JP2006094149A - Amplifier unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an amplifier unit having an attached microphone including an automatic adjustment function, enabling the microphone to be suitable for collecting a particular sound such as karaoke or a speech in addition to the use of the microphone with the automatic adjustment function. <P>SOLUTION: The amplifier unit includes a selection for selecting a function for adjusting a frequency characteristic of audio signals regenerated by a plurality of speakers connected to the amplifier unit; a sound collector for collecting the signals regenerated by the speakers; and, when the frequency characteristic adjustment function is selected in the selection section, a control unit for controlling to switch a directivity characteristic of the sound collector to non-directivity, and to set an audible frequency band to be the signal frequency band passed through a filter. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an amplifying apparatus capable of amplifying and outputting an audio signal and adjusting the acoustic characteristics of the audio signal reproduced from a speaker.

  As a recording medium on which a multi-channel audio signal is recorded, there is a DVD (Digital Versatile Disc). The multi-channel audio signal read from the DVD by the playback device is input to an amplification device (for example, an AV (Audio Visual) amplifier). This amplifying device converts an input multi-channel audio signal into a plurality of channels of audio signals, amplifies the converted audio signals, and outputs them to a plurality of speakers. The multi-channel audio signal output from the amplifying device can be reproduced as sound waves from a plurality of speakers, thereby reproducing a sound field having a surround effect.

  In order to reproduce a sound field having a surround effect, in the amplifying apparatus, various types of acoustic characteristics such as the phase of the audio signal between the channels, the sound pressure level of the audio signal reproduced from each speaker, and the frequency characteristics of each speaker It is necessary to set the parameter value to an appropriate value. Although the user manually sets the values of these parameters, there is an amplifying apparatus having an automatic adjustment function that can automatically set the values of these parameters.

  An amplification device equipped with an automatic adjustment function of acoustic characteristics reproduces test signals from each speaker, collects the test signals reproduced from each speaker from a microphone installed at the listening position and connected to the amplification device, and collects the sound. The frequency characteristics and sound pressure level of the test signal, the delay time of the test signal for each channel, etc. are measured. The amplifying apparatus adjusts the measured frequency characteristics, sound pressure level, delay time, and the like so as to match preset frequency characteristics, sound pressure level, delay time, and the like (for example, Patent Document 1 and Patent Document 2). reference).

JP 2002-354599 A JP 2000-354300 A

  The microphone used for the automatic adjustment function is attached to the amplification device. This microphone has an omnidirectional directional characteristic that is sensitive to a 360 degree direction in order to collect test signals that are installed at the listening position and reproduced from speakers installed around the listening position. Yes. The automatic adjustment function is performed when initializing the amplification device, such as when a new speaker is connected, or when the location where the amplification device and the speaker are installed is changed. For this reason, conventionally, the microphone used in the automatic adjustment function has not been used for any purpose other than that used for automatic adjustment.

  Therefore, when a microphone with a non-directional directivity is used in an application other than automatic adjustment of acoustic characteristics, for example, when used as a microphone that collects a specific sound such as karaoke or speech, the non-directional microphone is In addition to voice, noise around the microphone is also collected. For this reason, the sound collected by the microphone and reproduced from the speaker via the amplifier includes a problem that the sound quality deteriorates because it includes noise. In addition, since the microphone is an omnidirectional microphone, there is a problem that howling is likely to occur because the microphone collects the sound reproduced from the speaker.

  The present invention has been made to solve the above-described problem, and in the microphone attached to the amplifying apparatus having the automatic adjustment function of the acoustic characteristics, in addition to using this microphone for automatic adjustment, for example, An object of the present invention is to provide an amplifying apparatus that can be used as a microphone suitable for collecting voice such as karaoke and speech.

