JP2012095011A - Acoustic system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a user to listen to natural reproduced sound in an acoustic system even when a listening position of the user is shifted from a specific (ideal) listening position.SOLUTION: Sound from a speaker is outputted while being subjected to a frequency sweep (S1). On the basis of levels of individual frequency bands of an input signal inputted from a microphone disposed at a position in front of and in the vicinity of the speaker, correction values of the individual frequency bands are calculated, and a correction table storing these correction values is preserved in a memory (S2 to S5). By having the correction table, natural reproduced sound can be obtained by correcting so that the levels of the individual frequency bands of output sound from the speaker at the position in front of and in the vicinity of the speaker become flat on the basis of the correction values of the individual frequency bands stored in the table.

Description

  The present invention relates to an acoustic system in which an amplifier and a speaker are combined.

  Conventionally, as an acoustic system in which an amplifier and a speaker are set, a so-called HTiB (Home Theater in Box), a sound bar in which the amplifier and the speaker are housed in the same housing, a rack theater, and the like are known. HTiB is a packaged product of audio equipment such as a BD (Blu-ray Disc) / DVD (Digital Versatile Disc) player, an AV amplifier, and a plurality of speakers including a subwoofer, and is an audio system for a home theater. The sound bar is an acoustic system in which an AV amplifier and several speakers including a subwoofer are housed in the same casing. The rack theater is a space-saving acoustic system in which speakers and an amplifier are incorporated in a rack.

  In a conventional acoustic system, in order to enable a user to listen to a comfortable sound when listening to a sound at a specific listening position, according to the distance between the specific listening position and each speaker. The delay amount of the audio signal input to each speaker is adjusted, and the amplification factor (gain) of the audio signal input to each speaker is adjusted (see, for example, Patent Document 1). For this reason, in the conventional acoustic system, the level (frequency characteristic of the output sound from each speaker) of the output sound from each speaker is corrected to be flat to obtain a natural reproduction sound. Even in this case, level correction is performed for each frequency band of the audio signal input to each speaker so that the frequency characteristics of the audio at the specific listening position are flat. Therefore, if the user's listening position is slightly deviated from the specific (ideal) listening position, there is a problem that the user cannot hear a natural reproduced sound due to the influence of reflected sound.

  By the way, in the field of this type of acoustic system, a sub-speaker having a main speaker unit and a sub-speaker unit each having a different sound axis direction and mainly responsible for indirect sound when the user is at a specific listening position. An audio signal that can be adjusted independently of the main speaker unit is known (for example, see Patent Document 2). However, the invention of the cited document 2 cannot solve the above problem.

JP 2009-206818 A JP 2004-349793 A

  The present invention solves the above-described problems, and provides an acoustic system that allows a user to listen to natural reproduced sound even when the user's listening position deviates from a specific (ideal) listening position. For the purpose.

  In order to solve the above-mentioned problem, the invention of claim 1 includes a correction table storage means for storing a correction table storing correction values for each frequency band of an input audio signal, and each of the correction tables stored in the correction table. An audio signal correction unit that corrects the level of the input audio signal based on a correction value for each frequency band, an audio signal amplification unit that amplifies the audio signal level-corrected by the audio signal correction unit, and the audio signal In a sound system comprising: a speaker that converts the sound signal amplified by the amplification means into sound and outputs the sound; and the correction table storage means, the sound signal correction means, the sound signal amplification means, and the speaker are set. The correction value for each frequency band stored in the correction table is the sound output from the speaker at a position in front of and near the speaker. The level of each frequency band, but a correction value for correcting flat.

  According to a second aspect of the present invention, there is provided the acoustic system according to the first aspect, wherein frequency sweeping means for outputting the audio signal of the same level to the audio signal amplification means while sweeping the frequency, and a position in front of and in the vicinity of the speaker. And an input means for inputting an input signal from a microphone arranged in the microphone, and a correction value calculating means for calculating a correction value for each frequency band of the audio signal stored in the correction table, the correction value The calculation means outputs the sound signal of the same level from the speaker while performing the frequency sweep by outputting the sound signal of the same level to the sound signal amplification means while performing the frequency sweep using the frequency sweep means. An input signal corresponding to voice is input from the microphone by the input means, and from the microphone. Based on the level of each frequency band of the power input signals, and calculates a correction value for each of said frequency bands.

  According to a third aspect of the present invention, in the acoustic system according to the first or second aspect, the number of the speakers is two or more, and the correction table storage means stores a correction table corresponding to each speaker. It is.

