JP2572563Y2 - Asymmetric sound field correction device - Google Patents

Description

[Detailed description of the invention] Overview In providing two listening positions, left and right, between a left speaker and a right speaker, such as in a vehicle cabin, a center speaker is provided between the left speaker and the right speaker. Provide. The stereo sound signal from the sound signal source is output to the left and right speakers as the sound signal of the fundamental sound, and the sound signals of the fundamental sounds of both the left and right channels are arithmetically processed to obtain an initial reflection sound, a reverberation sound, and the like. The sound signal of the sound effect is created for each of the left and right channels, and is output to the left speaker and the right speaker, respectively. Further, a signal obtained by correcting and adding at least one of the phase and the level of the sound signal of the fundamental sound and a signal obtained by correcting and adding at least one of the phase and the level of the sound signal of the sound effect are added. To the center speaker.

In this way, a left-right symmetric sound field in which the sound image is localized in the front direction by the fundamental sound is formed at each of the left and right listening positions, and the sound field is expanded by the sound effect.

The present invention relates to an asymmetric sound field for correcting asymmetry of a sound field generated when a stereophonic signal is reproduced by a speaker arranged asymmetrically from a listener, such as in a vehicle cabin. The present invention relates to a correction device.

FIG. 6 is a plan view for explaining a conventional technique.
In the conventional on-vehicle sound reproducing device, as shown in FIG. 6A, a channel speaker sr is disposed in the vehicle compartment 51 at the right front of the driver's seat 52 and at the left front of the passenger seat 53. A channel speaker sl is arranged. These speakers sl and sr are mounted, for example, in the instrument panel 54.

Therefore, focusing on the driver 55, the speakers sl, sr
When the sound of the same energy level is emitted from the speaker 55, the sound energy distribution in the sense of hearing of the driver 55 does not become uniform between the left and right speakers sl and sr as shown in FIG. It will be biased toward the speaker sr closer to the driver 55.

For this reason, the localization position of the virtual sound source, which should be originally located in the front direction of the driver 55 indicated by the reference numeral l51, is shifted to the speaker sr side as shown by the reference numeral 57. A similar problem also occurs in the passenger seat 53.

In the limited room 51, speakers sl and sr
Due to restrictions on the mounting position of the device, the spread angle indicated by the reference numeral 51 becomes smaller than 30 degrees at which an ideal sound field can be formed.

Thus, the conventional on-vehicle sound reproducing apparatus has a problem that the localization direction of the sound image is shifted and an asymmetric sound field is formed, and it is not possible to perform sound reproduction with a sense of realism. .

SUMMARY OF THE INVENTION An object of the present invention is to provide an asymmetric sound field correction device capable of forming a symmetrical sound field having a wide spread and capable of performing realistic sound reproduction.

Means for Solving the Problems The present invention is characterized in that a right speaker and a left speaker are arranged at an interval from each other, and a center speaker is arranged near the center of the right speaker and the left speaker. A first listening position facing the left speaker and the center speaker and provided between the right speaker and the center speaker; and a first listening position facing the right speaker, the left speaker and the center speaker, and between the left speaker and the center speaker. A stereo sound reproducing device to be listened to at a second listening position provided, wherein an acoustic signal of outputting a fundamental sound of a left channel to the left speaker and outputting an acoustic signal of a fundamental sound of the right channel to the right speaker. A sound signal of a fundamental sound of both the left and right channels from the sound signal source, and at least one of a phase and a level of the sound signal. Basic sound adjusting means for correcting and adding one of them, outputting the sound to the center speaker, and processing the sound signal of the fundamental sound of both the left and right channels from the sound signal source to obtain the sound of the sound effect of each of the left and right channels. A sound effect generating means for generating a signal and outputting the signal to the left and right speakers, and an audio signal of the sound effect of both the left and right channels is provided, and at least one of the phase and the level of the audio signal is corrected and added. And a sound effect adjusting means for outputting to the center speaker. In the first listening position and the second listening position,
The spread value of the sound effect is selected to be greater than the spread angle of the basic sound, and the spread value of the basic sound is formed within the spread angle of the sound effect. An asymmetric sound field correction device, wherein the correction in the sound effect adjusting means is set respectively.