  In order to solve the above-described problem, an invention according to claim 1 of the present application includes an output unit that amplifies and outputs an audio signal, and an amplification device that has a function of adjusting an acoustic characteristic of the audio signal output from the output unit. And selecting a function for adjusting the acoustic characteristics of audio signals reproduced as sound waves from a plurality of speakers connected to the amplifier, and measuring the acoustic characteristics of audio signals reproduced as sound waves from the speakers A test signal generator for generating a test signal, a sound collector for collecting a test signal reproduced as a sound wave from the speaker, and a sound wave from the speaker based on the test signal collected by the sound collector A signal processing unit that adjusts the acoustic characteristics of the audio signal to be played back, and a function that adjusts the acoustic characteristics by the selection unit is selected , Characterized in that it comprises a control unit for controlling to switch the directivity of the sound collecting portion to omnidirectional.

  The invention according to claim 2 of the present application is the amplification device according to claim 1, further passing a signal in a predetermined frequency band from the signal collected by the sound collecting unit to the signal processing unit. An output filter unit, and the signal processing unit has a function of adjusting a frequency characteristic, and the control unit allows the filter unit to pass when the function of adjusting the frequency characteristic is selected by the selection unit. Control is performed to make the frequency band of the signal an audible frequency band.

  According to a third aspect of the present invention, in the amplification device according to the second aspect, when the function for adjusting the acoustic characteristic is not selected by the selection unit, the control unit is configured to direct the directivity of the sound collection unit. Is controlled to make the frequency band of the signal passed by the filter unit narrower than the audible frequency band.

  According to the amplifying apparatus of the present invention, in the microphone attached to the amplifying apparatus having an automatic adjustment function, the microphone is suitable for collecting sound such as karaoke and speech, for example, in addition to using the microphone in the automatic adjustment function. An amplifying device that can be used as a microphone can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an amplifying apparatus according to an embodiment of the present invention. In FIG. 1, 1 is an audio signal input unit, 2 is a signal processing unit, 3 is an audio signal output unit, 4 is a test signal generation unit, 5 is a collected sound signal input unit, 6 is a filter unit, 7 is an operation unit, 8 Is a control unit, 9 is a control signal output unit, and 10 is a microphone. The amplifying apparatus according to the present embodiment relates to various acoustic characteristics such as the phase of the audio signal between the channels, the sound pressure level of the audio signal reproduced from each speaker, the delay time of the audio signal of each channel, and the frequency characteristics of each speaker. It has an automatic adjustment function that automatically sets parameter values to appropriate values.

  An audio signal input unit 1 shown in FIG. 1 inputs a multi-channel digital audio signal output from a playback device such as a DVD player. The signal processing unit 2 decodes the digital audio signal input from the audio signal input unit 1, performs signal processing such as surround and sound field effect addition, and separates the digital audio signal for each channel. When the input digital audio signal is a 5.1 channel digital audio signal, the signal processing unit 2 performs FL (Front Left) channel, FR (Front Right) channel, C (Center) channel, SL (Surround Left). It is separated into digital audio signals of channel, SR (Surround Right) channel and SW (Sub Woofer) channel.

  When the signal processing unit 2 performs automatic adjustment of acoustic characteristics, when the collected sound signal (test signal) collected by the microphone 10 is input from the filter unit 6, the phase of the audio signal between the channels, The acoustic characteristics such as the sound pressure level of the audio signal reproduced as a sound wave from each speaker, the delay time of the audio signal of each channel, and the frequency characteristics of each speaker are measured. The signal processing unit 2 adjusts the values of various parameters related to acoustic characteristics to appropriate values according to the measurement results. The values of various parameters relating to the adjusted acoustic characteristics are stored in a memory (not shown) included in the signal processing unit 2.

  Further, when the sound processing signal collected by the microphone 10 is input from the filter unit 6 when the acoustic characteristic is not automatically adjusted, the signal processing unit 2 receives the signal from the filter unit 6. Processing is performed and input to the output unit 3.

  The audio signal output unit 3 converts the digital audio signal of each channel output from the signal processing unit 2 into an analog audio signal, amplifies it, and outputs it to a speaker connected to the audio signal output unit 3. FIG. 2 is a diagram showing a general arrangement of 5.1 channel speakers. As shown in FIG. 2, the FL channel speaker 11 on the front left of the listening position, the FR channel speaker 12 on the front right, the C channel speaker 13 on the front center, the SL channel speaker 14 on the rear left, and the SR channel speaker 15 on the rear right. Has been placed. An SW channel speaker 16 is disposed at an arbitrary position.

