JPH0819086A - Acoustic reproduction system - Google Patents

Abstract

PURPOSE:To obtain the effect that a timing of a sound reproduced from a speaker and a timing of a sound reached directly from the speaker are in matching with each other at all times at a listening position by correcting a delay of the sound based on a temperature in the vicinity of the listening position. CONSTITUTION:A temperature sensor 25 is provided in the vicinity of a listening position being a reference of a hall and sensed data by the temperature sensor 25 are fed to a central controller 21 via an A/D converter 26. When sound is reproduced actually as a concert in the acoustic reproduction system, the temperature data at the listening position detected by the temperature sensor 25 are discriminated by the central controller 21 for each prescribed period (e.g. each minute) as to a difference between a current temperature and a temperature at the initial setting stored in a memory. Then the delay in digital voice data processing circuits 13a-13n is corrected in real time based on the discriminated temperature difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound reproducing system suitable for reproducing sound signals in a relatively wide space such as a concert hall.

[0002]

2. Description of the Related Art Conventionally, when an audio signal such as music is reproduced by a speaker in a relatively wide space such as a concert hall, a process of slightly delaying the reproduction timing is performed according to the installation position of the speaker. There is. That is,
For example, when the sound picked up on the stage is amplified and played back from the speaker placed in the audience seat, it is played back from the speaker so that the timing of the sound directly reaching the audience seat from the stage matches the timing of the sound played from the speaker. Delay the sound slightly. This delay processing is performed because the speed of sound transmission in space is relatively slow.

FIG. 3 is a diagram showing an example of a conventional sound reproduction system in which this kind of processing is performed. In the figure, reference numeral 1 denotes an input terminal for an audio signal, and a microphone on the stage picks up the input terminal 1 Provides an acoustic signal. And this input terminal 1
The audio signal obtained in step 1 is supplied to the analog / digital converter 2 to be digital audio data, and this digital audio data is supplied to the digital audio data processing circuit 3. The digital audio data processing circuit 3 is a circuit called a digital signal processor (DSP), and is a circuit for performing various processing such as delay processing and processing as an equalizer. The processing in the digital audio data processing circuit 3 is performed under the control of a central control unit (CPU) 7 composed of a microcomputer.

Then, the digital audio data processing circuit 3 delays the audio data by a time set based on the operation of the operation unit 8 connected to the central control unit 7. Then, the audio data subjected to the processing such as the delay is supplied to the digital / analog converter 4 to be converted into an analog acoustic signal, and this acoustic signal is amplified by the output amplifier 5. Then, the amplified acoustic signal is supplied to the speaker 6 to emit a sound.

Here, when setting the delay amount in the digital audio data processing circuit 3, for example, a reference sound source is installed on the stage, and the sound output from this sound source is installed in the audience. The time difference from the sound being output from the sound source to the sound being picked up by the microphone is measured. Then, this time difference is taken as the time until the sound reaches the audience, and the amount of delay in the digital audio data processing circuit 3 is taken as the measured time difference.

By doing so, there is no time difference between the sound reproduced from the speaker and the sound arriving directly from the sound source (stage) at the listening position such as seats, and good sound reproduction is performed.

[0007]

However, even if the sound reproduced from the speaker is adjusted in advance so that there is no time difference, the sound reproduced from the speaker and the direct stage sound can be heard when performing a concert or the like. There was a case where there was a time lag between the sound coming from and.

SUMMARY OF THE INVENTION In view of the above points, an object of the present invention is to make it possible to control an audio reproduction system of this type so that the timing of a sound reproduced from a speaker and the timing of a sound directly reaching the speaker are always in proper states with no time difference. To do.

[0009]

According to the present invention, for example, as shown in FIG. 1, input audio signals are delayed by digital audio data processing circuits 13a, 13b. The sound reproduction system for outputting includes a temperature detecting means 25 for detecting the temperature in the vicinity of the listening position and a delay amount controlling means 21 for correcting the delay amount according to the temperature detected by the temperature detecting means 25. .

Further, in this case, the delay amount is corrected based on the temperature difference between the temperature when the initial value of the delay amount is set and the current temperature detected by the temperature detecting means 25. .

Further, in each case, a plurality of speakers are provided, and the delay amount individually set for each speaker is individually corrected according to the temperature detected by the temperature detecting means 25. .

[0012]

According to the present invention, the delay amount is corrected by the temperature in the vicinity of the listening position. Therefore, even if the temperature in the vicinity of the listening position changes, an appropriate delay amount is set and the sound reproduced from the speaker is reproduced. The timing with the sound that arrives directly will always match at the listening position.

In this case, the delay amount is corrected on the basis of the temperature difference between the temperature when the initial value of the delay amount is set and the current temperature detected by the temperature detecting means, so that a simple calculation is performed. The correction amount of the delay amount can be calculated with.