Also, in the present invention, the basic sound adjusting means includes a phase level correcting means for performing phase correction and level correction to the sound signal of the basic sound of each of the left and right channels, and an acoustic signal of the basic sound of both the left and right channels. Addition level correction means for level correction, and addition phase correction means for adding the sound signal from the left and right phase level correction means and the sound signal from the addition level correction means to correct the phase and providing the corrected sound to the center speaker. And characterized in that:

Also, in the present invention, the sound effect adjusting means includes a phase level correction means for performing phase correction and level correction respectively to the sound signal of the left and right channel sound effects, and an audio signal of the right and left channel sound effects. Addition level correction means for level correction, and addition phase correction means for adding the sound signal from the left and right phase level correction means and the sound signal from the addition level correction means to correct the phase and providing the corrected sound to the center speaker. And characterized in that:

(Operation) According to the present invention, when the left speaker and the right speaker performing stereo sound reproduction have different directions from the listening position, such as in a passenger compartment of a car, the left speaker and the right speaker are not connected to each other. A center speaker is provided near the center position. A stereo sound signal from a sound signal source is given to each of the left and right speakers as a sound signal of a fundamental sound. The sound signals of the basic sounds of both the left and right channels are added to the basic sound adjusting means after at least one of the phase and the level is corrected and added to the center speaker.

Therefore, by adjusting the correction amounts of the phase and the level, it is possible to form left and right symmetric sound fields with the localization direction of the sound image of the fundamental sound at the two left and right listening positions being the front direction.

Based on the sound signal of the basic sound, sound effect creating means creates an acoustic signal of an effect sound such as an initial reflected sound or a reverberant sound for each of the left and right channels, and outputs the signals to the left and right speakers, respectively. The sound signals of the sound effects of both the left and right channels are added to the center speaker after the at least one of the phase and the level has been corrected by the sound effect adjusting means.

The correction amounts of the phase and the level in the sound effect adjusting means are different from the correction amounts in the basic sound adjusting means, and the sound field of the sound effect is wider than the sound field of the basic sound at the first and second listening positions. The values are chosen as follows.

In this way, at the right and left first and second listening positions, the sound field of the fundamental sound is formed symmetrically, and the sound field of the sound effect is made wider than the sound field of the fundamental sound to produce a realistic sound field. Perform sound reproduction with a feeling.

Embodiment FIG. 1 shows an on-vehicle sound reproducing apparatus 1 according to an embodiment of the present invention.
FIG. 2 is a block diagram showing an electrical configuration of the embodiment. Car cabin 2
Inside, an instrument panel 5 arranged in front of a driver seat 3 and a passenger seat 4 includes speakers SL, SC,
SR is provided. That is, a speaker SL is provided on the left side facing the driver's seat 3 and the passenger seat 4, a speaker SR is provided on the right side, and a center speaker SC is provided near the center. The driver's seat 3 is provided between the right speaker SR and the center speaker SC. The passenger seat 4 is provided between the left speaker SL and the center speaker SC.

Acoustic signal sources such as magnetic tape players and radio receivers
From 11, the acoustic signal of the fundamental sound of the left channel is derived on line 12, and the acoustic signal of the fundamental sound of the right channel is derived on line 13. The sound signals of these two channels are supplied to a plurality (three in this embodiment) of sound image control circuits U1 as basic sound adjusting means.
~ U3 has been entered.

In general, the sound propagation characteristics differ depending on the frequency. For this reason, the phases of all the frequency bands of the sound heard near the entrance of the ear canal of the listeners 3a and 4a sitting in the driver's seat 3 and the passenger's seat 4 and the like are changed. In order to align the sound signals, the sound image control circuits U1 to U3 are provided for each predetermined frequency band.
Is corrected by

Accordingly, the sound signal of the fundamental sound of the left channel input to the sound image control circuit U1 via the line 12 is input to a bandpass filter (hereinafter, abbreviated as BPF) F1L, and the sound image control circuit U1 A signal component in a frequency band 1 for performing sound image control, for example, 200 to 400 Hz is waved. BPFF
The 1L output is input to an adder ML and also to a crosstalk generation circuit C1 described later. Similarly, the line
The sound signal of the fundamental sound of the right channel derived to 13 is BPFF
After the signal component of the frequency band 1 is waved at 1R, it is input to the adder MR and the crosstalk generation circuit C1.

