JP3500953B2 - Audio playback system setup method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a setup method and apparatus for a multi-channel type audio reproduction system.

[0002]

2. Description of the Related Art In a multi-channel type audio reproducing system, a surround processor as shown in FIG. 14 is used. In this processor, the input terminal 60 to which the encoded acoustic signal is input,
A multi-channel decoder 61 that extracts original multi-channel audio signals from the encoded audio signals and outputs the audio signals to a plurality of channels, and the audio signals of each channel can be independently and separately delayed, and Delay time setting device 62 with adjustable delay time
A level adjuster 63 capable of independently adjusting the levels of the audio signals of the respective channels and a master volume 64 capable of adjusting the levels of the audio signals of all the channels are connected in the order described above. Volume 64
Speakers are connected to the respective channels. As the encoded audio signal, an audio signal from a multi-channel source (for example, Dolby (trademark) surround or Dolby Digital) is encoded into a 2-channel signal or a bit stream signal.

When setting up the above audio reproduction system, the listening sound pressure level of the listener regarding the sound output of each speaker is made to coincide with the arrival time until the acoustic output of each speaker reaches the listener. is important.

By the way, conventionally, at the time of the above adjustment, a test signal is sequentially supplied to each channel to reproduce the test signal from each speaker, and the sound pressure level of each speaker at the listener position (listening position) is The level of the acoustic signal of each channel is adjusted by the level adjusting device 63 so that the sound pressure levels match each other, as measured by an auditory sense or a sound pressure meter.

During the above adjustment, the distance from the listener position to each speaker is measured, and the delay time setting device 6
2, the delay time of the acoustic signal of the other channel is adjusted with reference to the channel of the speaker having the largest distance. However, this is inefficient, so a microphone that outputs a speaker signal corresponding to the acoustic output of the speaker is installed at the listener position, and the arrival time from this speaker signal until the acoustic output of each speaker reaches the listener. Has been proposed, in which the delay time setting device 62 is operated to automatically match the arrival times.

[0006]

By the way, in the above-mentioned prior art, since the above-mentioned adjustment is performed separately, there is a problem that the setup efficiency is poor.

It is an object of the present invention to provide an audio reproduction system setup method and apparatus capable of solving the above problems.

[0008]

In order to achieve the above object, the present invention is characterized by a method of setting up an audio reproduction system, which is characterized in that a plurality of audio signal channels to which separate speakers are connected are provided. A setup method in an audio playback system capable of level adjustment and delay processing for each acoustic signal of a channel, in which a test signal is sequentially supplied to each channel and each speaker is sequentially made to output audio. , The speaker signal corresponding to the acoustic output of each speaker is output from the microphone at the listener position, and the settings for adjusting the level of the acoustic signal of each channel are performed so that the level of each speaker signal becomes approximately the reference level. Check the level value of the test signal supplied to the channel and the level value of each speaker signal. , Differentiation or difference, and based on the time when the differential value or the difference value becomes the maximum value and / or the minimum value, the arrival time until the acoustic output of each speaker reaches the microphone is obtained, and each arrival time is reached. The point is to set the delay processing of the acoustic signal of each channel so that the time becomes approximately the reference time. Further, the feature of the setup device of the audio reproduction system of the present invention is that
A plurality of audio signal channels connected to separate speakers, and a test signal supply means for sequentially and selectively supplying a test signal to each channel during setup,
The level adjustment means that can adjust the level of the audio signal of each channel separately, and the delay time setting means that can delay the audio signal of each channel separately and that delay time can be set, at the time of setup, Each speaker
In a system in which each speaker sequentially receives a test signal and sequentially outputs a sound, and a microphone at the listener position outputs a speaker signal corresponding to the sound output of each speaker. A test signal level detecting means for detecting the level of the test signal supplied to each channel; A test signal processing means for differentiating or differentiating the level value of the test signal detected by the test signal level detecting means; A test signal time detection means for detecting a test signal supply time at which the differential value or the difference value output from the test signal processing means becomes the maximum value and / or the minimum value; Level measuring means for measuring the level of each speaker signal from the microphone; In parallel with the measurement by the level measuring means, a speaker signal level detecting means for detecting the level of each speaker signal from the microphone; Speaker signal processing means for differentiating or differentiating the level value of each speaker signal detected by the speaker signal level detecting means; The differential value or difference value output from the speaker signal processing means is the maximum value and / or
Or a speaker signal time detection means for detecting a sound output arrival time which is the minimum value, and H.264. Level adjusting control means for controlling the level adjusting means so that the level of each speaker signal measured by the level measuring means becomes approximately a reference level; The arrival time until the acoustic output of each speaker reaches the microphone is calculated based on the test signal supply time detected by the test signal time detection means and the acoustic output arrival time detected by the speaker signal time detection means. Computing means; The point is to have a delay time setting control means for controlling the delay time setting means so that each arrival time calculated by the calculation means becomes substantially the reference time.
The test signal supply means may have a test signal generator for generating a test signal and a channel switching means for switching a channel for outputting the test signal. In addition, the test signal generator, a noise generator that outputs a noise signal while randomly changing the frequency, and a band limiting filter that limits the frequency band of the noise signal,
There may be a connecting means for connecting the band limiting filter to the channel switching means when the test signal first exceeds the reference level from the start of supply . In addition, the test signal generator outputs a noise signal while randomly changing the frequency, a band limiting filter that limits the frequency band of the noise signal, and a band limiting for a reference time from the start of the test signal supply. It may have an amplifier that brings the output signal level of the filter above the steady state level. Also, the test signal is supplied and opened.
When the level exceeds the reference level for the first time from the beginning , the amplifier is checked.
It may have a connecting means for connecting to the channel switching means . Furthermore, the test signal generator has a noise generator that outputs a noise signal while randomly changing the frequency, a band-limiting filter that limits the frequency band of the noise signal, and a level higher than the level of the noise signal. A pulse generator that outputs a rectangular pulse signal,
The supply start time of the test signal, channel pulse generator
Channel connection means, and then connect the band limiting filter to the channel.
There may be a switch means connected to the channel switching means . Further, the characteristics of the test signal level detecting means and the speaker signal level detecting means may be substantially the same. Further, the level measuring means is a level detecting means for detecting the level of the speaker signal, and each level detecting means has a signal squaring circuit for squaring the input signal and a smoothing circuit connected to the output side of the circuit. There is also. Also, the signal squaring circuit of the level measuring means and the speaker signal level detecting means may be common, and the smoothing circuits of both means may be separate.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings of FIGS. 1 to 13. FIG. 1 shows an outline of a multi-channel audio reproducing system, which has a surround processor and a setup device. .