Furthermore, in a system including a plurality of speakers, the delay amount set individually for each speaker is corrected according to the temperature detected by the temperature detecting means, so that the output from all the speakers is performed. The optimum delay amount is set for the played sound.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a diagram showing the entire structure of the sound reproducing system of this example. In the case of this example, the sound reproducing system is installed in a relatively large concert hall. In FIG. 1, 11 indicates a source as a sound source. This sauce 1
Examples of 1 may include some sound reproducing means (such as an audio reproducing device such as a CD player) and a microphone installed on the stage. Then, the acoustic signal supplied from the source 11 is converted into an analog / digital converter 1
2 and converts it into digital audio data. Then, the digital audio data output from the analog / digital converter 12 is supplied to the plurality of digital audio data processing circuits 13a, 13b ... 13n (n is an arbitrary number). Each of the digital audio data processing circuits 13a, 13b, ... The processing state is set.

Then, each digital audio data processing circuit 1
.. 13n are supplied to digital / analog converters 14a, 14b ..... 14n to be converted into analog acoustic signals, and these acoustic signals are respectively output amplifiers 15.
15n are supplied to the speakers 16a, 16b, ..., 16n arranged at predetermined positions in the hall through a, 15b ,.

The central control unit 21 of the present example is connected to an operation section 22 for setting the processing states of the digital audio data processing circuits 13a to 13n by key operation or the like. In addition, the microphone 2 installed near the listening position (that is, a predetermined seat) serving as the reference of this hall
The acoustic signal picked up by 3 is supplied to the central control unit 21 via the analog / digital converter 24.
Further, a temperature sensor 25 is provided in the vicinity of a listening position serving as a reference of this hole, and the detection data of the temperature sensor 25 is supplied to the central control unit 21 via the analog / digital converter 26. is there.

Then, in the central control unit 21, when initializing the processing state in the digital audio data processing circuits 13a to 13n, the acoustic signal supplied from the source 11 is supplied to each of the digital audio data processing circuits 13a to 13n. The central controller 2 detects the time difference between the timing at which the sound signal is picked up and the timing at which the acoustic signal picked up by the microphone 23 is supplied to the central controller 21 and the data of this time difference is collected.
The data is stored in the memory (not shown) in the memory 1. At this time, the temperature data of the listening position detected by the temperature sensor 25 is also stored at the same time.

When the system is operated, the digital audio data processing circuits 13a to 13n are operated by the time difference stored in the memory of the central controller 21.
The process of delaying digital audio data is performed.
However, since the installation positions of the speakers 16a to 16n are different, the delay amount is slightly corrected for each of the speakers 16a to 16n by operating the operation unit 22 according to the installation position. Up to this point, the initial settings are made.

When the sound reproducing system of this embodiment is used to actually reproduce a sound at a concert or the like, the temperature data of the listening position detected by the temperature sensor 25 is
The central control unit 21 makes a judgment every predetermined period (for example, every minute), and judges the difference between the current temperature and the temperature at the time of initial setting stored in the memory. Then, the amount of delay in each of the digital audio data processing circuits 13a to 13n is corrected in real time according to the determined temperature difference.

The correction process will be described below with reference to the flowchart of FIG. 2. First, the central controller 21 will be described.
The delay time data is input to (step 101), and the central controller 21 determines the detection data of the temperature sensor 25 at this time (step 102). And
Based on the input data, each processing circuit 13a to 13a
Set the optimum delay time for n (step 10
3). This corresponds to the initial setting.

When the sound reproducing system is operated after the initialization, the central controller 21 determines the data detected by the temperature sensor 25 (step 10).
4). Then, it is determined whether or not the temperature detected at this time has changed from the temperature detected at the time of initial setting (step 105). At this time, when the temperature is almost the same as the temperature at the time of initial setting, the operation is performed with the delay time as it is.

Then, when the temperature is changed from the temperature detected at the time of initial setting, the difference between the temperature at the time of initial setting and the current temperature is obtained, and the change in sound velocity corresponding to this temperature difference is calculated (step 106). Then, next, a change in the delay time corresponding to the calculated change amount of the sound velocity is calculated (step 10).
7). Then, by the calculated change amount of the delay time,
The delay amount in each of the digital audio data processing circuits 13a to 13n is corrected (step 108). Then, the processing from step 104 to step 108 is performed by the sensor 2
This is performed every time the temperature is detected in 5.

Here, an example of actually correcting the delay time will be described. For example, it is assumed that a delay time of 10 msec is set for the speaker system which is the initial setting. in this case,
It is assumed that the temperature at the time of initial setting is 10 ° C. The speed of sound in this state is calculated by the following equation.

