JPH10228286A - Sound field compensating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the time required for the compensating operations by reducing the digital.signal.processor(DSP) setting change time and to provide an optimum sound field compensation by using a computation control means which has a superior computational capability to execute the parameter computations for a sound field compensation. SOLUTION: A personal computer 5 executes the setting changes of a DSP 43 which computes the arithmetic parameters to vary acoustic process characteristics. In other words, the computer 5 computes the acoustic process parameters to realize objective sound field characteristics from measured sound field characteristics for the voices outputted from a voice output section through the acoustic process of a compensation acoustic processing means (a PC board 6) during a compensation operation and the board 6 executes the acoustic process. If the objective sound field characteristics are made coincide with the measured sound field characteristics, the sound field compensation is conducted by setting the acoustic process parameters used in the board 6 into the acoustic processing means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for correcting a sound field characteristic of an output of music or the like.

[0002]

2. Description of the Related Art As a unit for performing sound field correction using a DSP (DIGITAL SIGNAL PROCESSER) as a sound processing apparatus, there is, for example, a digital preamplifier unit. In sound field correction, for example, characteristics (such as frequency characteristics) obtained when sound output from a speaker is collected at a certain point,
This is an operation of adjusting the parameters of the acoustic processing so as to match a certain target characteristic. In the case of a digital preamplifier unit, a combination of signal processing parameters calculated in advance by a personal computer, a workstation or the like is held as table data in a memory unit inside the digital preamplifier unit. When the setting of the sound processing characteristics of the DSP is changed for sound field correction, direct memory access (DMA) from the memory to the DSP is performed.
And so on.

[0003] The reason why the table data is held in this way is to eliminate the burden of parameter calculation. That is, the calculation of the parameters for acoustic processing requires an enormous amount of calculation, and therefore cannot be practically calculated by a microcomputer mounted on the digital preamplifier unit. Therefore, by holding various parameters as calculation results, it is possible to cope with a change in the setting of the acoustic processing characteristic for realizing the target sound field characteristic. Also, DSP
While the processing parameters are being changed in step (1), the audio signal output is stopped (muted), and the reproduced audio output from the speaker is silenced.
By transferring, the processing time for the parameter set can be shortened, and the time when the user feels that the sound is cut off can be shortened.

[0004]

However, with such a method, it is naturally impossible to make settings other than those that can be realized by a combination of operation parameters prepared in advance as table data. For this reason, optimal sound field correction cannot be executed in many cases. Accordingly, a system has been developed in which a personal computer or the like directly transmits operation parameters for acoustic processing to a unit that performs acoustic signal processing by a DSP or the like.

FIG. 5 shows a configuration example of such a system. The sound field correction unit 62 is a unit that performs sound signal processing with predetermined characteristics by a DSP, and the digital preamplifier unit or the like corresponds to this.

An audio signal to be processed by the sound field correction unit 62 is supplied from an audio signal source 61. Audio signal source is CD (compact disk) player, MD
(Mini-disc) Indicates a device serving as an audio signal source, such as a player, a tape player, and a tuner. The audio signal source 61 and the sound field correction unit 62 are connected by, for example, an optical transmission cable for audio, and an optical digital audio signal SOP is supplied from the audio signal source 61 to the sound field correction unit 62. The signal subjected to sound processing such as equalizing by the sound field correction unit 62 is an analog sound signal SA
And supplied to the power amplifier 63. The power amplifier 63 amplifies the supplied audio signal SA and outputs it from the speaker 64 as audio.

To execute the sound field correction processing for the above sound field forming system, a personal computer 67 is connected to the sound field correction unit 62 as shown in the figure. Further, a microphone 66 and a microphone input system 65 for actual sound field measurement are connected. In addition, the microphone input system 65 is
For example, an input circuit system of a sound collected by a microphone 66 such as a microphone amplifier or an A / D converter is referred to as a microphone input system 65.
Alternatively, it may be mounted inside the personal computer 67. The sound field correction unit 62 and the personal computer 67 are connected by, for example, a serial communication cable or a parallel communication cable during the execution of the correction operation, and are in a state where various kinds of communication can be performed.

In such a system, when performing a sound field correction, the personal computer 67 calculates necessary parameters. That is, in a state where the sound field correction unit 62 performs the sound processing with a certain combination of parameters and the signal is output from the speaker 64, the personal computer 67 determines the sound field characteristics of the sound collected by the microphone 66. To analyze.