First, the surround processor will be described. In this processor, an original multi-channel acoustic signal is extracted from the encoded acoustic signal to an input terminal 1 to which the encoded acoustic signal is input, and the surround signal is divided into a plurality of channels. A multi-channel decoder 2 that outputs an acoustic signal, and a delay time setting device (delay time setting means) 3 that can independently delay the audio signals of the respective channels and that can adjust the delay time thereof
, A level adjusting device (level adjusting means, gain adjusting means) 4 capable of independently and independently adjusting the level of the acoustic signal of each channel, and a master volume 5 capable of adjusting the levels of the acoustic signals of all channels in conjunction with each other. Are connected in the above order, and a speaker 7 is connected to each channel of the volume 5 via an amplifier 6.

The setup device matches the listening sound pressure level of the listener regarding the sound output of each speaker 7 and the arrival time until the sound output of each speaker 7 reaches the listener. Explaining in detail, 9 is a test signal supply means for selectively and sequentially supplying a test signal to each channel, which comprises a test signal generator 10 and a channel switching means 11.

The test signal generator 10 generates a band-limited random noise signal or the like as in the conventional case. The test signal generator 10 is, for example, (1) as shown in FIG. A signal is a noise signal, and a noise generator 13 that outputs a noise signal while randomly changing the frequency, and a band limiting filter 14 that limits the frequency of the noise signal within a predetermined band
(2) As shown in FIG. 3, in the configuration of (1) above,
A reference (predetermined) time from the start of supplying the noise signal, for example,
Make the noise signal level higher than the average level of the noise signal in the steady state only for a few msec (see Fig. 4).
(3) As shown in FIG. 5, the amplifier 16 is added to the configuration of (1) above.
A pulse generator 18 that outputs a rectangular pulse signal (see FIG. 6) whose level is higher than that of the noise signal;
Turn off the noise generator 13 and pulse generator 18
A switch means 19 which is selectively connected to the exchange means 11 and outputs a rectangular pulse signal prior to the noise signal for a reference (predetermined) time, for example, several msec from the start of supplying the test signal ( Instead of a rectangular pulse signal, a signal whose level exponentially attenuates or a frequency of 1K
A sinusoidal signal with several cycles on the order of Hz may be used. ) Etc. are used.

The test signal used is originally
Those satisfying the following requirements are preferable. That is, when matching the listener's listening sound pressure level regarding the sound output of each speaker 7, the test signal used is the effect of room reflection, standing wave, and the peak or dip of the frequency characteristics of each speaker 7. In order to make it hard to receive, it is preferable to use a band-limited random noise having an appropriate bandwidth and having a non-repetitive waveform, and to have less temporal level fluctuation.

