JP2572564Y2 - Asymmetric sound field correction device - Google Patents

Description

[Detailed description of the invention] Outline In correcting the asymmetric sound field at the listening position where the directional angle of the left speaker and the directional angle of the right speaker are different from each other, such as in the interior of a car, 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 in which at least one of the phase and the level of the sound signal of the fundamental sound of the left channel is corrected,
A signal obtained by correcting at least one of the phase and the level of the sound signal of the sound effect of the left channel is given to the right speaker, and the phase and level of the sound signal of the fundamental sound and the sound signal of the sound effect of the right channel are similarly given. A signal corrected for at least one of them is provided to the left speaker.

Thus, a symmetrical sound field in which the sound image is localized in the front direction by the fundamental sound is formed at listening positions where the directional angles of the left and right speakers are different from each other, and the sound field is formed by the sound effect. To have a spread.

The present invention relates to an asymmetric sound field which corrects the asymmetry of a sound field generated when a stereo sound signal is reproduced by speakers arranged asymmetrically from a listening position, such as in a vehicle cabin. The present invention relates to a correction device.

2. Description of the Related Art FIG. 5 is a plan view for explaining an asymmetric sound field formed in a vehicle interior 51. In the in-vehicle sound reproduction device, the fifth
As shown in FIG. 1A, in the passenger compartment 51, the driver's seat 52
The right channel speaker sr is located on the right front of the passenger seat.
A left-channel speaker sl is disposed in front of the left side of 53. These speakers sl and sr are mounted in the instrument panel 54, for example.

In a typical prior art, the loudspeakers sl and sr are provided with an audio signal from an audio signal source while adjusting only the left / right balance, that is, the level.

Therefore, focusing on the driver 55, the speakers sl, sr
When the sound of the same energy level is emitted from the speaker 55, as shown in FIG. 5 (2), 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. 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. Even if the balance is adjusted, the localization position of the sound image is shifted to the speaker sr due to the phase difference between the left and right sounds caused by the difference in the sound propagation distance.

Furthermore, in the passenger compartment 51, which is a limited acoustic space, the reference sign θ5 is used due to restrictions on the mounting positions of the speakers sl and sr.
The divergence angle indicated by 1 is smaller than 30 degrees at which an ideal sound field can be formed.

Thus, in the vehicle-mounted sound reproducing apparatus of the related art, the localization direction of the sound image is deviated to form an asymmetric sound field, and it is not possible to perform realistic sound reproduction. is there.

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 In the present invention, a right speaker and a left speaker are arranged at an interval from each other, are opposed to the right speaker and the left speaker, and are located between the right speaker and the left speaker. At a listening position provided near a right speaker or a left speaker, in a stereo sound reproducing device to be listened, an acoustic signal of a fundamental sound of a left channel is output to the left speaker, and an acoustic signal of a fundamental sound of the right channel is outputted to the right speaker. An audio signal source to be output, and an audio signal of the fundamental sound of both the left and right channels from the audio signal source are given, and at least one of the phase and level of the audio signal of the left channel is corrected and output to the right speaker, Basic sound adjusting means for correcting at least one of the phase and the level of the sound signal of the right channel and outputting the corrected sound signal to the left speaker; The sound signal of the fundamental sound of both the left and right channels from the CPU is processed to create the sound signal of the sound effect of each of the left and right channels, and the sound effect creating means for outputting the sound signal to the left and right speakers, respectively. A sound signal of a sound is given, and at least one of the phase and level of the sound signal of the left channel is corrected and output to the right speaker, and at least one of the phase and level of the sound signal of the right channel is corrected. And a sound effect adjusting means for outputting the sound effect to the left speaker, wherein at the listening position, the spread angle of the sound effect is selected to be larger than the spread angle of the basic sound, and the spread angle of the basic sound is the sound effect. The correction value in the basic sound adjustment means and the correction value in the sound effect adjustment means are set so as to be formed within the divergent angle. It is asymmetric sound field correction device.

According to the present invention, the left speaker and the right speaker for reproducing the stereo sound are provided at positions different from each other in the direction angle from the listening position, such as in the cabin of an automobile. 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.

Further, in the basic sound adjusting means, the sound signal of the basic sound of the left channel is provided to the right speaker after at least one of the phase and the level has been corrected,
The sound signal of the fundamental sound of the right channel is given to the left speaker after performing the same correction.

Therefore, by adjusting the correction amount of the phase and the level, a symmetrical sound field can be formed with the localization direction of the sound image of the fundamental sound at the listening position as 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. Further, in the sound effect adjusting means, like the sound signal of the basic sound, the sound signal of the sound effect of the left channel, after at least one of the phase and the level is corrected, is given to the right speaker, The same correction is performed on the sound signal of the sound effect of the right channel.

