JPS63202200A - Audio equipment - Google Patents

Abstract

PURPOSE:To create sound field of a stage not provided to a conventional delay device with a less reproducing system by retarding the time of left/right stereo in-phase signals, inverting the phase of a delay signal and adding it to a stereo signal so as to abolish a rear speaker. CONSTITUTION:Stereo signals 12, 13 are sent to power amplifiers 1, 2 via inverse amplifiers 14, 15 to drive front speakers 3, 4. On the other hand, the signals 12, 13 are added by resistors 17, 18, applied to a delay device 9, inverted by an inverse amplifier 16, then applied to a main signal system by variable resistors 19, 20 and sent to the amplifiers 1, 2. A delay device 9 is in use to delay a low frequency in-phase signal of the sound source to increase the phase difference and the level reduction is suppressed at a low sound frequency when the result is added inversely with a main signal. Moreover, the delay signal is a sound having the echo of a 1st order reflection sound so as to be listened to near the stage of a hall because the signal creastes the 1st order reflection sound, and the low frequency sound increases the source energy per unit time by the spectrum due to the reflected sound to enhance the rich low frequency tone with echo.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an audio device that performs delay control on audio signals.

2. Description of the Related Art In recent years, in audio, sound field control using time delay, typified by DSP (digital signal processor), has been attracting attention.

An example of a conventional audio device will be described below with reference to the drawings.

In FIG. 6, power amplifiers 1 and 2 drive front speakers 3 and 4, rear speaker cuffs 5 and 6, power amplifiers that drive each of 8, and speakers 3, 4, 7, and 8 are located in the squares of the listening room 11. 8 is installed.

The operation of the audio device configured as described above will be explained below.

Stereo left and right signals 12.13 are buffer amplifier 1o
Since the structure is configured such that the signal is reproduced from the front speakers 3 and 4 via the front speakers 3 and 4 and is also applied to the time delay device 9 and reproduced from the rear speaker cuff 8, even in a small listening room 11, a signal with a time delay is transmitted from the rear speaker cuff 8. Because it is played back, it feels like the sound is reflected from the walls of a large hall.

Problems to be Solved by the Invention However, in the above configuration, the power amplifier is
The cost is higher than normal stereo because it requires a stand, and since the sound always comes from behind the listener, the sound from the front speakers may not be clear, and the sound may not be clear when listening from the center of the hall. Although it can be used for sound, if you want to hear high-fidelity sound at the front near the stage of the hall, you need to lower the volume of Rear Bee Cuff and 8.
In the end, there were problems such as the reason for the existence of the rear b-cuff and 8 to diminish.

In view of the above-mentioned problems, the present invention makes the sound localized in the center from the front speakers clear, maintains the sense of separation between left and right stereo, and adds resonance to the sound localized in the center such as vocals, and improves the clarity of the sound localized in the center of a large hall. The present invention provides an audio device that reproduces a nearby sound field.

Means for Solving the Problems In order to solve the above problems, the audio device of the present invention time-delays stereo left and right in-phase signals, inverts the phase of the delayed signals, and converts the stereo signals into electric or acoustic signals. , and does not require a conventional rear beaker.

Operation The present invention does not require four power amplifiers and can create a stage sound field that is not available in conventional delay devices by using a maximum of three power amplifiers or a two-channel regeneration system like a normal stereo.

Example An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an audio device according to a first embodiment of the present invention. In FIG. 1, numerals 14 and 15 are inverting adders, but non-inverting adders have the same effect. 1e is an inverting amplifier of the present invention.

The operation of the above configuration will be explained.

A stereo signal 12.13 is applied, and the main signal is transmitted to the power amplifier 1.2 via an inverting adder 14.15 to drive the front speakers 3 and 4.

