JPS62295600A - Acoustic reproducing device - Google Patents

Abstract

PURPOSE:To reproduce a sound field closer to an original sound field by providing left/right speakers placed at both sides of a listening position and an upper speaker placed nearly above the said listening position or at the back above and reproducing a sound signal at least retarding the sound signal fed to the said left/right speakers. CONSTITUTION:An echo circuit 4 consists of mixers 41, 42, a delay circuit 43, and gain adjusting circuits 44, 45 bringing its output level to an input level or below, an output signal from the circuit 3 and a signal from the circuit 45 are mixed (added) by the mixer 42 and its output is retarded by a delay circuit 43. The output is subjected to level adjustment by the circuit 44 and its output is mixed (added) with the output signal of the delay circuit 3 by the mixer 41. Variable resistors (VRs) are intelocked together, and the VR1 is used for a side L speaker 10, the VR2 is used for a side R speaker 11, the VR 3 is used for a surrounding center speaker 12, the VR 4 is used for a surround L speaker 13 and the VR 5 is used for surrounding R speaker 14.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention makes it possible to obtain a natural listening window that is almost the same as the original sound heard in a wide space such as a concert hall. Regarding playback equipment that reproduces sound with a rich sense of presence,
In particular, the present invention relates to a sound reproduction device that reproduces sound in a personal zone near the ear without bothering others.

[Prior art]

Comparing the listening window and the physical quantities related to it, we find that ■, Sense of presence/spreading - lateral component ■, Richness of sound/loudness - initial reflection energy ■, Sense of forward localization/balance - front-to-back ratio ■ , clarity - intelligibility, sound reverberation - reverberation time, brilliance of sound - treble/middle range, and bass perception - bass/middle range. It is effective in evaluating acoustic listening windows, and covers all of the transient characteristics, steady-state characteristics, and directivity of the sound field under the condition that the listening location is constant.

In recent years, a wide variety of methods have been considered, called surround, in an attempt to create an aurally rich sense of presence.

The main method is to create a feeling of being surrounded by sound. This method places speakers not only in front of the listener but also behind them.

Specifically, the acoustic signal to be supplied to one or more rear speakers may be, for example, a signal obtained by delaying the left and right sounds from the front, or a signal of the difference between the left and right sounds, taking into account the above-mentioned physical quantities. etc., and further reproduced as a signal combining the above-mentioned physical quantities.

However, in conventional surround playback, the various physical quantities described above are adjusted so that the sound played from the front left and right speakers collides with the sound played from the rear surround speakers in almost opposite directions. The aim is to provide a good listening experience, that is, to give the feeling of being surrounded by sound.

Therefore, the sound field heard by the listener is a sound field (two-dimensional sound field) formed by the sound from the front and the sound from the rear.
Therefore, compared to the original sound field in a large space such as a concert hall, there was a need for further improvement.

[Purpose of the invention]

An object of the present invention is to provide a sound reproduction device that can surround a listener with a three-dimensionally considered sound field and reproduce a sound field closer to the original sound field.

[Structure of the invention]

For this purpose, the sound reproduction device of the present invention includes left and right speakers installed on both sides of a listening position, and an audio signal that is installed approximately above or above and behind the listening position and that is at least delayed from the audio signal supplied to the left and right speakers. The device is equipped with an upper speaker for reproducing signals.

〔Example〕

Examples of the present invention will be described below. FIG. 1 is a diagram showing the sound reproduction circuit. 1.1' is an input terminal into which the R channel audio signal and L channel audio signal are input;
2.2' is a buffer, 3.3' is a control terminal 3a, 3a
This is a delay circuit whose delay time can be adjusted by a control pulse applied to l.

Further, 4.4' is an echo circuit, and one echo circuit 4 consists of mixers 41 and 42, a delay circuit 43, and gain adjustment circuits 44 and 45 that keep the output level below the input level. The output signal and the signal from the gain adjustment circuit 45 are mixed (added) by the mixer 42, the output is delayed by the delay circuit 43, the level of the output is adjusted by the gain adjustment circuit 44, and the output is added by the mixer 41 to the delay circuit 3. A part of the output of the gain adjustment circuit 44 is input to the gain adjustment circuit 45 and repeatedly mixed with the first signal by the mixer 42.

Therefore, the gain of the gain adjustment circuit 44.45 is set to the terminal 44.
A desired reverberation can be added by adjusting the delay time of the delay circuit 43 with a pulse applied to the terminal 43a. This reverberation time interval is, for example, 100m5.
~ several ms is preferable. Since the other echo circuit 4' has a similar configuration, similar components are denoted by the same reference numerals fL.
” was added. Note that the terminal 43a of the delay circuit 43, 43'
If the control pulse to 143a' is stopped, the sound will be delayed by the delay circuit 3.3' without reverberation.