On the other hand, when matching the arrival time until the sound output of each speaker 7 reaches the listener,
The test signal used is preferably a signal whose level changes as rapidly as possible, such as an impulse signal, in order to improve time resolution. In order to meet this requirement, for example, in the test signal generator 10 of (1) (2), band-limiting filter 14, or the output signal of the amplifier 16, i.e., test signals, shown in FIG. 7 So that the supply is open
First threshold level (reference level, the predetermined level) from the beginning when it becomes more, Cha band limiting filter
The connection means 17 (see the phantom line in FIGS. 2 and 3) for connecting to the channel switching means 11 may be provided.

In order to satisfy all the above requirements, the test signal generator 10 of (2) and (3) above is preferable.

The channel switching means 11 sequentially switches the channels from which the test signal from the test signal generator 10 is output, and has an input terminal 11A connected to each input channel to the delay time setting device 3 and each channel. Terminal 11A
, A selection switch section 11B for selectively connecting the output terminals of the test signal generator 10, a connection terminal 11C connected to each of the input terminals 11A, and a selection switch section 11B selectively connected to each of the connection terminals 11C. It has an interlock switch section 11D and the like interlocking with.

Reference numeral 21 is a test signal level detecting means (test signal detecting means) for detecting that the test signal is supplied to each channel, that is, for detecting the level of the test signal supplied to each channel. , And is connected to the interlocking switch section 11D to input a test signal. The test signal level detecting means 21 has a differentiating (difference) processing unit (processing means, differentiating) of the output value of the detecting means.
Processing circuit 22 and a test signal maximum (small) time detection unit (maximum value time, minimum value time) for detecting a test signal supply time (maximum value time, minimum value time) at which the differentiated (difference) value becomes a maximum value and / or a minimum value. (Detection means, detection circuit) 23 are connected in the above order.

Reference numeral 25 denotes a microphone, which receives the acoustic output from each speaker 7, outputs a speaker signal corresponding to the acoustic output of each speaker 7, and the speaker signal is amplified by the amplifier 26.

Reference numeral 27 is a speaker signal first level detecting means (level measuring means) and 28 is a speaker signal second level detecting means (speaker signal detecting means) for detecting the level of the speaker signal. Although connected to the amplifier, the characteristic of the second level detecting means 28 is (substantially) the same as the characteristic of the test signal level detecting means 21. The second level detection means 28 has a differentiation (difference) processing unit (processing means, processing circuit) 29 that differentiates (differences) the output value of the detection means, and the differentiated (difference) value is the maximum value and / or The speaker signal maximum (small) time detection unit (detection means, detection circuit) 30 for detecting the minimum acoustic output arrival time (maximum time, minimum value time) is connected in the above order.

32 is a microcomputer (system controller,
Control means), the microcomputer 32 controls the first level detection means 2
A memory for measuring the level value of the speaker signal from the output of 7 and storing the level value, the test signal supply time and the sound output arrival time detected by the maximum (small) time detection units 23 and 30 in the microcomputer 32. A device 33 is provided,
Moreover, by the microcomputer 32, the multi-channel decoder 2, the delay time setting device 3, the level adjusting device 4, the master volume 5, the test signal supplying means 9, the test signal level detecting means 21, the first and second level detecting means 2 are provided.
7, 28, etc. are controlled. Further, the microcomputer 32 is also connected to display means (for example, a display, a speaker, etc.) 34 for outputting video or audio.

An outline of the control of the above configuration example will be described. Under the control of the microcomputer 32, the test signal is sequentially supplied from the test signal supply means 9 to each channel, and sequentially output from each speaker 7 as an acoustic output. , Is input to the microphone 25 at the listener position. The microphone 25 outputs a speaker signal corresponding to the acoustic output, which is amplified by the amplifier 26 and input to the first and second level detecting means 27, 28. Further, the test signal is input to the test signal level detecting means 21 via the channel switching means 11.

When switching the channel to which the test signal is input by the channel switching means 11, a predetermined rest period is required. The reason is that the delayed sound output (voice) before the channel switching may adversely affect the level detection and measurement of the speaker signal after the channel switching. In a general listening environment,
It is unlikely that the distance from each speaker 7 to the listener exceeds 10 m. Since the sound travels a distance of 10 m for about 30 ms, the rest period is 5
0 ms to 100 ms is sufficient.