[0009] From the analysis results of the current sound field characteristics,
A DSP processing parameter (filter operation coefficient, etc.) for realizing a certain target sound field characteristic is calculated and transmitted to the sound field correction unit 62 to be set. As a result, the sound field correction unit 62 sets a processing characteristic approaching the target sound field characteristic, and outputs a sound processed with the new processing characteristic from the speaker 64. Such a process is executed a required number of times, and when the analysis result of the sound field characteristics of the sound collected by the microphone 66 matches the target sound field characteristics, the sound field correction operation is completed.

According to such a system, since an external personal computer 67 having a high computing ability is used,
The optimum sound field adjustment can be realized. However, there is a problem in the communication capability between the personal computer 67 and the sound field correction unit 62. That is, in the case of a communication cable such as a serial communication cable or a parallel communication cable, a reduction in the communication speed is unavoidable due to the influence of external noise and restrictions on the cable length. For this reason, DSP setting changes (that is, transmission of processing parameters from the personal computer 67 to the sound field correction unit 62 and DSP
The time required for setting in the internal RAM) increases. In practice, it often takes about three minutes for the setting change process. Then, in the process of converging to achieve the desired sound field characteristics, the setting is changed many times.

During this setting change, the audio output is muted. Therefore, the user does not have to wait for about three minutes of silence every time the DSP setting is changed during the sound field correction. And the adjustment would take a very long time. In addition, the presence of the silent period of about 3 minutes before and after the DSP setting change also has a disadvantage that it is difficult for the user to perceive a subtle change in the sound field before and after the setting change.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has been made in view of both the problem that the correction operation can be shortened by shortening the DSP setting change time and that the optimum sound field correction can be performed. It is intended to be realized.

For this purpose, as a sound field correction device, at least at the time of a correction operation, it is possible to communicate with the sound processing means, and to perform setting control of sound processing characteristics in the sound processing means, The high-speed bus system enables communication with the control means, and can execute the same sound processing as the sound processing means, and
At least at the time of the correction operation, a sound signal from a sound signal source is input, sound processing is performed, and the sound signal is output from the sound output unit as a sound processing unit for correction that can output the sound signal as sound from the sound output unit. Measuring means for measuring a sound field characteristic of the voice. Then, at the time of the correction operation, the arithmetic control unit realizes the target sound field characteristic from the sound field characteristic measured by the measurement unit for the sound output from the audio output unit through the sound processing by the correction sound processing unit. For the correction, and causes the sound processing unit for correction to execute the sound processing based on the calculated sound processing parameters. Thereafter, when the sound field characteristics measured by the measurement unit match the target sound field characteristics, the sound processing parameters used in the correction sound processing unit at that time are set in the sound processing unit, Perform sound field correction.

That is, in the present invention, optimal sound field correction is performed by using arithmetic control means (for example, a personal computer) having a high calculation capability capable of executing parameter calculation for sound field correction. Further, during the correction operation, the setting processing is not performed for the sound processing unit that should actually change the setting, and the correction sound processing unit that can perform the same sound processing as the sound processing unit is not changed. To change the settings. This setting change is a setting change of a processing characteristic for approaching a target sound field characteristic. If the correction sound processing means is directly connected to the internal high-speed bus unit of the computer device, for example, in the form of an extension unit, the communication time for changing the setting of the sound processing characteristics can be significantly reduced. Then, after the optimal processing characteristics are obtained, a parameter set for the optimal processing characteristics may be executed on the acoustic processing device to be actually corrected.

[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 block diagram of a sound field forming system in a state where the sound field correction device of the present embodiment is connected. The sound field forming system includes an audio signal source 1, a sound field correction unit 2, a power amplifier 3, and a speaker 4.

The audio signal source 1 indicates a device serving as an audio signal source such as a CD (compact disk) player, an MD (mini disc) player, a tape player, a tuner, etc. The audio signal from the audio signal source 1 is a sound signal. The sound is processed by the field correction unit 2. Although the PC board 6 is interposed between the audio signal source 1 and the sound field correction unit 2 in FIG. 1, the PC board 6 is inserted into the audio signal path as illustrated when performing the sound field correction. Normally, the audio signal source 1 and the sound field correction unit 2 are connected by, for example, an optical transmission cable for audio. Therefore, the optical digital audio signal SOP is supplied from the audio signal source 1 to the sound field correction unit 2.

The signal subjected to sound processing such as equalizing in the sound field correction unit 2 is converted into an analog audio signal SA and supplied to the power amplifier 3. The power amplifier 3 amplifies the supplied audio signal SA and outputs it from the speaker 64 as audio.