5 is a sound quality adjustment circuit that inputs the output signal from the echo circuit 4.4' and adjusts the frequency characteristics; for example, 10KH.
Adjusted to cut components of z or higher. Note that the sound quality may be adjusted by a control signal to the terminal 5a by changing the cut component or making the sound uncut, depending on the sound preference. Reference numeral 6 denotes an addition/subtraction circuit that subtracts and adds the two input signals output from the sound quality adjustment circuit 5 at an appropriate ratio, or outputs them as an R signal, and is switched by a control signal from the terminal 6a.

7 subtracts the output signal from the echo circuit 4.4' (L
-R) Subtraction circuit; 8 is a low-pass filter that extracts components below 7 KHz from the output signal from the subtraction circuit 7; 9;
is a noise removal circuit.

VRI to VR5 are linked variable resistors for volume adjustment, VRI is for side I speaker 10, VH2 is for side R speaker 11, VH2 is for surround center speaker 12, VH2 is for surround L speaker 13.
VH5 is for the surround R speaker 14 (see Fig. 2).

Note that the delay circuits 3.3' and 43.43' described above can be configured with a BBD (packet brigade device), but a C0D (charge coupled device) can also be used. It is possible. However, when using this CCD, for example, buffer 2
．． The input signal after 2' is modulated at high frequency and sent to the CCD.
It is necessary to delay the signal and then demodulate it into a low frequency component using a circuit before circuit 4.5.7, for example.

FIG. 2 is a diagram showing an example in which the sound reproduction device of this embodiment is incorporated into a chair 20. In this chair 20, a device 21 comprising the circuit component described above is attached to the right arm rest 22, and speaker holders 24 to 26 made of pipes are mounted on both sides of the head rest 23 at the upper part of the backrest. is the mounting bracket 27.2
It is attached by 8.

The speaker holder 24 extending upward from the mounts 27 and 28 has a surround center speaker 12, an L speaker 13, and an R speaker 14 mounted on the upper part thereof so that their sound emission direction is downward. A cabinet 29 loaded therein is rotatably attached in the direction of arrow A. Further, the speaker holder 24 is also movable in the direction of arrow B, that is, in the vertical direction.

More specifically, the cabinet 29 is located in a zone approximately above and behind the ears of the listener sitting on the chair 20, and the sound emitted from the speakers 12 to 14 is emitted from above the listener's head. Alternatively, it is installed facing the listener from the top and rear.

Further, side speakers 10 and 11 are attached to other speaker holders 25 and 26 so as to be rotatable in the directions of arrows c and c'. In addition, this speaker holder 25.26
is also movable in the direction of arrow B.

Now, the R and L channel audio signals applied to the input terminals 1.1' are input as they are to the variable resistors VRI and VH2, and are reproduced by the side speakers 0 and 11, thereby performing conventional stereo reproduction.

The audio signal input to the delay circuit 3.3' is delayed there before being input to the echo circuit 4.4'. At this time, the delay times of the delay circuits 3 and 3' can be made different.

In the echo circuit 4, the first arriving sound signal passes through the mixer 42, the delay circuit 43 (gain adjustment circuit 44), and is mixed with the sound signal after the delay time set by the delay circuit 43 has elapsed at the mixer 41. The first echo of the sound signal is an echo that has been attenuated only in the gain adjustment circuit 44 compared to the original.The second echo enters another gain adjustment circuit 45 and then is sent to the mixer 42 and delay circuit 43. , reaches the mixer 41 via the gain adjustment circuit 44, so 1
Compared to the initial signal, it is further delayed in time and is greatly attenuated. The third and fourth shots will have a greater delay and attenuation. Since this action is performed in a complicated manner, it becomes possible to add a desired echo. and,
Delay time setting of delay circuit 43, gain adjustment circuit 44.4
By appropriately setting the gain of 5, it becomes possible to realize a reverberant sound that matches the actual hall. The above also applies to the other echo circuit 4'.

Note that the echo circuit 4.4' may be a circuit that delays only once. In this case, either omit circuits 42 and 45, or
Alternatively, the output of the circuit 45 may be made approximately zero by a control signal to the control terminal 45a.

In addition, if an echo is not required, the control terminal 4 of the circuit 44
4. The gain of the circuit 44 may be set to zero by the control signal to a. It is necessary to perform these operations similarly for the other echo circuit 4'.