When matching the listening sound pressure levels of the listeners with respect to the sound output of each speaker 7, first, the level of the speaker signal is measured. At this time, a reference (predetermined, set) time (for example, several seconds, or the first level detecting means 2) from the time when the test signal is supplied to the channel.
When 7 is composed of a signal squaring circuit for squaring the input signal and a low pass filter (smoothing circuit) for smoothing the output of the circuit, several times the time constant of the low pass filter)
After a lapse of time, after the output of the first level detecting means 27 stabilizes, the output value of the first level detecting means 27 is directly used as the level value of the speaker signal. When the output value of is sampled at regular intervals and the change in the output value falls within the standard (predetermined, setting) range (for example, within several percent),
There is a case where the output value is used as the level value of the speaker signal. In general, this detection level value is not used as it is, but in many cases, the detection level value is logarithmically converted into a format having a correlation with decibels.

Then, the microcomputer 32 compares the detection level value with a reference level value (setting value, predetermined value),
The excess or deficiency of the level (gain) of the acoustic signal of each channel is calculated, and the level adjustment device 4 adjusts (sets) the level of each channel. The reference level value is
If the level value corresponds to the reference sound pressure level value at the listener position (in this case, at least before the test,
The level adjusting device 4 and the master volume 5 need to be set to default positions, and the average value of all detection level values may be used as the reference level value (in this case,
At least the level adjuster 4 must be set to the default position before the test). In the above case,
The microcomputer 32 determines whether or not the detection level value is within the reference range. If the detection level value is within the reference range, the operation is continued. If the detection level value is outside the reference range, the operation is stopped. After that, the test signal supply means 9 repeatedly supplies the test signal to the current channel,
When the number of repetitions reaches the reference number, the display means 3
In some cases, a message is output from 4 and all operations are stopped.

Next, when matching the arrival time until the sound output of each speaker 7 reaches the listener, first,
It is necessary to measure the arrival time at which the acoustic output of each speaker 7 reaches the listener position. This measurement is, for example,
The procedure is as follows.

That is, at the time of measuring the arrival time, when the test signal is supplied to one channel and / or when the supply is stopped, the test signal level detecting means 21 and the second level detecting means 28 detect the test signal. And a sudden change in the level of the speaker signal is detected. By the way, in the above case, the detection accuracy can be improved by performing a kind of level expansion for each signal by the test signal level detection means 21 and the second level detection means 28. This level expansion processing can be achieved by using a signal square circuit generally required for RMS (effective value) measurement as described below.

For example, when the second level detecting means 28 is composed of a signal squaring circuit for squaring the speaker signal and a low pass filter (smoothing circuit) to which the output of the circuit is inputted, the speaker is provided in the microphone 25. When the sound output of FIG.
As shown in, the speaker signal is output. The signal squaring circuit squares the speaker signal as shown in FIG. 8 (B), which is smoothed by a low pass filter as shown in FIG. 8 (C) and then differentiated (difference). Processing unit 29
Are differentiated as shown in FIG. Then, by the maximum (small) time detection unit 30, the maximum value time t (max) at which the differentiated value becomes the maximum value max and / or the minimum value time t at which the differentiated value becomes the minimum value min.
(Min) is detected.

Then, similarly to the above, the test signal is also differentiated to detect the maximum value time when the differential value becomes the maximum value and / or the minimum value time when the differential value becomes the minimum value,
For example, the maximum value time regarding the test signal is regarded as the test signal supply time, the maximum value time regarding the speaker signal is regarded as the acoustic output arrival time from the speaker 7 to the listener, and the arrival time is calculated from the difference between the two maximum value times. .
The arrival time may be calculated from the minimum value time or the average value of the maximum value time and the minimum value time.

At the time of measuring the time, a counter may be used to give a constant clock and the time may be calculated from the counted number. Especially, in the case of the processing by the digital signal processor (DSP) described below. Alternatively, the time may be measured by counting its built-in clock or the L / R clock used in the A / D converter or the D / A converter. In short, you can use anything that correlates with the actual time (hours, minutes, seconds).

In the above case, the microcomputer 32 determines whether or not the measured arrival time is within the reference range. If the arrival time is within the reference range, the operation is continued and the arrival time is reached. If it is out of the reference range, after the pause, the test signal supply means 9 repeatedly supplies the test signal to the current channel, and when the number of repetitions reaches the reference number, a message is output from the display means 34. Then, all the operations may be stopped.

By the way, in the measured arrival time, in addition to the arrival time of the sound output of each speaker 7 reaching the microphone 25 at the listener position, a signal until the test signal is input from the channel switching means 11 to the speaker 7 is obtained. The delay time for processing and the delay time for signal processing until the speaker signal of the microphone 25 is processed and output from the maximum (small) time detection unit 30 are included, which is an error ( In particular, when the above processing is digitally processed, a digital filter, D / A converter, A
There is also a delay time due to signal processing of the / D converter, etc.).