When performing the sound field correction processing for the above sound field forming system, the PC board 6 as an extension unit of the personal computer 5 is connected to the sound signal source 1 and the sound field correction unit 2 as shown in the figure. Between the signal paths. The personal computer 5 and the sound field correction unit 2 are connected by a serial bus SB.

As a practical form, for example, if the sound field correction unit 2 is a digital preamplifier unit, a PC board connection terminal is provided in this digital preamplifier unit so that a signal path shown in the drawing can be formed. Further, the digital preamplifier unit is provided with a communication cable connection portion with the personal computer 5. Note that the connection between the sound field correction unit 2 (digital preamplifier unit) and the personal computer 5 may be a parallel bus.

For measuring the sound field characteristics, the microphone 7 is connected to, for example, a PC board. PC
The board 6 is directly connected to a high-speed bus system (PC bus interface) PB inside the personal computer 5 as an extension unit of the personal computer 5.

FIG. 2 shows the internal configuration of the sound field correction unit 2. The sound field correction unit 2 is supplied with a digital audio signal SOP to a terminal 21 from the audio signal source 1 during normal operation and from the PC board 6 during correction. The digital audio signal SOP input from the terminal 21 is
The digital audio signal received and input at 2 and taken in by the digital receiver 22 is supplied to the DSP 23. DSP
23 performs required acoustic processing, for example, frequency characteristic processing, using the D-RAM 24 for data memory. The processed audio signal is supplied to a D / A converter 25, converted into an analog audio signal SA, and output from a terminal 27 to a power amplifier 3 at a subsequent stage through a level adjustment by a volume 26.

The controller 28 includes the sound field correction unit 2
Is formed by a one-chip microcomputer to control the inside of the DSP 23, and controls the sound processing in the DSP 23. The flash memory 31 is used for storing microcodes and operation coefficients in the DSP 23. The controller 28 can communicate with an external device connected via a terminal 30 via a serial bus SB or the like via a bus interface 29. In this example, the personal computer 5 is connected to the personal computer 5.
When a calculation coefficient (parameter) or the like for acoustic processing is transmitted from the controller 28, the controller 28 can take in the data via the bus interface 29 and store it in the flash memory 31. Further, the actual sound processing in the DSP 23 can be executed based on the parameters stored in the flash memory 31.

FIG. 3 shows the internal configuration of the PC board 6. By connecting the PC board 6 as shown in FIG. 1 at the time of sound field correction, a digital audio signal SOP is supplied from the audio signal source 1 to the terminal 41 to the PC board 6. The digital audio signal SOP input from the terminal 41 is received and input by the digital receiver 42,
The digital audio signal captured in step 2 is supplied to the DSP 43. The DSP 43 is a D-RAM 4 for data memory.
4, the required acoustic processing, for example, the frequency characteristic processing can be performed. The DSP 43 has the same signal processing capability as the DSP 23 in the sound field correction unit 2. For example, the DSP 43 is a DSP chip having the same specifications as the DSP 23 and is mounted on the PC board 6. The audio signal processed by the DSP 43 is transmitted from the digital transmitter 45 to an external device connected to the terminal 46 as a digital audio signal SOP. In this example, the digital audio signal SOP is supplied to the sound field correction unit 2.

Personal computer 5 and PC board 6
(DSP43) is a high-speed bus system PB as described above.
, And the control regarding the sound processing in the DSP 43 is directly executed by the personal computer 5. That is, the personal computer 5 executes the setting change of the DSP 43 such as the calculation parameters for changing the sound processing characteristics.

A microphone input terminal 35 is provided on the PC board 6, and the microphone 7 is connected to the microphone input terminal 35. The audio signal collected by the microphone 7 is transmitted to the microphone amplifier 3
After amplification / level adjustment by the A / D converter 33, the A / D converter 33
Is converted into digital data. A / D converter 33
Is output to the high-speed bus system PB via the interface unit 34. Therefore, the personal computer 5 can take in the sound data collected by the microphone 7, that is, analyze the current sound field characteristics.

The sound field correcting operation performed in the configuration of the present embodiment shown in FIGS. 1 to 3 will be described with reference to FIG. FIG. 4 is a flowchart showing the processing of the personal computer 5 when executing the sound field correction.