  According to the first aspect of the present invention, based on the correction value for each frequency band stored in the correction table, the level (speaker for each frequency band) of the output sound from the speaker at a position in front of and near the speaker. Since the frequency characteristics of the sound output from the speaker can be corrected to flat, the level for each frequency band of the sound immediately after being output from the speaker (the frequency characteristic of the sound immediately after being output from the speaker) is flattened. The natural reproduction sound can be obtained by correcting. As a result, even when the user's listening position deviates from a specific (ideal) listening position, the user can listen to natural reproduced sound, so that the user can be prevented from getting tired.

  According to the invention of claim 2, the sound is output from the speaker while being swept in frequency, and based on the level for each frequency band of the input signal input from the microphone disposed in front of and in the vicinity of the speaker. Thus, by calculating the correction value for each frequency band, the effects described above can be obtained accurately. In addition, since the correction value for each frequency band stored in the correction table is calculated using the sound actually output from the speaker connected to this acoustic system, it is actually used for this acoustic system. Even if there are individual differences in the speakers and sound signal amplification means (for example, amplifiers) that are used, the level of each frequency band of the sound immediately after being output from the speakers is corrected to flat to obtain a natural reproduced sound Can do. Furthermore, since the correction value for each frequency band stored in the correction table can be obtained using the acoustic system itself, no special measuring device is required to obtain the correction value stored in the correction table. Become.

  According to a third aspect of the present invention, since the correction table corresponding to each speaker is stored, in the acoustic system using a plurality of speakers such as the surround system and the virtual surround system, the above-described effects can be obtained. Obtainable.

The block block diagram of HTiB which is an acoustic system which concerns on one Embodiment of this invention. The flowchart of the correction table creation process in the same HTiB. The flowchart of the reproduction | regeneration processing at the time of the flat mode in the same HTiB.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This embodiment demonstrates the example in case the acoustic system of this invention is what is called a HTiB (Home Theater in Box). FIG. 1 shows an HTiB 1 according to the present embodiment and a liquid crystal television receiver (hereinafter abbreviated as a liquid crystal television) 30 connected to the HTiB 1. The HTiB 1 is a BD (Blu-ray Disc) / DVD (Digital Versatile Disc) player 2, a radio (for broadcast reception) tuner 3, an AV amplifier 4, and a speaker 5 (a general term for six speakers 5 a to 5 f). An input terminal 6 (input means) for inputting an input signal from the microphone 26; an A / D converter 7 for converting an analog input signal input from the microphone 26 into a digital input signal; The remote control signal receiving device 8 for receiving a remote control signal from the remote control 21 is configured, and these components are a set. Of these components, components other than the speaker 5 are housed in the housing 1a. The remote controller 21 is used for the operation of the HTiB 1 by the user.

  The AV amplifier 4 serves as a video / audio signal selector. In the example shown in FIG. 1, the AV amplifier 4 selects a 5.1 channel input signal from either the BD / DVD player 2 or the radio tuner 3 and converts the input audio signal into six speakers. Distribute, amplify and send to 5a-5f. The six speakers 5a to 5f are a subwoofer that is a center speaker, a front R (Right) speaker, a front L (Left) speaker, a rear R (Right) speaker, a rear L (Left) speaker, and a speaker dedicated to low-frequency reproduction. Consists of That is, these speakers 5a to 5f constitute a so-called 5.1 channel surround speaker system.

  The AV amplifier 4 includes a CPU 10 (correction value calculation means) that controls the entire AV amplifier 4 and a DSP (Digital Signal Processor) 11 (a digital field processor that performs sound field processing or frequency characteristic correction processing on the input audio signal. An audio signal correcting means), an amplifier 12 (audio signal amplifying means) for amplifying the audio signal output from the DSP 11, a memory 14 (correction table storage means), and a display unit 13 used for displaying various messages. Have. The CPU 10 and the DSP 11 correspond to the frequency sweep means in the claims. The memory 14 (correction table storage means), the DSP 11 (audio signal correction means), the amplifier 12 (audio signal amplification means), and the speakers 5a to 5f are a set. When the video / audio signal from the BD / DVD player 2 is selected as the input signal, the AV amplifier 4 outputs the video signal from the BD / DVD player 2 to the liquid crystal television 30 via the DSP 11.