The correction amount of the phase and the level in the sound effect adjusting means is different from the correction amount in the basic sound adjusting means, and is selected at a listening position so that the sound field of the sound effect is wider than the sound field of the basic sound. Have been.

In this way, at the listening position where the directional angles of the left and right speakers are different from each other, 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. 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 disposed in front of a driver's seat 3 and a passenger seat 4 includes speakers SL and SR.
Is provided. That is, the driver's seat 3 and the passenger's seat 4
, A speaker SL is provided on the left side, and a speaker SR is provided on the right side. The driver's seat 3 and the passenger's seat 4 are provided between the right speaker SR and the left speaker SL, and are provided near the right speaker SR and the left speaker SL, respectively.

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, sound propagation characteristics vary depending on the frequency. Therefore, in order to align the phases of all frequency bands of sound to be heard near the entrance of the ear canal of the listener 3a sitting in the driver's seat 3, the sound signal is Are corrected by the sound image control circuits U1 to U3 for each predetermined frequency band.

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 Frequency band f1, where sound image control should be performed,
For example, a signal component of 200 to 400 Hz is waved. The output of BPFF1L is input to an adder ML and also to a crosstalk generation circuit C1 described later. Similarly, the sound signal of the fundamental sound of the right channel derived to the line 13 is added to the adder MR after the signal component of the frequency band f1 is waved by the BPFF1R.
And input to 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 a frequency band f2 in BPFF2L, for example,
After the signal component of 400 to 800 Hz is waved, the signal is input to the adder ML and the crosstalk generation circuit C2, and the sound signal of the fundamental sound of the right channel is passed through the BPFF2R to the adder MR and the crosstalk generation circuit. Input to C2.

Further, in the sound image control circuit U3, the sound signal of the fundamental sound of the left channel is frequency band f3 in BPFF3L, for example, 80
After the signal component of 0 to 1600 Hz is waved, the signal is input to the adder ML and the crosstalk generation circuit C3, and the sound signal of the fundamental sound of the right channel is passed through the BPFF3R to the adder MR and the crosstalk generation circuit. Input to 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 f4 of HPFF4L, F4R is 1600 Hz
And the cutoff frequency f5 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, a part of the output of the BPFF1L is input to the adder M1 via the attenuator AL, added to the output from the BPFF1R, and output to the adder MR.

On the other hand, a part of the output of the BPFF1R is input to the adder M2 via the attenuator AR and the phase shifter PR, added to the output from the BPFF1L, and then output to the adder ML.
The phase shifter PR corrects the phase of the input sound signal by θR,
The attenuators AL and AR attenuate the input sound signal by aL and aR.

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 the sound effect creating circuit 17 separates each left and right channel based on the acoustic signal of the fundamental sound. Creates sound effects such as early reflections and reverberation, and outputs them to lines 14 and 15. It should be noted that, for the sound signal of the sound effect from the sound effect creation circuit 17, similarly to the sound signal of the basic sound from the sound signal source 11, a configuration for sound image correction is provided. 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), in the crosstalk generating circuit C1a used in the sound image control circuit U1a as the sound effect adjusting means, part of the output of BPFF1Ra is transmitted from the attenuator ARa via the phase shifter PRa. Is input to the adder M2a. Further, the phase correction amounts θLa and θRa in the phase shifters PLa and PRa and the attenuation factors aLa and aRa in the attenuators ALa and ARa are mutually reciprocal with the phase correction amounts θR and the attenuation factors aL and aR in the crosstalk generating circuit C1, respectively. In this embodiment, different values are set.

The crosstalk generating circuits C2 and C3 are configured in the same manner as the crosstalk generating circuit C1, and the crosstalk generating circuits C2a and C3
“a” is 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 acoustic signal from the adder MR is provided to the speaker SR via the power amplifier AMPR.

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, and the speaker SL is disposed at a position forming a direction angle θ13 larger than the direction angle θ11. Now, when the sound of the right channel is emitted only from the speaker SR as shown in FIG. 3A, the listener 3a perceives the direction of the sound source in the direction of reference numeral 1.

On the other hand, when the same sound is emitted from the speaker SL together with the sound from the speaker SR, the listener 3a moves almost forward in the direction of the sound source as indicated by reference numeral l2 in FIG. 3 (2). To perceive.

Therefore, the attenuators of the crosstalk generating circuits C1 to C3
By converting the level by aR by the AR and the phase by θR by the phase shifter PR, the listener 3a can perceive the right channel 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).