Similarly, in the sound image control circuit U2, the sound signal of the fundamental sound of the left channel is subjected to a frequency band 2, for example, a signal component of 400 to 800 Hz by the BPFF2L, and then the adder ML
The sound signal of the fundamental sound of the right channel, which is input to the crosstalk generation circuit C2, is passed through the BPFF2R to the adder MR.
And input to the crosstalk generating circuit C2.

Furthermore, in the sound image control circuit U3, the sound signal of the fundamental sound of the left channel is BPFF3L in frequency band 3, for example,
After the signal component of 800 to 1600 Hz is waved, the adder ML
The sound signal of the fundamental sound of the right channel, which is input to the crosstalk generation circuit C3, is passed through the BPFF3R to the adder MR.
And input to the crosstalk generation circuit C3.

A part of the sound signal of the fundamental sound of the left channel derived to the line 12 is added to the adder ML via a high-pass filter (hereinafter abbreviated as HPF) F4L or a low-pass filter (hereinafter abbreviated as LPF) F5L. Is input to Similarly, a part of the acoustic signal of the fundamental sound of the right channel derived on the line 13 is input to the adder MR via HPFF4R or LPFF5R. For example, the cutoff frequency 4 of HPFF4L and F4R is 1600
Hz, and the cutoff frequency 5 of LPFF5L, F5R is selected to be 200 Hz.

FIG. 2 (1) is a block diagram showing a specific configuration of the crosstalk generation circuit C1. This crosstalk generation circuit
In C1, the outputs of the BPFF1L and F1R
The signal is input to the adder M1 via the PL and PR and the attenuators AL and AR. The phase shifters PL and PR correct the phases of the input audio signals by θL and θR, respectively, and the attenuators AL and AR attenuate the input audio signals by aL and aR.

In this crosstalk generating circuit C1, the sound signals of the fundamental sounds of the left and right channels are added by an adder M2, further attenuated by an attenuator AC at an attenuation rate aC, and then input to the adder M1. . The output of the adder N1 is output to the adder MC after the phase is corrected by φ in the phase shifter PC.

On the other hand, the stereo sound signal of the fundamental sound from the acoustic signal source 11 is also input to the sound effect creating circuit 17, and this sound effect creating circuit 17 is based on the sound signal of the fundamental sound,
It creates sound effects such as early reflections and reverberation for each of the left and right channels and outputs them to lines 14 and 15. Note that a configuration for sound image control is provided for the sound signal of the sound effect from the sound effect creation circuit 17 as well as the sound signal of the basic sound from the sound signal source 11. In the structure, reference numerals corresponding to the structure of the above-described sound signal of the basic sound are indicated with a suffix a, and the description thereof is omitted.

However, as shown in FIG. 2 (2), the phase correction amounts θLa, θR in the phase shifters PLa, PRa, PCa of the crosstalk generating circuit C1a used in the sound image control circuit U1a as the sound effect adjusting means.
a, φa and the attenuation rate aLa, aR in the attenuators ALa, ARa, ACa
In this embodiment, a and aCa are set to values different from the phase correction amounts θL, θR, φ and the attenuation factors aL, aR, aC in the crosstalk generation circuit C1, respectively.

The crosstalk generation circuits C2 and C3 are configured in the same manner as the crosstalk generation circuit C1, and
a and C3a are configured similarly to the crosstalk generation circuit C1a.

The sound signal from the adder ML is supplied to the speaker SL after being amplified by the power amplifier AMPL. Similarly, the sound signals from the adders MR and MC are respectively supplied to the power amplifiers AMPR and
The signals are given to the speakers SR and SC via the AMPC.