  The AV amplifier 4 has various modes. For example, in the flat mode, the DSP 11 performs a process of correcting the level of the output sound from each speaker 5 at each position in front of and near each speaker 5 to be flat. The memory 14 stores a correction table 14a used for this correction process. The correction table 14a is a table that stores correction values for each frequency band of the input audio signal. These correction values are correction values for flatly correcting the level for each frequency band of the output sound in front and in the vicinity of each of the speakers 5a to 5f. For example, the correction value for the speaker 5a is a correction value for flatly correcting the level for each frequency band of the output sound from the speaker 5a at a position in front of and near the speaker 5a. The correction table 14a stores all correction values for correcting the level of each frequency band of the output sound from the speakers 5a to 5f to flat. In addition to the flat mode, the AV amplifier 4 has a classic mode in which correction processing suitable for classical music is performed and a jazz mode in which correction processing suitable for jazz is performed.

  The memory 14 also includes a correction table creation program 14b that is a program for creating the correction table 14a and a reproduction processing program 14c that is a program for performing reproduction processing corresponding to various modes including the flat mode. Etc., various programs and data are stored.

  Next, the creation process of the correction table 14a performed by the correction table creation program 14b will be described with reference to the flowchart of FIG. The process for creating the correction table 14a is performed at the time of adjustment of the HTiB 1 before factory shipment. The CPU 10 of the AV amplifier 4 outputs an audio signal of the same level to the amplifier 12 while frequency-sweeping the audio signal input to the DSP 11 from either the BD / DVD player 2 or the radio tuner 3 by the DSP 11. Audio is reproduced and output from any of 5a to 5f while frequency sweeping (S1). The input terminal 6 and the A / D converter are connected to the input signal 6 corresponding to the output sound from the microphone 26 disposed in the immediate vicinity of the speaker 5 (in front of and near the speaker 5) that actually output the sound. 7 to input. That is, the reproduction sound closest to the speaker 5 (in front and in the vicinity) is input to the microphone 26 (S2). Then, the CPU 10 temporarily stores the level for each frequency of the reproduced sound input from the speaker 5 (that is, the level for each frequency band of the input signal input from the microphone 26) input to the microphone 26 in the memory 14. (S3).

  The processes of S1 to S3 are performed in order for the speakers 5a to 5f. That is, the CPU 10 reproduces and outputs sound while sequentially sweeping the frequency from the speakers 5a to 5f, and inputs each of the input signals input to the microphone 26 disposed at a position closest to the speaker 5 that actually outputs the sound. The process of temporarily storing the level for each frequency band in the memory 14 is sequentially performed for all the speakers 5a to 5f. The number of frequency band divisions when frequency sweeping is performed in S1 is, for example, 128 or 256, and the range of the divided frequency bands is, for example, an audio band of 20 Hz to 20 kHz divided into 256 (or 128 divisions). Frequency band.

  The CPU 10 and the DSP 11 have an equalizer function that is a function for correcting the level (frequency characteristic) of each frequency band of the input signal. The CPU 10 corrects the peak and dip level (frequency characteristic (curve)) of each frequency of the reproduced sound stored in the memory 14 in S3 by using the equalizer function in conjunction with the DSP 11. As a result, the level (frequency characteristic) for each frequency of the reproduced sound primarily stored in the memory 14 in S3 is flattened (S4). Then, the CPU 10 creates a correction table 14a, which is a correction value table for each frequency band of the frequency characteristics corresponding to the speakers 5a to 5f, and stores it in the memory 14 (S5). As the correction value stored in the correction table 14a, the difference between the flat value in the frequency characteristic (curve) and the peak or dip value is used. Specifically, the correction value for the peak portion is a negative value obtained by subtracting the peak value from the flat value, and the correction value for the dip portion is a positive value obtained by subtracting the dip value from the flat value. Become. That is, the CPU 10 determines the frequency characteristics of all the speakers 5a to 5f based on the level (frequency characteristic) of each output frequency band of the output sound from all the speakers 5a to 5f temporarily stored in the memory 14. ) Calculate a correction value for each frequency band, and store the calculated correction value in the correction table 14 a of the memory 14.

  Next, playback processing (playback processing in flat mode) executed by the playback processing program 14c in the flat mode will be described with reference to FIG. When the user gives an instruction to execute the playback process in the flat mode using the remote controller 21, the CPU 10 of the AV amplifier 4 reads the contents of the correction table 14a and transfers them to the DSP 11 (S11). The DSP 11 selects the audio signal of each channel input from the BD / DVD player 2 or the radio tuner 3 based on the correction value for each frequency band (for each speaker 5a to 5f) stored in the correction table 14a. The level is corrected (S12). Then, by sending the corrected audio signal of each channel to the amplifier 12, the corrected audio signal of each channel is amplified by the amplifier 12, and the sound based on the amplified audio signal of each channel is sent to each speaker 5a. To 5f (S13). The flat mode reproduction process is a normal process performed after product shipment, unlike the correction table creation process shown in FIG.