  The test signal generator 4 generates a test signal used for measuring values of various parameters related to the acoustic characteristics during automatic adjustment of the acoustic characteristics. The test signal generated by the test signal generation unit 4 is reproduced from the speakers 11 to 16 via the signal processing unit 2 and the audio signal output unit 3. This test signal is white noise, pink noise, or the like.

  The sound collection signal input unit 5 is connected to the microphone 10 and inputs a sound collection signal collected by the microphone 10. The sound collection signal input unit 4 converts the input sound collection signal from an analog signal to a digital signal, amplifies it, and inputs it to the filter unit 6.

  The filter unit 6 is a band-pass filter having a characteristic of allowing only a signal in a predetermined frequency band to pass through the collected sound signal input from the collected sound signal input unit 5. The filter unit 6 determines a frequency band through which the collected sound signal passes under the control of the control unit 8. The collected sound signal that has passed through the filter unit 6 is input to the signal processing unit 2.

  The operation unit 7 includes a selection button for selecting the automatic adjustment function, a start button for starting the operation of the automatic adjustment function, and an operation button for inputting or changing each parameter of the acoustic characteristics. The control unit 8 controls the entire amplifying apparatus of this embodiment.

  When starting the operation of the automatic adjustment function, the control unit 8 inputs a control signal for making the directivity of the microphone 10 non-directional to the control signal output unit 9. The control signal output unit 9 is connected to the microphone 10 and outputs the control signal input from the control unit 8 to the microphone 10. Further, the control unit 8 controls the filter unit 6 to set the pass frequency band to an audible frequency band (20 Hz to 20 kHz).

  When the automatic adjustment function is selected by the selection button of the operation unit 7 and the start button is pressed, the control unit 8 controls the test signal generation unit 4 to generate a test signal. The control unit 8 performs control such that the test signal generated by the test signal generation unit 4 is output from the audio signal output unit 3 to the speakers 11 to 16 in a predetermined order via the signal processing unit 2. .

  The microphone 10 is a sound collection unit that can switch directivity between non-directional and unidirectional. FIG. 3 is a diagram showing the structure of the microphone 10 that can switch the directivity according to an embodiment of the present invention. As shown in FIG. 3, the microphone element 21 provided inside the microphone 10 includes a diaphragm 22 on the front surface of the microphone 10 and a hole 23 on the rear side of the diaphragm 22. The microphone 10 receives sound pressure from the diaphragm 22 and converts sound into an electric signal by a power generation mechanism (not shown). The microphone 10 opens and closes a hole 23 by an opening / closing mechanism (not shown) when a control signal for making the directional characteristics unidirectional is input, and opens and closes (not shown) when a control signal for making the directional characteristics omnidirectional is input. By closing the hole 23 by the mechanism, the directivity can be switched. This opening / closing mechanism can open and close the hole 23 by electric power input together with the control signal.

  The microphone 10 functions as an omnidirectional microphone that collects ambient sounds when the hole 23 is closed by a control signal from the control unit 8. Further, when the hole 23 is opened by the control signal of the control unit 8, there is a difference between the sound pressure level and the phase of the sound transmitted from the front of the microphone 10 to the diaphragm 22 and the sound transmitted from the hole 23 to the diaphragm 22, and vibration is generated. The sound transmitted from the rear in the plate 22 is canceled out. For this reason, the microphone 10 functions as a unidirectional microphone that collects only sound from the front. Further, as another embodiment of the microphone 10 that can switch the directivity, the microphone 10 includes a non-directional microphone element and a unidirectional microphone element, and switches to a microphone element according to a control signal of the control unit 8. It is good also as a structure. When the acoustic characteristics are automatically adjusted, the microphone 10 is installed at the same height as the position of the user's ear at a position (listening position) where the user's audio signal is listened as shown in FIG.

  FIG. 4 is a flowchart for explaining the operation of the automatic adjustment function of the amplifying apparatus according to the embodiment of the present invention.