As shown in FIG. 1, the PC board 6 is inserted and connected between the audio signal source 1 and the sound field correction unit 2, and the personal computer 5 and the sound field correction unit 2 are connected in a communicable state. When the correction operation is started, the personal computer 5 starts the processing in FIG. First, as step F101, a command is sent to the controller 28 of the sound field correction unit 2, and the sound processing in the DSP 23 is set to a through state. That is, the DSP 23 does not execute the sound processing, and the sound field correction unit 2 outputs the digital audio signal SOP to the power amplifier 3 only by directly converting the input digital audio signal SOP into the analog audio signal SA.

Next, after setting a variable n = 0 for loop control in step F102,
The process proceeds to a characteristic setting loop of F109. First, step F10
In step 2, the current sound field characteristics are analyzed. That is, analysis is performed on the audio data collected by the microphone 7, and the frequency characteristic is detected.

At the time of sound field characteristic correction, a target sound field characteristic is set before the execution, and the sound field correction operation is performed by changing the frequency characteristic analyzed in step F103 to the target sound field characteristic. This is an operation for matching the frequency characteristics selected / set as. Therefore, in step F104, the current sound field characteristic is compared with the target sound field characteristic,
Determine whether they match. If they do not match, the process proceeds to obtain the target characteristics. That is, the personal computer 5 first determines in step F105
The inverse characteristic of the analysis result of the current frequency characteristic is calculated, and then, in step F106, the inverse characteristic is multiplied by the target characteristic to calculate an operation coefficient. The calculation result is a processing parameter of the DSP 23 that executes the sound processing for obtaining the target sound field characteristic. However, in step F107, the personal computer 5 does not transmit these processing parameters to the DSP 23 side of the sound field correction unit 2, and the high-speed bus system PB
Through the DSP 43 of the PC board 6. Therefore, hereafter, the sound processing in the DSP 43 is executed by the transmitted parameters.

During the correction operation period, the sound field correction unit 2
Since the sound processing in step (1) is in a through state, the sound signal output from the sound signal source 1 is sent to the power amplifier 3 only after the sound processing in the PC board 6 is given, and is output from the speaker 4. .

The process of the personal computer 5 returns to step F103, and again analyzes the sound data collected by the microphone 7 to detect the frequency characteristic. That is, the sound field characteristics that are changed in accordance with the setting change in the DSP 43 immediately before that are analyzed.
Then, it is determined in step F104 whether or not the sound field characteristic matches the target sound field characteristic.

Until a match is obtained in step F104,
The loop processing of steps F103, F105, F107, and F107 is executed, and the processing characteristic setting of the DSP 43 is changed by the required number of times so that the desired sound field characteristic is obtained. Then, if a match is obtained in step F104, the variable n is incremented in step F108, and the flow advances to step F109 to determine whether or not the variable n is equal to or larger than the constant x. The constant x is a constant for improving the reliability of the sound field correction operation. When the result that the analyzed sound field characteristic matches the target characteristic is obtained x times, the sound field characteristic correction is completed. is there. Therefore, assuming that x = 5, the sound field measurement is repeated until the result that the target characteristic matches the current sound field characteristic is obtained five times in step F104. DS
It is determined that the processing characteristics of P43 are the optimum processing characteristics for realizing the target sound field characteristics.

When a negative result is obtained in step F104, the variable n may be reset to zero. In other words, this is a case where the correction is considered to be completed only when a positive result is obtained x times in succession in step F104.

If an affirmative result is obtained in step F109, the process proceeds to step F110, where the personal computer 5 performs the first operation of the sound field correction unit 2 at this stage.
The setting change process for SP23 will be performed. That is, the processing parameters and necessary microcodes executed by the DSP 43 at that time are transmitted to the controller 28 via the serial bus SB and stored in the flash memory 31. Then, the DSP 23 executes a process according to the process parameter set in the flash memory 31.

When the correction operation is completed, the PC board 6 is removed, and the audio signal from the audio signal source 1 is directly supplied to the sound field correction unit 2.
The SP 23 executes sound processing (equalizing) with the same processing parameters as the processing parameters executed by the DSP 43 when ending the correction operation. As described above, since the DSP 23 and the DSP 43 are the same DSP chip, the DSP 23 is executed when the PC board 6 is removed.
By the acoustic processing of SP23, a sound field characteristic that matches the target sound field characteristic is realized.

In this embodiment, a personal computer which has a much higher calculation capability than a general one-chip microcomputer and can perform calculations using data having a large word length or, for example, large-scale data using a built-in hard disk. Since the setting of the DSP is changed based on the parameter calculation according to 5, it is possible to perform a sound field correction that is quite strictly matched with the target characteristic.