FIG. 3 is a plan view for explaining functions of the sound image control circuits U1 to U3. For the listener 3a in the driver's seat 3, the speaker SR is disposed at a position forming a direction angle θ11, the speaker SC is disposed at a position forming a direction angle θ12 larger than the direction angle θ11, and the speaker SL is disposed at a position forming the direction angle θ12. It is arranged at a position forming a direction angle θ13 larger than θ12. Now, Fig. 3 (1)
When the sound is emitted only from the speaker SR as shown by, the listener 3a perceives the sound source direction in the direction of the reference numeral 1.

On the other hand, when the same sound is emitted from the speaker SC together with the sound of the right channel from the speaker SR,
As shown in FIG. 3 (2), the listener 3a perceives the direction of the sound source substantially forward as indicated by the reference numeral l2.

Therefore, the phase shifters of the crosstalk generating circuits C1 to C3
By converting the phase of the audio signal by θR by PR and further converting the level by aR, the listener 3a can perceive the right channel sound source direction perceived by the speaker SR indicated by the reference numeral l2. Can be perceived outside the speaker SR, as indicated by reference numeral 13 in FIG. 3 (3).

However, in this state, the sound of the left channel is emitted from the speaker SC via the phase shifter PL, and the speaker BP is also emitted from the speaker SL.
When the sound of the left channel is emitted through FF1L to F3L, the localization direction of the sound image to be localized in the front direction of the listener 3a indicated by reference numeral 14 in FIGS. 3 (3) and 4 (1) also becomes The position shifts to the speaker SR as indicated by reference numeral 15. This is because the energy distribution of the sound heard at the listening position of the listener 3a is indicated by the reference numeral in FIG.
This is because, as shown by 11, the peak distribution can be set in front of the listener 3a indicated by the reference numeral 14, but the left and right energy distributions become asymmetric.

Therefore, by correcting the phase φ by the phase shifter PC, the sound energy distribution can be made bilaterally symmetric as indicated by reference numeral 12 in FIG. 4 (2). Accordingly, as shown in FIG. 3 (4) and FIG. 4 (1), the localization direction of the sound image is set to the front direction of the listener 3a indicated by the reference numeral l4, and further indicated by the reference numerals l6 and l7. As a result, a symmetrical sound field having a divergence angle θ3 from the front direction can be formed. Note that this spread angle θ3
Can form an ideal sound field, for example, 30
The phases θR and φ are adjusted so as to be on the order of degrees.

Similarly, the listener 4a in the passenger seat 4 can form a symmetrical sound field by adjusting the phases θL and φ of the phase shifters PL and PC. Furthermore, similarly for the sound effect, by adjusting the phase correction amounts θLa, θRa, φa and the attenuation factors aLa, aRa, aCa in the crosstalk generation circuits C1a to C3a in the sound image control circuits U1a to U3a, similarly. A symmetrical sound field can be formed. As shown in FIG. 5, with respect to this sound effect, the spread angle θ22 of the basic sound is set to be wider than the spread angle θ21 of the basic sound, and the spread angle θ21 of the basic sound is set to the spread angle θ22 of the sound effect. , The phase correction amounts θLa, θRa, φa and the attenuation rate aL
a, aRa, and aCa are adjusted.

The center speaker SC is arranged near the center between the right speaker SR and the left speaker SL. The listener 3a of the driver's seat 3 is provided between the speakers SR, SC and the speakers SR, SC, SL. The listener 4a of the passenger seat 4 is provided between the speakers SL and SC, facing the speakers SR, SC and SL.

Thus, in this embodiment, the driver's seat 3 and the passenger's seat 4
Form a sound field of a symmetrical fundamental sound indicated by reference signs JR and JL, respectively, whereby in front of the listeners 3a and 4a,
The sound image can be localized without play. The sound field of the sound effect indicated by reference characters JRa and JLa is formed wider than the sound fields JR and JL of the basic sound. In this manner, the sound fields JR and JL of the basic sound and the sound fields JRa and Jla of the sound effect are individually controlled in the cabin 2 where there are many restrictions on the mounting positions of the speakers SL and SR. Thus, it is possible to localize the sound image in front of the listeners 3a and 4a, and to form a sound field having a spread.

In addition, the present invention can be widely applied to home use, business use, and the like, as well as to in-vehicle use.