However, since the test signal level detecting means 21 for detecting the level of the test signal and the second level detecting means 28 for detecting the level of the speaker signal have (substantially) the same characteristics, the delay time is within the above delay time. The delay time due to the signal processing of the test signal level detecting means 21 and the speaker second level detecting means 28 is canceled, no error occurs, and the accuracy of arrival time measurement can be improved. Further, as described below, when matching the arrival time until the acoustic output of each speaker 7 reaches the listener, the maximum one of the measured arrival times is set as the reference time, and the other arrival times are set. Since the relative difference between the reference time and the reference time is taken, the above error does not affect the actual delay time setting of each channel.

After measuring the arrival time at which the acoustic output of each speaker 7 reaches the listener position as described above,
When matching the arrival time until the acoustic output of each speaker 7 reaches the listener, the maximum one of the above-mentioned measured arrival times is set as a reference time, and the difference between this and other arrival times is taken into consideration. The delay time of each channel is set by the delay time setting device 3, and the arrival time until the acoustic output of each speaker reaches the listener is matched.

At the time of the above setup, a method of supplying a test signal to each channel once, adjusting the level of each channel and setting a delay time, and then terminating,
After the above work, either the method of supplying the test signal to each channel again for confirmation or the method of supplying the test signal to each channel repeatedly until the level adjustment and delay time setting of each channel can be done well. Is selected.

FIG. 9 shows the setup device shown in FIG.
It is composed of SP and will be described below. First, a preamplifier 36 is used as the amplifier 26 of FIG.
The output of the amplifier 36 is input to the first and second level detecting means 27, 28 via the A / D converter 37.

Further, each level detecting means 21, 27, 27 of FIG.
28 is a signal squaring circuit 3 for squaring the input signal.
8, 39 and low pass filters (LPF, smoothing circuits) 40, 41 for smoothing the output signals of the circuits 38, 39,
Although it is composed of 42, the signal square circuit 39 of the first and second level detecting means 27, 28 is common. Since it is desirable that the output of the first level detecting means 27 fluctuate as little as possible in order to measure the level of the speaker signal, the time constant of the low-pass filter 41 of the first level detecting means 27 is set to be large. , And is almost the same as the time constant of the sound level meter (about 1.5 seconds).

On the other hand, in order to measure the arrival time, the output fluctuations of the test signal level detecting means 21 and the second level detecting means 28 need to be large to some extent.
The time constants of these low-pass filters 40 and 42 are (substantially) the same, and are set smaller than the time constant of the low-pass filter 41 of the first level detecting means 27. When the test signal generator 10 is constructed as shown in FIG. 3, the time constant when the level of the test signal returns to the steady state is determined by the low pass filter of each level detecting means 21, 27, 28. The time constant is set to 40 or 41 or 42 or less.

The differential (difference) processing units 22 and 29 shown in FIG.
As difference processing means (processing unit, processing circuit) 44, 4
5 is used, and further, the maximum (small) time detection unit 2 in FIG.
Maximum (small) value determination means (determination section, determination circuit) 46 and 47 are used as 3, 30 and outputs thereof are once
It is input to the counter device 48. Counter device 48
Has a first counter 49 for latching the outputs from the maximum (small) value judging means 46, 47, and a second counter 50 for transferring the latched output to the first counter 49 and outputting it to the microcomputer 32 side. , Counter device 4
The L / R clock is input to the 8 from the A / D converter 37.

Next, the control of the level measurement of each speaker signal will be described based on the flowchart shown in FIG. 10. In step S1, the microcomputer 32 supplies the test signal to the n-th channel by the test signal generator 10 and the test signal generator 10. After instructing the channel switching means 11, step S2
Move on to. In step S2, the output from the low-pass filter 41 of the first level detecting means 27 for level setting, that is, the level value of the speaker signal is set at a constant interval (for example, 2).
0 ms), the value is read into the microcomputer 32, the value read in the kth time is set to X (k), and the process proceeds to step S3.

In step S3, it is determined whether or not the elapsed time from the start of supplying the test signal exceeds a reference (predetermined, set) time (for example, several seconds). If YES, the process moves to step S12, and if NO, the process moves to step S4. In step S4, it is determined whether or not the level value of the speaker signal is increasing. This is to determine whether or not the level value of the speaker signal is measured in a stable state. For example, X (k)> X (k-1)> X.
If (k-2), the process proceeds to step S5, and if NO, the process returns to step S2 and the level value of the speaker signal is read into the microcomputer 32 again.