The circuit from the subtraction circuit 7 to the noise removal circuit 9 is L
-R signal is being processed. Here, echo circuit 4.
This cancels out the in-phase components of the L channel component and R channel component of the output signal from 4', and in an actual hall, the high frequency component of the echoes from the walls etc. is greatly attenuated.
Correspondingly, high-frequency components are cut by a low-pass filter 8, and components from which noise components are removed by a noise removal circuit 9 are reproduced from a surround center speaker 12. Therefore, a complex reverberant sound is reproduced from the center speaker 12, which is a pseudo-reverberant sound obtained by mixing a plurality of sounds reflected from the back and upper walls of a hall or the like in a multipath manner.

The sound quality adjustment circuit 5 attenuates the high frequency components of the output signal from the echo circuits 4 and 4', for example by canting the components above 10 KHz or the components above other frequencies, or sends them to the adder/subtractor circuit 6 without cutting them at all. Send. The two outputs of the adder/subtractor circuit 6 provide signals such as αL-βR1αR-βL, which are obtained by subtracting appropriate amounts of the signal components of both channels.

α and β are coefficients, and α≦1 and β≦1. Therefore,
When α-1, β=0, the L and R signal components are obtained separately, and when α-〇, β=1, the signal component with the channel inverted, such as -R, is obtained. Obtained by separation.

By the above-mentioned surround side speakers 12 to 14, the L channel sound from the side and the L channel sound are reflected in the hall and converted into indirect sound that has undergone various transformations in phase, time, level, path, and frequency. Played as a simulated voice.

Since the surround speakers 12 to 14 are installed above and behind the headrest 23, the direction of sound emitted from the side speakers 10 and 11,
The traveling directions of sounds emitted from the surround speakers 12 to 14 intersect at or near the head rest 23 so as to be substantially orthogonal to each other. Therefore, for a listener who is sitting on the chair 20 and resting his or her head on the headrest 23, a three-dimensional sound field is formed at the head of the listener, and this sound field is similar to the original sound field that occurs in a concert hall or the like. This results in a playback sound field that sounds as natural as in the previous version, and the surround effect is extremely good.

FIG. 3 shows another embodiment, in which the above-mentioned speakers 10 to 14 are assembled in the above-mentioned positional relationship into a speaker holder 30 having a U-shaped cross section and closed on both sides in the longitudinal direction (lateral direction). It is designed to be removably fitted into the upper part of the backrest part 41 of the chair 40, and the above-mentioned second part
The operation and effect are exactly the same as in the case shown in the figure.

The shape of the speaker holder 30 may be simply a horse saddle shape; in this case, the left and right speakers 10 and 11 are attached to the sheath part, and from there the left and right speakers 10 and 11 are attached to the metal fittings extending upward. It is only necessary to attach surround speakers 12 to 14.

Further, this metal fitting may be formed into a closed rectangular shape, and the surround speakers 12 to 14 may be attached to the upper part of the fitting, and the speakers 10 and 11 of the left and right pieces may be respectively attached.

Further, in addition to the above, even if the speakers are incorporated in a stand (not shown) in the same positional relationship as above, the same effects as above can be obtained.

〔Effect of the invention〕

As described above, the present invention is characterized in that a natural-sounding sound field that is extremely close to the original sound field in a concert hall or the like can be generated in a personal zone near the ear without bothering others.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a sound reproducing circuit according to an embodiment of the present invention, and FIG. 2 is a perspective view of a chair showing an example of speaker arrangement according to the present embodiment.
FIG. 3 is a perspective view of a speaker holder according to another embodiment. 1.1'...input terminal, 2.2'...buffer, 3
．． 3'...delay circuit, 4.4' circuit, 5...
Sound quality adjustment circuit, 6... Addition/subtraction circuit, 7... Subtraction circuit, 8... Low pass filter, 9... Noise removal circuit, 10.11... Side speaker, 12-14...
Surround speaker, 20...chair, 30...speaker holder, 40...chair. Agent Patent Attorney Tsuneaki Nagao Diagram 0

Claims (4)

[Claims] (1) Left and right speakers installed on both sides of the listening position,
A sound reproduction device comprising: an upper speaker which is installed substantially above or above and behind the listening position and which reproduces an audio signal that is at least delayed from the audio signal supplied to the left and right speakers. (2) The sound reproduction device according to claim 1, wherein the left and right speakers and the upper speaker are attached to a backrest of a chair. (3) The sound reproduction device according to claim 1, wherein the left and right speakers and the upper speaker are attached to a stand. (4) The upper speaker is attached above or above and behind a speaker holder that supports the left and right speakers, and the holder is placed over the upper part of the backrest of the chair. The sound reproduction device according to item 1.