[0026]

[Formula 1] 331.5 + 0.6 × 10 = 337.5 m / sec

If the temperature of the listening position during operation has risen to 25 ° C., the speed of sound at this time can be obtained by the following equation.

[0028]

[Expression 2] 331.5 + 0.6 × 25 = 346.5 m / sec

The time it takes for the sound to propagate at this speed of sound is 9.74.
In this case, the delay time is 0.26 msec, which is shorter than that in the initial setting.

By thus correcting the delay time in real time based on the temperature of the listening position, an accurate delay time is always set, and even if the temperature at the listening position changes, the sound source reproduces this system. It is possible to eliminate the time difference with the sound that reaches the listening position directly without going through. In particular, in a space such as a concert hall, there are large temperature changes depending on whether there are people in the seats or when there are empty seats, and the temperature changes greatly depending on the operating conditions of the air conditioning equipment. As a result, the timing difference between the direct sound and the reproduced sound felt by the person in the listening position can be almost completely eliminated at all times, and a great effect is brought about that natural sound reproduction can always be performed.

In this example, since the delay time is changed in each speaker system, the correction amount of the delay time due to the temperature change needs to be changed accordingly.
For example, a speaker installed near the stage in the audience is initially set to a delay amount of 10 msec, a speaker installed farthest from the stage is initially set to a delay amount of 20 msec, and a speaker closer to the stage is set by temperature correction. When the delay amount is reduced by 0.3 msec., Temperature correction is performed to reduce the delay amount by 0.6 msec. In the speaker farthest from the stage. However, the ratio of the delay amount to the correction amount is not always 1: 1 as in this case, and the correction state may be slightly changed depending on the acoustic characteristics of the hall in which the reproduction system is installed.

Further, here, the speakers 16a to 16n are provided.
Although the same sound is reproduced by the system (3), the sound of a different channel may be reproduced by each system (each channel) so that the stereophonic sound is reproduced in the hall.

Further, in the above-described embodiment, setting and correction of the delay amount in each of the digital audio data processing circuits 13a to 13n is performed.
Although the central control unit 21 that directly controls this processing circuit is controlled, a control signal such as a MIDI signal is externally supplied to the central control unit 21 to correct the delay amount due to the temperature change. May be. By doing so, it is possible to easily incorporate the temperature correction function of this example into a conventional sound reproduction system.

Further, in the above-mentioned embodiment, the temperature sensor is provided only at one place in the vicinity of the listening position, but the temperature sensor is provided at a plurality of places in the space where the sound is reproduced, and the temperature is detected on average. You may do it. Alternatively, a temperature sensor is provided in the vicinity of each speaker and the temperature of the sound reproduced from the speaker is corrected based on the temperature detected by the sensor in the vicinity, so that individual control for each reproduction system is performed. You can By doing so, even if there is a non-uniform temperature in the passenger seat, appropriate correction can be performed at each reproduction position.

Further, although the above-mentioned embodiment is applied to the sound reproduction system installed in the concert hall, it can be applied to various systems as long as it is a system reproduced in a relatively large space requiring delay processing.

[0036]

According to the present invention, the delay amount is corrected by the temperature in the vicinity of the listening position. Therefore, even if the temperature in the vicinity of the listening position changes, an appropriate delay amount is set and reproduced from the speaker. This has the effect that the timing of the sound and the timing of the directly arriving sound will always match at the listening position.

In this case, the delay amount is corrected based on the temperature difference between the temperature when the initial value of the delay amount is set and the current temperature detected by the temperature detecting means, so that a simple calculation is performed. The correction amount of the delay amount can be calculated with.

Furthermore, in a system including a plurality of speakers, the delay amount set individually for each speaker is corrected according to the temperature detected by the temperature detecting means, so that the output from all the speakers is performed. The optimum delay amount is set for the played sound.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing a delay time setting process according to an embodiment.

FIG. 3 is a configuration diagram showing an example of a conventional sound reproduction system.

[Explanation of symbols]

11 Sources 13a, 13b ... 13n Digital audio data processing circuit 16a, 16b ... 16n Speaker 21 Central control unit (CPU) 25 Temperature sensor

Claims (3)

[Claims] 1. A sound reproduction system in which delay processing is applied to an input sound signal and the sound is output from a speaker. Temperature detection means for detecting a temperature in the vicinity of a listening position, and delay according to the temperature detected by the temperature detection means. A sound reproduction system comprising a delay amount control means for correcting the amount. 2. The sound reproduction system according to claim 1, wherein the delay amount is corrected based on the temperature difference between the temperature when the initial value of the delay amount is set and the current temperature detected by the temperature detecting means. Sound reproduction system. 3. The sound reproduction system according to claim 1 or 2, further comprising a plurality of speakers, wherein a delay amount individually set for each speaker is determined according to a temperature detected by the temperature detecting means. Sound reproduction system with individual correction.