In step S5, X (k), X (k-
1) and X (k-2), it is determined whether or not an arbitrary two difference is smaller than a reference (predetermined, set) value. For example, | X (k) -X (k-1) | <e, | X (k-1)
-X (k-2) | <e, | X (k) -X (k-2) | <
It is determined whether all of e are satisfied. this is,
This is to judge the variation of the level value of the speaker signal.
Usually, the above e is set so that the difference between the level values is within several percent. If YES in step S5, the process proceeds to step S6, and if NO, the process returns to step S2.

In step S6, X (k), X (k-
1), the average value Y (n) of X (k-2), that is, Y (n)
= [X (k) + X (k-1) + X (k-2)] / 3 is obtained, and the process proceeds to step S7. As described above, Y
The reason why (n) is the average value is to improve the measurement accuracy by averaging the variations in the level value of the speaker signal at the time of measurement. However, Y (n) is not the average value and a single value is used. It may be a level value.

In step S7, it is determined whether or not the average value Y (n) is larger than the maximum limit (for example, a value which is 10 dB higher than the reference value). If YES, the process moves to step S11, and if NO, the process moves to step S8. In step S8, it is determined whether or not the average value Y (n) is smaller than a minimum value (for example, a value that is a few ten dB below the reference value). If YES, the process moves to step S9, and if NO, step S9
Go to 10.

In step S9, n and Y (n) are stored,
That is, the test signal is stored in the storage device 33 and the test signal is supplied to the next channel, or the process is terminated. Also, steps S9 and S1
In 1 and S12, error processing 1 to 3 is performed, respectively, and the display unit 34 outputs an error message in audio or video, and returns to step S1 again, or
Exit or change the test signal level,
Control is performed such as re-measurement or determining that there is no speaker and moving to the next channel. The error processing is performed as described above in order to prevent an abnormal level adjustment or the like due to a user's installation error of the audio reproduction system.

Next, the control of the level adjustment of the acoustic signal of each channel will be described with reference to the flowchart shown in FIG. 11. In step T1, Y (n) stored in the storage device 33 as the level value of the nth channel. Read
Move to step T2. At step T2, Z (n) = 1
0.log [Y (n)] is calculated, and the process proceeds to step T3. In step T3, the decibel (dB) difference A (n) from the reference value (specified value, predetermined value, set value) is A (n) = B
-Z (n) is obtained, and the process proceeds to step T4. In step T4, the level adjustment device 4 adjusts the level adjustment of the nth channel to + A (n), and then adjusts the level of the next channel or terminates the control.

Next, based on the flowchart of FIG.
The control of the measurement of the arrival time at which the sound output of each speaker reaches the listener position will be described. First, in step R1, the microcomputer 32 supplies the test signal to the n-th channel to generate the test signal generator 10 and the channel switching means 11. And then move to step R2. At step R2, the first and second counters 49 and 50 are reset, and the routine proceeds to step R3. In step R3, L / R
Judge whether the rising edge of the clock has changed, Y
If ES, the process proceeds to step R4, and if NO, the process returns to step R3.

At step R4, the value of the first counter 49 is incremented by 1, and the process proceeds to step R5. At step R5, it is judged whether or not the difference output of the difference processing means 44 for the test signal is larger than the difference output before that. This is to identify the rising time of the test signal,
If YES, then go to Step R6, and if NO:
Move to step R7. In step R6, the first and second counters 50 are reset, and the process proceeds to step R7.

At step R7, it is judged whether or not the difference output of the difference processing means 45 for the speaker signal is larger than the previous difference output. This is to specify the rising time of the speaker signal, and if YES, the process proceeds to step R8, and if NO, the process proceeds to step R9.
In step R8, the value of the first counter 49 is output to the second counter 50, and the process proceeds to step R9.

In step R9, it is determined whether or not a reference time, for example, 0.1 seconds has elapsed since the supply of the test signal was stopped. If YES, the process proceeds to step R10 and NO.
If so, the process returns to step R3. In step R10,
The value of the second counter 50 is output to the microcomputer 32 as the arrival time and stored in the storage device 33, and then the test signal is supplied to the next channel or the control is ended.

Next, based on the flowchart of FIG.
Match the arrival time until the sound output of each speaker 7 reaches the listener (setting of delay time of each channel)
The control will be described. In step U1, the maximum arrival time is selected from the arrival times stored in the storage device 33, and is set as the maximum arrival time Tmax.
Move to 2. In step U2, the difference between the maximum arrival time Tmax and the arrival time of the n-th channel is calculated, and this is D (n)
Then, the process proceeds to step U3. In step U3, the delay time setting device 3 sets the delay time of the nth channel to the above D (n) and sets the delay time of the next channel, or the control ends.

