickup signal switching circuit 86.
126 and the microphones 68 through the speakers 72-74.
Cancels the sound returned directly to ~ 70. Thereby, howling can be more reliably prevented.

The characteristics of the echo cancellers 104 to 112 include, for example, a direct return path between the loudspeakers 72 to 74 and the microphones 68 to 70 and a return path corresponding to the primary reflected sound (in particular, the electronic piano 62 is placed near a window. Case), that is, the response is adjusted to be close to -F (ω) so as to cancel the initial part of the impulse response due to the acoustic feedback. The echo cancellers 104 to 11
2 can be configured with an adaptive filter to automatically adjust the characteristics. To adjust the echo cancellers 104 to 112, after the electronic piano 62 is installed in the room 76, impulse noise is generated from the sound source generation circuit 78 and the like, reproduced from the speakers 72 to 74, and collected by the microphones 68 to 70. Then, the impulse response is measured, and the parameters of the echo cancellers 104 to 112 are manually or automatically adjusted to approximately -F (ω) so as to cancel the initial part of the impulse response.

The adjustment of the equalizers 92 to 94 and the adjustment of the echo cancellers 104 to 112 are performed, for example, by automatically or manually adjusting the equalizers 92 to 94 at the beginning of the adjustment process, and then automatically or manually adjusting the echo cancellers 104 to 112. It can be done by adjusting. Further, while automatically or manually adjusting the echo canceller 104 (or after the adjustment), the equalizers 92 to 9 are adjusted.
4 can be finely adjusted (re-adjusted) automatically or manually.

According to the electronic piano 62 having the above configuration, a plurality of independent signal paths from the microphones 68 to 70 to the speakers 72 to 74 are formed. An averaging effect that cannot be obtained (addition in the squared sound pressure area) is obtained, and furthermore, the signal path is switched by the pickup signal switching circuit 86, and F
Time-varying processing of the reflected sound parameters in the IR filters 88 to 90 and the echo cancellers 104 to 112
The transfer characteristics between the microphones 68 to 70 and the speakers 72 to 74 are further largely averaged, so that reduction of coloration and expansion of a howling margin become remarkable.

In addition to the musical sound of the electronic piano 62 itself, the same sound is imparted to sounds entering the microphones 68 to 70 from the outside. Therefore, when ensemble is performed between the electronic piano 62 and another electronic musical instrument or natural musical instrument, all the sounds are used. A similar sound is given to the sound of the musical instrument, and a natural sound field effect can be given. In addition, the playback speaker 72 of the electronic piano 62
Since 74 is also used as the acoustic feedback system speaker, the number of speakers can be reduced, and the configuration can be simplified. In addition, since each component is built into the housing 66 of the electronic piano 62 and is integrally incorporated, installation, movement, and the like become easy.

As shown by the dotted line in FIG. 1, ensemble signals from other musical instruments can be directly input to each system by adders 120 to 122. Further, in the above embodiment, the number of systems is set to three, but may be set to other numbers. In the above embodiment, the case where the present invention is applied to an electronic piano has been described. However, the present invention can be applied to other electronic keyboard musical instruments and electronic musical instruments other than the keyboard musical instruments.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, and is a block diagram of a circuit unit provided in a housing of the electronic piano of FIG. 6;

FIG. 2 is a block diagram showing a tone generation system of a conventional electronic musical instrument.

FIG. 3 is a principle diagram of acoustic feedback.

FIG. 4 is a layout diagram showing a conventional introduction sequence of acoustic feedback.

FIG. 5 is a block diagram showing a circuit configuration of acoustic feedback of FIG. 4;

6A and 6B are a front view and a side view showing an arrangement example of microphones and speakers when the present invention is applied to an electronic piano.

FIG. 7 is an operation explanatory diagram of the sound pickup signal switching circuit 86 of FIG. 1;

8 is a diagram showing a reflected sound parameter of the FIR filter of FIG. 1 and a time-varying operation of a time axis and a level axis thereof.

[Explanation of symbols]

62: electronic piano (performance sound field control device), 64: keyboard (performance operation unit), 66: housing (electronic musical instrument main body), 68,
69, 70 ... microphone, 72, 73, 74 ... speaker, 7
8 sound source generating circuit (sound generating unit), 86 sound pickup signal switching circuit (signal switching means), 88, 89, 90 FIR filters (reflected sound signal generating means), 96, 97, 98 ... adders (mixing) Means), 104-112 ... Echo canceller.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04S 7/00 G10K 15/00 B

Claims (4)

[Claims] 1. A performance operation unit, a sound source generation unit that generates a tone signal in accordance with a performance operation performed by the performance operation unit or separately input performance information; A plurality of microphones each of which picks up a sound, a reflected sound signal generating unit that respectively generates a reflected sound signal of a sound collected signal by these microphones, and a reflected sound signal generated by the reflected sound signal generating unit, and the sound source generating unit A sound field comprising mixing means for mixing the tone signals generated in step (a), and a plurality of speakers installed at separate locations and reproducing the signals output from the mixing means toward the surroundings, respectively. Control device. 2. A signal path switching means for sequentially and repeatedly switching a combination of connections between the plurality of microphones and the plurality of speakers in a signal path from the plurality of microphones to each of the mixing means. The performance sound field control device according to claim 1, further comprising: 3. An FIR system wherein said reflected sound signal generating section varies a reflected sound parameter continuously and randomly on a time axis.
3. The performance sound field control device according to claim 1, wherein the control device comprises a filter. 4. The performance sound field control device according to claim 1, wherein each of the components is integrated into an electronic musical instrument main body.