In this state, when the sound of the left channel is emitted from the speaker SR via the attenuator AL and the sound of the left channel is also emitted from the speaker SL via BPFF1L to F3L, the sound image is obtained as shown in FIG. Is defined as the front direction of the listener 3a indicated by the reference numeral l4, and as shown by the reference numerals l6 and l7, 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 phase θR is adjusted so as to be on the order of degrees.

Similarly, the sound image control circuits U1a to U3a
Correction amount θL in the crosstalk generation circuits C1a to C3a
By adjusting a, θRa and the attenuation rate aLa, aRa,
A symmetrical sound field can be formed. In addition, as shown in FIG. 4, the spread angle θ1 of the basic sound is set to be wider than the spread angle θ3 of the basic sound, and the spread angle 2 · θ3 of the basic sound is set to the sound effect. Phase correction amounts θLa and θR so as to be formed within the divergence angle 2 · θ1
a and the attenuation rates aLa and aRa are adjusted.

As described above, in the present embodiment, a symmetrical sound field of a symmetrical fundamental sound indicated by the reference numeral JR is formed in the driver's seat 3, whereby the sound image is localized in front of the listener 3 a without play. be able to. Further, the sound field of the sound effect indicated by the reference sign JRa is formed wider than the sound field JR of the basic sound. In this manner, the sound field JR of the basic sound and the sound field JRa of the sound effect are placed in the cabin 2 where the mounting positions of the speakers SL and SR are limited.
, The sound image can be localized in the front direction of the listener 3a, and a sound field having an expansion can be formed.

In the above-described embodiment, the optimum sound field is formed for the driver's seat 3. However, as another embodiment of the present invention, the passenger seat 4 may be set to the optimum sound field.

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, the left and right loudspeakers have the sound signals of the fundamental sounds of the left and right channels from the acoustic signal source, and the left and right speakers created based on the acoustic signal of the fundamental sound. The sound signal of the sound effect of each channel is given to the left speaker, and the sound signal of the fundamental sound and the sound effect of the right channel is given to the left speaker by adjusting at least one of the phase and the level. The same correction is applied to the sound signals of the fundamental sound and the sound effect of the left channel, so that the sound field of the fundamental sound and the sound effect of the sound effect are different at listening positions where the directional angles of the left and right speakers are different from each other. The extension of the sound field can be adjusted individually.

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 plan view showing the spread of the sound field of the fundamental sound and the sound field of the sound effect according to the present invention, and FIG. 5 is a plan view for explaining the prior art. DESCRIPTION OF SYMBOLS 1 ... In-vehicle sound reproduction apparatus, 2 ... Cab, 3 ... Driver seat, 4 ...
Passenger seat, 3a: listener, 11: sound signal source, 17: sound effect creation circuit, AL, AR; ALa, ARa: attenuator, C1 to C3; C1a to C3a: crosstalk generation circuit, PR; PLa, PRa … Phase shifter, SL, SR… Speaker, U1-U3; U1a-U3a… Sound image control circuit

Claims (1)

(57) [Scope of request for utility model registration] A right speaker and a left speaker are arranged at an interval from each other, are opposed to the right speaker and the left speaker, and are between the right speaker and the left speaker and are closer to the right speaker or the left speaker. A stereo sound reproducing device to be listened to at a listening position provided at a listening position, wherein a sound signal of a fundamental sound of a left channel is outputted to the left speaker, and a sound signal of a fundamental sound of the right channel is outputted to the right speaker. The sound signal of the fundamental sound of both the left and right channels from the acoustic signal source is given, and at least one of the phase and the level of the sound signal of the left channel is corrected and output to the right speaker, and the sound signal of the right channel is output. A basic sound adjusting unit that corrects at least one of the phase and the level and outputs the corrected sound to the left speaker; and the left and right channels from the sound signal source. The sound signal of the fundamental sound is arithmetically processed to create sound signals of sound effects of the left and right channels, and sound effect creating means for outputting the sound signals to the left and right speakers, respectively, and the sound signals of sound effects of both the left and right channels are given. And corrects at least one of the phase and level of the sound signal of the left channel and outputs the corrected signal to the right speaker, and corrects at least one of the phase and level of the sound signal of the right channel and outputs the corrected signal to the left speaker. Effect sound adjusting means, wherein at the listening position, the spread angle of the sound effect is selected to be larger than the spread angle of the basic sound, and the spread angle of the basic sound is formed within the spread angle of the sound effect. A correction value in the basic sound adjustment means and a correction value in the sound effect adjustment means, respectively.