To explain the above control in detail, the channel switching means 11 selects a specific channel according to an instruction from the microcomputer 32, and a test signal is input to the channel from the test signal generator 10. Is
It is supplied to the speaker 7 via the delay time setting device 3, the level adjusting device 4, and the master volume 5, and the speaker 7 outputs a sound. Further, the test signal is input to the signal squaring circuit 38 of the test signal level detecting means 21, squared, smoothed by the low-pass filter 40, and then subjected to difference processing by the difference processing means 44 to obtain the maximum value and The minimum (or minimum) value is judged by the maximum (small) value judging means 46, and the judged value is latched in the first counter 49.

On the other hand, the acoustic output of the speaker is input to the microphone 25, and the microphone 25 outputs the speaker signal corresponding to the acoustic output, which is the preamplifier 3.
6 is amplified by the A / D converter 37,
The signal is squared by being input to the signal squaring circuit 39 of the second level detecting means 27, 28. The output of the signal square circuit 39 is smoothed by the low-pass filter 41, and the microcomputer 32
Is measured, the level of the speaker signal is measured, and is stored in the storage device 33. The output of the signal square circuit 39 is also smoothed by the low-pass filter 42, subjected to difference processing by the difference processing means 45, and its maximum value and / or minimum value is judged by the maximum (small) value judgment means 47. Then, the determination value is latched in the first counter 49.

As described above, each judgment value latched by the first counter 49 is input to the microcomputer 32 through the second counter 50, and from each judgment value, as in the case shown in FIG. After the arrival time at which the acoustic output of the speaker reaches the listener position is calculated, this arrival time is stored in the storage device 33.

Regarding the level adjustment of each channel, the microcomputer 32 compares each level value stored in the storage device 33 with the reference value, calculates the excess / deficiency of the level value of each channel, and adjusts the level. The level of each channel is adjusted by the device 4.

Regarding the delay time setting for each channel, the microcomputer 32 sets the maximum one of the arrival times stored in the storage device 33 as the reference time, and the difference between this and other arrival times is The delay time of the corresponding channel is set by the delay time setting device 3.

[0056]

As described in detail above, according to the present invention,
Delay time for each channel to adjust the level of each channel to match the listener's listening sound pressure level with respect to each speaker's acoustic output and to match the arrival time of each speaker's acoustic output to reach the listener Since setting can be done at the same time, setup can be done efficiently and easily.

According to the other claims, the following effects can be obtained. According to claims 4 to 7, since the test signal level abruptly changes immediately after the start of supplying the test signal, the test signal and the speaker signal can be detected with high accuracy, and the acoustic output of each speaker reaches the listener position. The arrival time can be measured with high accuracy. According to the eighth aspect, since the delay time of the signal processing of the test signal detecting means and the second level detecting means is canceled when the arrival time is measured, the arrival time measurement accuracy can be improved. According to the tenth aspect, since the signal square circuit of the first and second level detecting means is common, the circuit can be simplified accordingly.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing an example of an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of the test signal generator of FIG.

FIG. 3 is a block diagram showing an example of the test signal generator of FIG.

4 is a waveform diagram of a test signal of the test signal generator of FIG.

5 is a block diagram showing an example of the test signal generator of FIG. 1. FIG.

6 is a waveform diagram of a test signal of the test signal generator of FIG.

FIG. 7 is a waveform chart showing signal processing of the maximum (small) time detection unit in FIG.

FIG. 8 is a waveform diagram showing the output timing of the test signal of FIG.

FIG. 9 is a specific example of a part of FIG.

FIG. 10 is a flowchart showing an example of an embodiment of the present invention.

FIG. 11 is a flowchart showing an example of an embodiment of the present invention.

FIG. 12 is a flowchart showing an example of an embodiment of the present invention.

FIG. 13 is a flowchart showing an example of an embodiment of the present invention.

FIG. 14 is a block diagram showing a general surround processor.