On the other hand, the stereo signals 12 and 13 are added by resistors 17 and 18, applied to the delay device 9, and inverted by the inverting amplifier 16, and then applied to the main signal system by the volumes 19 and 20. It will be played from 4. ' With the above configuration, the in-phase signal of stereo H is inverted and applied to the main signal, so if the delay time of the delay device 9 is zero, it works as a subtraction of the main signal, so the speaker 3, The sound played from 4 onwards becomes quieter. However, in general, music sources have many signals other than the same phase, and especially in high-pitched sounds, there are many signals with completely different phases on the left and right sides, so if the volume is 19.
, 20, the level of the main stereo signals (especially high-pitched sounds) reproduced from the speakers 3 and 4 is not subtracted at all. On the other hand, the inverted in-phase signal is sent to the left and right speakers 3.
, 4 to the volumes 19 and 20 are added to the main signal and reproduced, so the signal localized in the center (
(in-phase signal) increases and becomes clearer. On the other hand, in this state, the low-frequency signal with a long wavelength has a phase difference compared to the high-pitched sound, so it is reduced by the in-phase amount after being added by the volumes 19 and 20, resulting in a signal with a lower bass volume. Therefore, in the present invention, by delaying the low frequency in-phase signal using the delay device shown in FIG. 1, it is possible to prevent the bass level from decreasing when it is inverted and added to the υ main signal with a large phase difference. . In addition, the delayed signal creates the first reflected sound of the hall, so the first reflected sound is similar to that heard near the stage of the hall, resulting in a glittering, glossy, and resonant sound, and the bass is also reduced. The source energy per unit time is increased by the reflected sound spectrum, resulting in a rich and resonant bass sound.

A detailed explanation will be given below using specific numerical values.

FIG. 3 shows the state when listening to normal stereo left and right speakers, and the sounds reaching both ears from the speakers 4 are synthesized by the human auditory sense, with a time difference τ equal to the width of the face of the person 24. As shown in Figure 4, a dip occurs in the middle tones with an opposite phase spectrum.Similarly, the left speaker 3
The sound emitted from the speaker also causes a dip in the midrange, so the midrange cannot be heard clearly.

If the speaker 22 is placed in the center, there will be no phase difference between the two ears because τ,=τ2, and no dip will occur in the middle castle as shown in FIG. Therefore, the in-phase signal L is sent to the left and right speakers at 3°4.
-) Even if there is a signal that is localized to the center by applying -R, the sound cannot be clearly heard due to the dip in characteristic a. Therefore, in order to clarify the signal located in the center,
It needs to be strengthened somehow. That is, in the present invention, left and right stereo signals are added to produce an in-phase signal, which is made to have an opposite phase and is further applied to the main signal via a delay means.

For example, the delay time is 0.5! II When the BeJO signal is applied in opposite phase, the stereo in-phase signal is canceled at low frequencies below the ratio of 2, but the time difference between both ears is 0.5 m86.
Below 0 (more than 2), the phase is rotated by the time difference between both ears, and the opposite phase becomes in-phase and emphasized, and 2K
) Signals of 12 or more will be audible with emphasis as much as they are added.

If the delay time is further increased, the canceled frequencies move to a lower frequency band, resulting in richer bass. This is because the phase of the anti-phase signal changes by the delay time. By changing the delay time in this way, the level of the low-frequency signal changes, while the high frequencies are not canceled as a delayed signal but are heard as a reflected sound as a new spectrum and are therefore emphasized, resulting in a clearer sound. Furthermore, if the delay time is increased until almost no bass is canceled, a resonant spread from bass to treble will be created. In other words, mid-range sounds such as vocals are emphasized and clear in the same phase, and high-range sounds such as cymbals are reproduced as reflected sounds with a time difference and sound with resonance and spaciousness.

Also, by inserting an equalizer between the delay device 9 and the inverter 160 to increase the level of the midrange, the midrange becomes clearer.
When an equalizer is added to the main signal, the sound is clearer and has more resonance and spaciousness due to the delay. Furthermore, if the delayed signal is applied to the main signal with the same phase, a dip will occur in the midrange and the sound will not be clear.

In addition, the method of changing the phase of the delayed signal and applying a signal with a different phase to either the left or right side gives the left and right stereo speakers a wide spread, but the clarity, size, and clarity of the sound image localized at the center as shown in the present invention can be improved.・It is not possible to control the spread.

Furthermore, since the embodiment shown in FIG. 1 does not have the amplifier 6.degree. 6 speaker 7.8 shown in FIG. 6, it is advantageous in terms of cost and space.

Further, an even better effect can be produced by inserting an equalizer that corrects the frequency characteristics of the delayed signal between the delay device 9 and the inverter 160 to slightly correct the vocal band. For example, it is possible to make the vocal sound localized in the center clearer, and it is possible to create an effect that is completely different from simply providing an equalizer in the vocal band using the main signal. Furthermore, by controlling the delay time and the volume and phase of the signals to be inverted and added, it is possible to create new effects.

Further, the delay device 9 may be a digital delay such as a RAM or a shift register, or an analog delay such as a BBD.

Furthermore, although conventional delay devices required two or more channels, the present invention can provide sufficient effects with just one channel.

In addition, means such as delay, equalizer, inversion, and addition are performed by DSP.
A similar effect can be obtained by using a digital arithmetic unit such as a digital signal processor (digital signal processor).

The second embodiment of the present invention will be described below with reference to the drawings. In FIG. 2, 21 is a power amplifier, 22 is a center speaker, and 23 is a volume. The difference from the first embodiment is that the signal obtained by adding and delaying the stereo left and right signals is not added to the main signal, but is sent to the center speaker 22 via the third amplifier 21.
This is the point from which a center localization signal is output. That is, in the first embodiment, the main signal and the delayed signal are electrically added together, whereas in the second embodiment, the polarity of the voice coil of the center speaker 22 is reversed to add the main signal and the delayed signal acoustically to the left and right speakers 3°4. Since they are added together, there is less cross-modulation and crosstalk between the left and right signals and the center delay signal, and the sound that is localized to the center is clearer, producing a faithful sound that is much closer to the stage than the first embodiment. Furthermore, it is also possible to change the position of the speaker 22 arbitrarily and enjoy the music.

Also, as explained in the first embodiment with FIGS. 3 and 4, placing the third speaker 22 in the center of the left and right speakers,
The fact that it has excellent transmission characteristics that do not cause dips in frequency characteristics is a totally unprecedented effect.

Effects of the Invention As described above, the present invention provides a delay device, an inverting means, and an electrical or acoustic addition means for adding the main signal. As a result of experiments, the effect was found to be remarkable. In addition, when the frequency characteristics are changed by changing the delay time of the phase-inverted delay signal, by varying the amount of the delay signal or varying the delay time,
The size of the sound image of the sound localized in the center can be expanded and the sound quality can be changed, creating a completely new effect that has never been seen before.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an audio device according to a first embodiment of the present invention, FIG. 2 is a configuration diagram of a second embodiment of the same, FIG. 3 is a plan view for explaining sound transmission characteristics, and FIG. FIG. 4 is a frequency characteristic diagram, and FIG. 6 is a configuration diagram of a conventional audio delay device. 1.2,5.6...Power amplifier, 3,4,7
゜8.22... Speaker, 9... Delay device, 10... Buffer amplifier, 11...
・Listening room, 12.13... Stereo signal input,
14.15...Inverting amplifier, 16...
Inverting amplifier, 17.18...Additional resistor, 19.
20.23...Additional volume, 24...
...listener. Name of agent: Patent attorney Toshio Nakao and one other person
2-No v7-Asode 3・4--Sujiichi force A4~fθ---Reverse Asode 2nd figure 3 Figure 2 Cow figure 4 River 5X Soft figure 5

Claims (2)

[Claims] (1) An audio device characterized in that stereo left and right signals are added, the signal is delayed and phase inverted, and the delayed phase inverted signal is added to the stereo left and right signals. (2) After adding and delaying the stereo left and right signals, the signal is applied to a third speaker provided in addition to the first and second speakers that reproduce the left and right signals, and An audio device characterized in that the phases of a signal to be applied and a signal to be applied to a third speaker are inverted.