  Step 1 shown in FIG. 4 is a step in which the user selects the automatic adjustment function by the operation unit 8. The user selects the automatic adjustment function with the selection button of the operation unit 7 and presses the start button.

  Step 2 is a step in which the control unit 8 outputs a control signal that makes the directivity of the microphone 10 non-directional. The control unit 8 outputs a control signal for making the directivity of the microphone 10 non-directional to the microphone 10 via the control signal output unit 9.

  Step 3 is a step in which the microphone 10 switches the directivity characteristic to omnidirectional. When a non-directional control signal is input, the microphone 10 closes the hole 23 shown in FIG. 3 in order to make the directivity characteristic nondirectional.

  Step 4 is a step in which the control unit 8 controls the pass frequency band of the filter unit 6 to be an audible frequency band (20 Hz to 20 kHz). The control unit 8 controls the pass frequency band of the filter unit 6 to be an audible frequency band in order to input a test signal in the audible frequency band from the test signal collected by the microphone 10 to the signal processing unit 2. Therefore, the signal processing unit 2 can measure the acoustic characteristics of the test signal in the audible frequency band.

  Step 5 is a step in which the control unit 8 controls the test signal generation unit 4 to generate a test signal. The control unit 8 performs control such that the test signal generated by the test signal generation unit 4 is output from the audio signal output unit 3 to the speakers 11 to 16 in a predetermined order via the signal processing unit 2. .

  Step 6 is a step in which the signal processing unit 2 measures the acoustic characteristics under the control of the control unit 8 and adjusts the values of various parameters relating to the acoustic characteristics to appropriate values according to the measurement results. When the test signal collected by the microphone 10 is input from the filter unit 6, the signal processing unit 2 receives the phase of the audio signal between the channels, the sound pressure level of the audio signal reproduced from each speaker, Measure acoustic characteristics such as audio signal delay time and frequency characteristics of each speaker. The signal processing unit 2 adjusts the values of various parameters related to acoustic characteristics to appropriate values according to the measurement results.

  Step 7 is a step in which the control unit 8 determines whether or not the adjustment of the acoustic characteristics has been completed. When the control unit 8 determines that the adjustment of the acoustic characteristics is completed, the control unit 8 performs control to end the operation of the automatic adjustment function. When the adjustment of the acoustic characteristics is completed, the process proceeds to Step 8.

  Step 8 is a step in which the control unit 8 outputs a control signal that makes the directivity of the microphone 10 unidirectional. The control unit 8 outputs a control signal that makes the directivity of the microphone 10 unidirectional to the microphone 10 via the control signal output unit 9. When a control signal for unidirectionality is input, the microphone 10 opens the hole 23 shown in FIG. 3 in order to make the directional characteristic unidirectional.

  Step 9 is a step in which the control unit 8 performs control so that the pass frequency band of the filter unit 6 is narrower than the audible frequency band (for example, 50 Hz to 12.5 kHz). The control unit 8 passes the frequency band of the filter unit 6 so that a signal in a human voice band (hereinafter referred to as a voice frequency band) is input to the signal processing unit 2 from the collected sound signal collected by the microphone 10. Is set to a frequency band (audio frequency band) narrower than the audible frequency band.

  When the operation of the automatic adjustment function is started, the amplification device according to the present embodiment makes the directivity characteristic of the microphone 10 non-directional. The omnidirectional microphone 10 can collect test signals reproduced from the speakers 11 to 16 installed around the microphone 10 as shown in FIG. On the other hand, when the values of various parameters relating to acoustic characteristics are measured using a microphone having no omnidirectionality (for example, a unidirectional microphone), the speakers 11 to 16 installed around the microphone 10 are used. I can't collect all the test signals to be played. Therefore, in the amplifying apparatus of this embodiment, when the automatic adjustment function is started, the microphone 10 collects all test signals reproduced from the speakers 11 to 16 by making the directivity characteristic of the microphone 10 non-directional. It is possible to accurately measure various parameter values relating to acoustic characteristics.