In the correction operation of the present embodiment, the DSP setting change processing in step F107 is executed a required number of times (several times to several tens times) as occasion demands. With regard to such automatic sound field correction, more accurate correction can be performed by taking a large number of samples as sound field characteristics and removing one-off noises other than the original sound field characteristics. That is, the number of executions of the DSP setting change process increases as the correction operation is improved. Therefore, the DSP setting change time greatly affects the correction operation time. In this example, the communication for changing the setting is executed by the high-speed bus system PB of the personal computer 5 instead of the connection cable of the external device. That is, since the high-speed bus system PB is a communication system that does not occupy the CPU and does not require communication flow control, such as a DMA of a PC bus interface, the communication speed can be extremely high. For example, when it takes about three minutes for a personal computer to directly change the DSP of an external device as in the related art, in this example, the personal computer 5 changes the setting of the DSP 43 as an internal unit. Can be shortened to around seconds. Therefore, the operation time is significantly reduced in the entire sound field correction operation. And D
While the sound output is muted during the period of changing the setting of SP43, in the case of this example, the period during which the user feels that the sound is interrupted during the execution of the correction is the period of about 10 seconds during which the process of step F107 is performed. Becomes For this reason, it becomes easy to perceive the change of the sound field before and after the DSP setting change.

Although the embodiments of the present invention have been described above, it goes without saying that various other modifications are possible for the configuration example of the sound field correction device. For example, another computer such as a workstation may be used instead of a personal computer. The transmission form of the audio signal need not be an optical digital system.

[0039]

As described above, according to the present invention, an optimal and highly accurate sound field can be obtained by using an operation control means having a high operation capability capable of executing parameter calculation for sound field correction such as a personal computer. There is an effect that correction can be performed. In addition, there is an effect that the time required for the correction processing can be significantly reduced. That is, during the correction operation, the setting change is not performed for the sound processing unit that should be actually changed, and the correction sound processing unit that can perform the same sound processing as the sound processing unit is used. In order to obtain sound field characteristics, the sound processing means for correction is connected directly to the internal high-speed bus unit of the computer device, for example, in the form of an expansion unit. This is because the communication time for changing the setting of the processing characteristics is significantly reduced. In addition, since the time required to change the setting of the acoustic characteristics is shortened, the time that the user feels that the sound is cut off is short, and the change in the sound field characteristic before and after the setting change can be perceived well audibly. The advantage is also obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of a sound field correction system according to an embodiment of the present invention.

FIG. 2 is a block diagram of a sound field correction unit according to the embodiment.

FIG. 3 is a block diagram of a PC board according to the embodiment;

FIG. 4 is a flowchart of a sound field correction process according to the embodiment.

FIG. 5 is a block diagram of a conventional sound field correction system.

[Explanation of symbols]

1 audio signal source, 2 sound field correction unit, 3 power amplifier, 4 speakers, 5, personal computer, 6 PC board, 7 microphone, 23, 43
DSP, 28 controller, 29 bus interface, 31 flash memory, PB high-speed bus system (PC bus interface)

Claims (2)

[Claims] 1. An audio signal source, audio processing means capable of performing predetermined acoustic characteristic processing on an audio signal from the audio signal source, and outputting the audio signal processed by the audio processing means as audio. A sound field correction system that can correct the sound field characteristics of a sound field forming system having a sound output unit that performs the sound processing at least during the correction operation. An arithmetic control unit capable of performing setting control of sound processing characteristics in the processing unit; and a high-speed bus system capable of communicating with the arithmetic control unit and performing the same sound processing as the sound processing unit. And at least at the time of a correction operation, inputting an audio signal from the audio signal source, performing acoustic processing, and outputting the audio signal as audio from the audio output unit. And a measuring means for measuring a sound field characteristic of the sound output from the sound output unit, wherein the arithmetic control means performs the correcting sound processing during a correcting operation. Calculating a sound processing parameter for realizing a target sound field characteristic from the sound field characteristics measured by the measuring means for the sound output from the sound output unit through the sound processing by the means; While causing the correction sound processing means to execute the sound processing based on the processing parameter, and when the sound field characteristic measured by the measurement means matches the target sound field characteristic, the sound processing means is used by the correction sound processing means at that time. A sound field correction device for setting a sound processing parameter to the sound processing means. 2. The arithmetic control means is a computer device connected to the sound field forming system at the time of sound field correction, and the correction sound means is directly connected to an internal high-speed bus system of the computer device. The sound field correction device according to claim 1, wherein the sound field correction device is formed as an extended unit.