Effects of the Invention As described above, according to the present invention, a center speaker is provided near the center of the left and right speakers, and the left and right speakers have the sound of the fundamental sound of the left and right channels from the sound signal source. Signal and the sound signal of the sound effect of each of the left and right channels created based on the sound signal of the basic sound, and the sound signal of the basic sound and the sound effect of both the left and right channels is sent to the center speaker. Since at least one of the sound level and the level is adjusted and then added, the spread of the sound field of the basic sound and the spread of the sound field of the sound effect can be individually adjusted at the left and right listening positions.

Therefore, the sound field of the fundamental sound is formed so that the sound image is localized in the front direction, and the sound field of the sound effect is formed wider than the sound field of the fundamental sound, so that the sound field is symmetrical and left-right. An extended sound field can be formed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electric configuration of an on-vehicle sound reproducing apparatus 1 according to an embodiment of the present invention, FIG. 2 is a block diagram showing a specific configuration of crosstalk generating circuits C1 and C1a, and FIG. 4 is a plan view for explaining the functions of the sound image control circuits U1 to U3, FIG.
FIG. 5 is a distribution diagram of acoustic energy for explaining an asymmetric sound field. FIG. 5 is a plan view showing the spread between the sound fields JL and JR of the fundamental sound and the sound fields JLa and JRa of the sound effect according to the present invention. FIG. 1 is a plan view for explaining a conventional technique. DESCRIPTION OF SYMBOLS 1 ... In-vehicle sound reproduction apparatus, 2 ... Cab, 3 ... Driver seat, 4 ...
Passenger seat, 3a, 4a: listener, 11: sound signal source, 17: sound effect creation circuit, AL, AR, AC; ALa, ARa, ACa: attenuator, C1 to C3; C1a
~ C3a… Crosstalk generation circuit, PL, PR, PC; PLa, PRa, PCa
… Phase shifter, SL, SR, SC… Speaker, U1-U3… Sound image control circuit

Claims (3)

(57) [Scope of request for utility model registration] 1. A right speaker, a left speaker, and a center speaker, wherein a right speaker and a left speaker are arranged at an interval from each other, and a center speaker is arranged near a center of the right speaker and the left speaker. A first listening position provided between the right speaker and the center speaker, and a second listening position provided opposite the right speaker, the left speaker, and the center speaker, and provided between the left speaker and the center speaker. A sound signal source for outputting a left-channel fundamental sound signal to the left speaker and outputting a right-channel fundamental sound signal to the right speaker; and a sound signal source. The sound signal of the fundamental sound of both the left and right channels is given, and at least one of the phase and level of the sound signal is corrected and added. A basic sound adjusting means for outputting to the center speaker, and a sound signal of a basic sound of both the left and right channels from the acoustic signal source is arithmetically processed to create sound signals of sound effects of the left and right channels, and Sound effect creating means for outputting to the right speaker, and sound signals of sound effects of both the left and right channels are provided, and at least one of the phase and the level of the sound signal is corrected and added, and output to the center speaker. And a spread angle of the sound effect is selected to be larger than a spread angle of the basic sound at the first listening position and the second listening position, and the spread angle of the basic sound is effective. A correction value in the basic sound adjustment means and a correction value in the sound effect adjustment means are respectively set so as to be formed within a sound spread angle. Symmetric sound field correction device. 2. The basic sound adjusting means includes: phase sound level correcting means for performing phase correction and level correction to the sound signal of the fundamental sound of each of the left and right channels; and sound signal of the fundamental sound of both the left and right channels. Addition level correction means for level correction, and addition phase correction means for adding the sound signal from the left and right phase level correction means and the sound signal from the addition level correction means to correct the phase and providing the corrected sound to the center speaker. The asymmetric sound field correction device according to claim 1, comprising: 3. The sound effect adjusting means adds phase sound level correcting means for performing phase correction and level correction to the sound signal of each of the left and right channels, and adds the sound signal of the sound effect of each of the left and right channels. Addition level correction means for level correction, and addition phase correction means for adding the sound signal from the left and right phase level correction means and the sound signal from the addition level correction means to correct the phase and providing the corrected sound to the center speaker. The asymmetric sound field correction device according to claim 1 or 2, further comprising: