KR930004929B1 - System of method for original sound actualization - Google Patents

Abstract

The method for generating the psudo acoustic field being similar to the original one and minimising the environmental effect of the speaker location comprises the steps: (a) generating the directional initial reflection sound which is smaller than the direct sound and is delayed for 10-70 ms after generating the direct sound; and (b) generating the undirectional reverberation which is smaller than the initial reflection sound and be delayed for a certain time after generating the reflection sound.

Description

Method and system for realization of original sound field

1a, b are negative amplitude progress diagrams for explaining the method of the present invention.

2 is a block diagram showing a system of the present invention.

3 is a system diagram of another embodiment of the present invention.

4 is a system diagram of another embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

10: main amplifier 21, 22: left and right main speaker

30: first delay circuit 31, 32: left and right directional speakers

35: first variable resistor 40: second delay circuit

41,42: left and right first omnidirectional speaker 45: second variable resistance

The present invention relates to a method and system for realizing a sound field.

Music enthusiasts who listen to music through an audio system want to hear the sound coming from the audio system as if they were playing. However, the sound produced by the audio system is quite different from the original sound field, no matter how good the performance of the audio system is, and the difference does not fully reproduce the effect that occurs in the actual performance of the music. Because you can't. In other words, the volume, reverberation, and spatial diffusion that occur in the actual performances are difficult to reproduce through the audio system.

At present, the surround system, one of the audio systems, uses a large number of spatially separated speakers to make the main speakers in the front generate the main sound, and the rear ones usually have a phase difference than the juice picker. It's supposed to occur as much as the phase difference later, so the effect is as if you were playing.

However, it is very difficult to generate a sound close to the original sound field because such a system cannot sufficiently reproduce the volume, reverberation, and spatial dispersion that occur depending on the actual place to play. That is, in order to hear good sound, the audio system is limited when conditions such as first, good volume, second, no acoustic disturbance, third, clarity, fourth, and sound have spatial diffusion are met. Only the volume can be generated, acoustic disturbances occur according to the installed place, and the frequency range is limited according to the allowable frequency range of the speaker, so that the realism as in a real performance cannot be felt.

It is therefore an object of the present invention to provide a method and system according to which sufficient original sound can be realized. Another object of the present invention is to provide a method and system according to the present invention, which generate sound similar to the original sound field and minimize the influence of the installation location of the audio system.

The objective is to first generate a direct sound, and then generate a directional early reflection of a delay after a certain period of time and a smaller magnitude than the direct sound. A system according to the present invention using such a method is connected to a first group of omni-directional speakers and a main amplifier arranged on both sides of the main amplifier via a first time delay circuit and connected to the main amplifier. It is achieved by a system consisting of a second group of directional speakers arranged on both sides of the center and a third group of speakers arranged on both sides of the main amplifier and connected to the main amplifier via a second time delay circuit.

The operation and effects of these methods and systems are described below.

First, the original sound field realization method will be described.

As explained earlier, to hear good notes

1) volume, that is, sound should be abundant

2) there should be adequate reverberation

3) There should be a sense of space diffusion

4) It is when there is clarity.

By the way, even if the same sound is heard, the sound is abundant when one sound is heard after a while and the sound is rich again. That is, the sound pressure level and the correction effect can be obtained after the direct sound. I can speak.

If the total sound pressure is called ∫ ² (t) dt and the direct sound is 94db, then the corrected sound pressure can be obtained as follows. If the sound pressure within 10ms-80ms is 90db, the sound pressure difference is 4db, so the sound pressure level is

90db + 94db = 10log (10 ^90/10 +10 ^94/10 )

= 10log (10 ⁹ +10 ^9.4 )

= 95.5db, and the corrected sound pressure is 1.5db.

In other words, this shows that the delayed sound after the direct sound can enhance the direct sound to enrich the volume.

Reverberation energy refers to the remaining energy excluding energy by direct sound among the total energy. Assuming that the time when the direct sound reaches 0-50ms, the reverberation energy is the energy of 50ms-∞ms. Is treated as a direct sound)

로 되어 서로 다른 지연시간과 진폭을 가지고 있는 스피커를 사용함으로서 유사효과를 낼 수 있음을 보여준다. 음의 공간 확산감은 초기 반사음과 공간적 파라메타인 L.E(lateral efficiency)와 R.P(room response) 그리고 IACC(interaural cross correlation)으로 요약될 수 있다. 여기서 초기 반사음에 대해서 살펴보면,Therefore, the reverberation energy is expressed as P (t) dt, so the reverberation energy

This shows that similar effects can be achieved by using speakers with different delay times and amplitudes. Negative spatial diffusion can be summarized as early reflections and spatial parameters, lateral efficiency (LE), room response (RP), and interaural cross correlation (IACC). If we look at the early reflections here,

Δt ₁ : initial delay time

d ₁ : path of the first order reflection sound

d ₀ : Distance between sound source and listener

c: sound speed

This suggests that the choice of appropriate delay time can give a sense of space spread.

Next, the spatial spatial diffusion of the sound compensates for the direct sound of the reflected sound of 10ms-80ms among the initial reflections and contributes to the subjective diffusion of sound. (Barron theory) Therefore, the optimum delay time of the reflected sound varies depending on the sound source and the autocorrelation function of the sound source Can be obtained as That is, the delay time of the optimum initial reflection sound coincides with the delay time at which the range of the autocorrelation function of the sound source is 0.1 times the reflection sound level A1.

That is, [Δt ₁ ] P = τd

│P _p (τ) │ = 0.1al

Becomes

Next, in order to enrich the volume, it is necessary to consider the overall sound by identifying the phase relationship between the direct sound and the sound that is reflected or diffracted. In the system according to the present invention, the sound sense is responsible for the direct sound in consideration of the phase relationship, so that the sound is generated in the directional speaker of the second group by delaying the sound of the first group without the omnidirectional speaker sound. Therefore, the sound is generated from the speaker of the second group slightly behind the speaker of the first group that emits the direct sound, so that the user can feel a psychologically strengthened volume.

However, if the delay time is set too long, echo sound will occur and the intelligibility will be reduced, so it is recommended to set the delay time as 30ms-60ms, but the second group amplifier design may be set to 10ms-100ms, and the third group amplifier delay time is Another good design method is to set the 80ms-160ms and the fourth group amplifier delay time by 150ms-300ms.

The spatial diffusion is achieved by delayed reflections of 10ms-80ms among the initial reflections, which reinforces the direct sound and makes the sound feel subjective. At this time, a sense of diffusion of sound is felt when the sound is heard at an angle of about 30 ° to about 70 ° at both ears of the listener.

In particular, since the diffused feeling exhibits an optimum value near about 55 °, the present invention generates a delayed sound between about 10 ms and 80 ms without any difficulty in intelligibility, so that the directional speaker can be heard in the direction of about 55 ° to the listener's ear. Installed.

Therefore, by adjusting the delay time and the amplitude, the initial reflection sound is artificially adjusted to give a sense of spatial diffusion.

This is expressed as follows. If the actual sound is generated at a time t = 0 as shown in FIG. 1a, the sound is extinguished with time. However, to reproduce all of these sounds in an audio system is practically impossible because of the limitations of speaker performance and the need for a large number of speakers. Therefore, as shown in Fig. 1b, the sound that has an important effect on hearing among the sound that disappears over time is classified into direct sound, early reflection sound, and first reverberation sound to delay the time and adjust the amplitude of the sound. In this case, the envelope of the sound reproduced by the speakers is the same as the envelope of the sound actually disappearing, so that the original sound can be reproduced. That is, the sound generated at time t = 0 is called the direct sound, and the sound generated at time t = 30ms-70ms is the initial reflection sound, and the sound generated at time t = 100ms is used for the first reverberation sound and time t = 150ms. Naturally, the generated sound can be further divided according to the number of installations by dividing the sound into the second direction sound. (The criteria for classifying the delay time can be changed and adjusted according to actual convenience since the numerical values shown above are optimal values.)

This invention will be described in more detail in accordance with FIG.

The right main speaker 21 is connected to the right side of the main amplifier 10 and the main amplifier 10, and the left main speaker 22 is connected to the main amplifier 10, respectively. However, the left and right main speakers 21 and 22 have the same characteristics and generate a direct sound corresponding to about 50-70% of the total energy.

However, 50% -70% energy ratio is one of the ways to increase the intelligibility.

Next, the right-directional speaker 31 is connected to the first delay circuit 30 on the right side of the main amplifier 10 and the left-side speaker 32 is connected to the first delay circuit 30 on the right side of the main amplifier 10. It is connected to the main amplifier 10 through a variable resistor (35). However, the left and right directional speakers 32 and 31 have the same characteristics, and generate a directional sound after the delay time of the first delay circuit 30. The adjustment of the first variable resistor 35 results in 10 Generates early reflections of -30%.

Next, the right first non-directional speaker 41 is connected to the second delay circuit 40 on the right side of the main amplifier 10, and the left first non-directional speaker 42 is on the right side of the main amplifier 10. ) Is connected to the main amplifier 10 through the second variable resistor (45).

However, the left and right first omni-directional speakers 42 and 41 have the same characteristics, and generate omni-directionalness later by the delay time of the second delay circuit 40. It produces about 10-20% of reverberation.

Here, the delay time of the first delay circuit 30 is set to about 10ms-70ms, which is a time at which no sound is generated, and the delay time of the second delay circuit 40 is also set to about 70ms-100ms.

Referring to the operation of the system according to the present invention configured as described above, the sound is not generated by the delay time set by the first delay circuit 30 after the sound is generated in the left, right main speaker (22, 21). The delayed sound of 10 ms to 80 ms is generated in the left and right directional speakers 32 and 31 to be smaller than the sound generated in the left and right main speakers 22 and 21. After a while, that is, the sound delayed from 70ms to 100ms, which is the delay time set by the delay circuit of the second delay circuit 40, is smaller than the sound generated from the left and right omnidirectional speakers 32 and 31. Occurs at 41).

However, the sound generated by the parallax is a sound of the same frequency, only the amplitude is different from each other, so that it becomes a correction sound to give the listener a psychologically rich volume. And the sound generated from the left and right directional speakers (32, 31) is a side reflection sound to the listener due to the directivity of the speaker gives a feeling that the sound is spread.

The sound generated from the left and right first omni-directional speakers 42 and 41 is the smaller than the sound generated from the main speakers 21 and 22 or the directional speakers 31 and 32 and is generated later. Therefore, the other sound is different from the main speakers 21 and 22. Even when this occurs, the background sound is spread to make the listener feel reverberation. Therefore, when the sound continues and the main speakers 21 and 22 continue to generate sound, they are connected to other speakers in turn, thereby achieving harmony as a whole. Nevertheless, the output of the main speakers (21, 22) responsible for the direct sound occupies 50-70% of the total energy, so the clarity can also feel the sense of reality does not fall.

FIG. 3 is another embodiment according to the present invention and is the same as FIG. 2 except that each speaker is connected to the main amplifier through each delay circuit and a variable resistor.

3 shows a stereo sound system, since the sound for the left speaker and the sound for the right speaker are different so that one common signal line and a delay circuit variable resistor cannot be used to connect the left and right speakers. That is, in FIG. 3, the directional speaker 31 on the right side is connected to the main amplifier 10 through the first delay circuit 301 and the first variable resistor 351, and the directional speaker 32 on the left side is connected to the first amplifier. The delay circuit 302 and the first variable resistor 352 are connected to the main amplifier 10. In addition, the first non-directional speaker 41 on the right side is connected to the main amplifier 10 through the second delay circuit 401 and the second variable resistor 451, and the first non-directional speaker 42 on the left side is formed of a first non-directional speaker 42. The second delay circuit 402 and the second variable resistor 452 are connected to the main amplifier 10.

Accordingly, if the delay circuit and the variable resistor for the corresponding left and right speakers are adjusted, stereo music can be enjoyed on the same principle as in FIG. In addition, in FIG. 3, even when listening to music other than stereo, a stereo-like effect can be enjoyed by slightly changing the delay circuit and the delay time for the corresponding speaker.

4 is a configuration in which the left and right second omnidirectional speakers are provided in the same configuration as that in FIG.

Referring to FIG. 4, it can be seen that it is the same as FIG. 2 except for the left and right second omnidirectional speakers 52 and 51, the third delay circuit 50, and the third variable resistor 55. That is, the right second non-directional speaker 51 is connected to the third delay circuit 50 on the right side of the main amplifier 10, and the left second non-directional speaker 52 is on the right side of the main amplifier 10. The third variable resistor 55 is connected to the main amplifier 10. In this case, the left and right second omnidirectional speeches 52 and 51 have the same characteristics, and generate omnidirectionality by the delay time of the third delay circuit 50. The output is adjusted according to the output of other speakers. Here, the delay time of the left and right second omnidirectional speakers 52 and 51 is adjusted to generate a delayed sound than the first omnidirectional speakers 42 and 41, and the left and right second omnidirectional speakers are first omnidirectional. As the speaker produces sound smaller than the speaker, the main speakers 22 and 21 generate sound, and then the sound is generated in the order of directional speakers → left and right first omnidirectional speakers → left and right second omnidirectional speakers. You can get an effect that makes you feel more reverberation.

Claims (5)

A method of directly generating sound by retarding a sound generated by a main speaker and a booth speaker, the method comprising: generating a directional initial reflection sound having a predetermined delay after the direct sound is generated and having a size smaller than that of the direct sound; A method of realizing an original sound field comprising the steps of generating an omnidirectional reverberation that is delayed and smaller than the initial reflection. The method of claim 1, wherein the delay time between the direct sound generation and the directional initial reflection sound is 10ms-70ms. A first group of non-directional main speakers arranged in both sides of the main amplifier and the main amplifier and the main amplifier and the main amplifier and the second group of directional speakers and the main amplifier, respectively, connected to the main amplifier through a first time delay circuit. An original sound field realization system comprising a third group of omni-directional speakers arranged on both sides of the main amplifier through a second time delay circuit. 4. The original sound field realization system according to claim 3, wherein the delay time of said first time delay circuit is shorter than the delay time of said second time delay circuit. 5. The system according to claim 3 or 4, wherein the output of the omni-directional main speakers of the first group is 50-70% of the total energy (total sound output of the speakers of the first to third groups).

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