[Explanation of symbols]

3 Delay time setting device 4 level adjuster 7 speakers 9 Test signal supply means 10 Test signal generator 11 Channel switching means 21 Test signal level detection means 25 microphone 27, 28 First and second level detecting means 32 microcomputer 38, 39 Signal Square Circuit 40, 41, 42 low pass filter

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04S 7/00 H04S 5/02

Claims (10)

(57) [Claims] 1. A setup method in an audio reproduction system comprising a plurality of audio signal channels to which separate speakers are connected, and capable of level adjustment and delay processing for the audio signals of each channel respectively. A test signal is sequentially supplied to each channel, and each speaker is sequentially output as a sound, and a speaker signal corresponding to the sound output of each speaker is output from the microphone at the listener position. To be at the reference level,
The settings related to the level adjustment of the acoustic signal of each channel are performed, and the level value of the test signal supplied to each channel and the level value of each speaker signal are respectively differentiated or differentiated to obtain the differentiated value, or Based on the time when the difference value becomes the maximum value and / or the minimum value, the arrival time until the acoustic output of each speaker reaches the microphone is obtained, and the acoustic signal of each channel is set so that each arrival time becomes approximately the reference time. A method for setting up an audio playback system, characterized in that settings related to delay processing are performed. 2. A plurality of audio signal channels connected to separate speakers, a test signal supply means for sequentially and selectively supplying a test signal to each channel at the time of setup, and an audio signal level of each channel is separated. Has a level adjusting means that can be adjusted to and a delay time setting means that can delay the audio signal of each channel separately and can set the delay time. In response to the supply, each speaker sequentially outputs a sound, and the microphone at the listener position outputs a speaker signal corresponding to the sound output of each speaker. A test signal level detecting means for detecting the level of the test signal supplied to each channel, and B. A test signal processing means for differentiating or differentiating the level value of the test signal detected by the test signal level detecting means; A test signal time detection means for detecting a test signal supply time at which the differential value or the difference value output from the test signal processing means becomes the maximum value and / or the minimum value; Level measuring means for measuring the level of each speaker signal from the microphone; E. In parallel with the measurement of the level measuring means, speaker signal level detecting means for detecting the level of each speaker signal from the microphone, and F. Speaker signal processing means for differentiating or differentiating the level value of each speaker signal detected by the speaker signal level detecting means, and G. Speaker signal time detection means for detecting the differential value output from the speaker signal processing means or the acoustic output arrival time at which the difference value becomes the maximum value and / or the minimum value; Level adjusting control means for controlling the level adjusting means so that the level of each speaker signal measured by the level measuring means becomes substantially a reference level; The arrival time until the acoustic output of each speaker reaches the microphone is calculated based on the test signal supply time detected by the test signal time detection means and the acoustic output arrival time detected by the speaker signal time detection means. Computing means; An apparatus for setting up an audio reproduction system, comprising: a delay time setting control means for controlling the delay time setting means so that each arrival time calculated by the calculation means becomes substantially a reference time. 3. The test signal supply means has a test signal generator for generating a test signal and a channel switching means for switching a channel for outputting the test signal.
Setup device for the described audio playback system. 4. A test signal generator, a noise generator that outputs a noise signal while randomly changing a frequency, a band-limiting filter that limits the frequency band of the noise signal, and a test signal that is the first reference from the start of supply. The set-up device for an audio reproduction system according to claim 3, further comprising connecting means for connecting the band-limiting filter to the channel switching means when the level exceeds the level. 5. A test signal generator, a noise generator that outputs a noise signal while randomly changing the frequency, a band limiting filter that limits the frequency band of the noise signal, and a reference time from the start of supplying the test signal. 4. The set-up device for an audio reproduction system according to claim 3, further comprising an amplifier that makes the level of the output signal of the band-limiting filter larger than the level in the steady state. 6. The set-up device for an audio reproducing system according to claim 5, further comprising connecting means for connecting the amplifier to the channel switching means when the test signal first exceeds a reference level from the start of supply . 7. The test signal generator comprises: a noise generator that outputs a noise signal while randomly changing the frequency; a band limiting filter that limits the frequency band of the noise signal; and a level higher than the level of the noise signal. a pulse generator for outputting a square pulse signal with, at the start the supply of the test signal, Chan pulse generator
After connecting to the channel switching means, Cha band limiting filter
4. The audio playback system setup device according to claim 3, further comprising switch means connected to the channel switching means . 8. The characteristics of the test signal level detecting means and the speaker signal level detecting means are substantially the same.
7. The setup device for an audio playback system according to any one of 7 to 7. 9. The level measuring means is a level detecting means for detecting the level of a speaker signal, and each level detecting means has a signal squaring circuit for squaring an input signal and a smoothing circuit connected to the output side of the circuit. 9. A setup device for an audio reproduction system according to claim 2, further comprising: 10. The set-up device for an audio reproducing system according to claim 9, wherein the signal-square circuit of the level measuring means and the level detecting means for the speaker signal are common, and the smoothing circuits of both means are separate.