  Further, the amplifying apparatus of the present embodiment makes the directivity characteristic of the microphone 10 non-directional and makes the pass frequency band of the filter unit 6 an audible frequency band (20 Hz to 20 kHz). Therefore, since the signal processing unit 2 receives the test signal in the audible frequency band from the test signal collected by the microphone 10, it can measure the acoustic characteristics in the audible frequency band.

  When the operation of the automatic adjustment function ends, the amplification device of the present embodiment makes the directivity of the microphone 10 unidirectional. Since the microphone 10 having unidirectionality collects only sound from the front, it can be used as a microphone that collects a specific sound such as karaoke or speech. For this reason, it is possible to prevent howling that occurs when the microphone 10 collects the sound signal collected by the microphone 10 and reproduced from the speaker via the amplifier.

  In the amplifying apparatus of the present embodiment, the directivity characteristic of the microphone 10 is unidirectional, and the pass frequency band of the filter unit 6 is an audio frequency band (for example, 50 Hz to 12.5 kHz). For this reason, even if noise is collected together with sound by the microphone 10, only the sound signal can be input to the signal processing unit 2. Therefore, the sound collected by the microphone 10 and reproduced from the speaker via the amplifying device can be obtained. Can be clear.

  The amplifying apparatus of the present embodiment described above performs control to switch the directivity characteristics of the microphone 10 depending on whether the automatic adjustment function is performed or not, and further, the sound collecting signal input to the signal processing unit 2 is controlled. Since the control for changing the frequency band is performed, the microphone 10 can be used as a microphone suitable for collecting a specific audio signal such as karaoke or speech in addition to using the microphone 10 with an automatic adjustment function.

The block diagram which shows the structure of the amplifier which is an Example of this invention. The figure which shows arrangement | positioning of the general speaker of 5.1 channels. 1 is a diagram illustrating a structure of a microphone 10. FIG. The flowchart explaining the operation | movement which performs the automatic adjustment function of the amplifier which is an Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Audio signal input part, 2 ... Signal processing part, 3 ... Audio signal output part, 4 ... Test signal generation part, 5 ... Sound collection signal input part, 6 ... Filter part, 7 ... Operation part, 8 ... Control part, DESCRIPTION OF SYMBOLS 9 ... Control signal output part, 10 ... Microphone, 11 ... FL channel speaker, 12 ... FR channel speaker, 13 ... C channel speaker, 14 ... SL channel speaker, 15 ... SR channel speaker, 16 ... SW channel speaker, 21 ... Microphone Element, 22 ... diaphragm, 23 ... hole

Claims (3)

In an amplifying apparatus having a function of adjusting an acoustic characteristic of an audio signal output from the output unit and the output unit that amplifies and outputs an audio signal;
A selection unit that selects a function of adjusting the acoustic characteristics of an audio signal reproduced as sound waves from a plurality of speakers connected to the amplification device;
A test signal generator for generating a test signal for measuring acoustic characteristics of an audio signal reproduced as a sound wave from the speaker;
A sound collection unit for collecting a test signal reproduced as a sound wave from the speaker;
A signal processing unit that adjusts an acoustic characteristic of an audio signal reproduced as a sound wave from the speaker based on the test signal collected by the sound collecting unit;
An amplifying apparatus comprising: a control unit that performs control to switch a directivity characteristic of the sound collection unit to non-directional when a function of adjusting an acoustic characteristic is selected by the selection unit. The amplification device according to claim 1,
And a filter unit that passes a signal in a predetermined frequency band from the signal collected by the sound collecting unit and outputs the signal to the signal processing unit,
The signal processing unit has a function of adjusting frequency characteristics,
When the function for adjusting frequency characteristics is selected by the selection unit, the control unit controls the frequency band of a signal passed by the filter unit to be an audible frequency band. The amplification device according to claim 2, wherein
When the function for adjusting the acoustic characteristics is not selected by the selection unit,
The control unit performs control to make the directivity characteristic of the sound collecting unit unidirectional and control to make a frequency band of a signal passed by the filter unit narrower than an audible frequency band. apparatus.

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