  As described above, according to the HTiB1 of the present embodiment, each of the speakers 5a to 5f at the position nearest (forward and in the vicinity) based on the correction value for each frequency band stored in the correction table 14a. Since the level for each frequency band of the output sound from the speakers 5a to 5f (frequency characteristics of the output sound from the speakers 5a to 5f) can be corrected flat, immediately after being output from the speakers 5a to 5f The level (frequency characteristics of the sound immediately after being output from the speakers 5a to 5f) for each frequency band of the sound is corrected to be flat, and natural reproduced sound can be obtained. As a result, even when the user's listening position deviates from a specific (ideal) listening position, the user can listen to natural reproduced sound, so that the user can be prevented from getting tired.

  In addition, according to the HTiB1 of the present embodiment, sound is output from each speaker 5a to 5f while being swept in frequency, and is input from the microphone 26 disposed in the immediate vicinity (front and vicinity) of each speaker 5a to 5f. By calculating the correction value for each frequency band based on the level of the input signal for each frequency band, the effects described above can be obtained accurately. Further, since the correction value for each frequency band stored in the correction table 14a is calculated using the sound output from the speakers 5a to 5f actually connected to the HTiB1, the HTiB1 Even when there are individual differences between the speakers 5a to 5f and the amplifier 12 that are actually used, the level for each frequency band of the sound immediately after being output from the speakers 5a to 5f is corrected to be flat and natural. Playback sound can be obtained. Furthermore, since the correction value for each frequency band stored in the correction table 14a can be obtained using the HTiB1 itself, no special measuring device is required to obtain the correction value stored in the correction table 14a. become.

  In addition, this invention is not restricted to the structure of the said embodiment, A various deformation | transformation is possible in the range which does not change the meaning of invention. For example, in the above-described embodiment, an example in which the present invention is applied to HTiB 1 has been described. However, the present invention may be applied to an acoustic system such as a sound bar or a rack theater. Moreover, in said embodiment, the microphone 26 distribute | arranged at the position (front and vicinity) of each speaker 5a-5f is connected to HTiB1, and from each speaker 5a-5f actually connected to HTiB1. The correction value for each frequency band stored in the correction table 14a is calculated using the output sound, but the sound output from the speaker of the same model is used as the correction value stored in the correction table. The model data of the correction value calculated for each frequency band may be used. In the above embodiment, the audio signal of the same level is output to the amplifier while being swept in frequency, and the correction value for each frequency band for each speaker is obtained, but white noise is used for each speaker. A correction value for each frequency band may be obtained.

1 HTiB (acoustic system)
5, 5a-5f (speaker)
6 Input terminal (input means)
10 CPU (frequency sweep means, correction value calculation means)
11 DSP (voice signal correction means, frequency sweep means)
12 Amplifier (Audio signal amplification means)
14 Memory (correction table storage means)
14a Correction table 26 Microphone

Claims (3)

Correction table storage means for storing a correction table storing correction values for each frequency band of the input audio signal;
Audio signal correction means for correcting the level of the input audio signal based on the correction value for each frequency band stored in the correction table;
Audio signal amplifying means for amplifying the audio signal level-corrected by the audio signal correcting means;
A speaker that converts the sound signal amplified by the sound signal amplification means into sound and outputs the sound;
In the acoustic system in which the correction table storage unit, the audio signal correction unit, the audio signal amplification unit, and the speaker are set,
The correction value for each frequency band stored in the correction table is a correction value for flatly correcting the level of each frequency band of the output sound from the speaker at a position in front of and near the speaker. An acoustic system characterized by being. Frequency sweeping means for outputting the audio signal at the same level to the audio signal amplification means while sweeping the frequency;
An input means for inputting an input signal from a microphone disposed in front of and in the vicinity of the speaker;
Correction value calculating means for calculating a correction value for each frequency band stored in the correction table,
The correction value calculation means outputs the sound signal from the speaker while performing frequency sweep by outputting the sound signal of the same level to the sound signal amplification means while performing frequency sweep using the frequency sweep means. An input signal corresponding to sound is input from the microphone by the input means, and a correction value for each frequency band is calculated based on a level for each frequency band of the input signal input from the microphone. The acoustic system according to claim 1, wherein the acoustic system is characterized. The number of the speakers is 2 or more,
The acoustic system according to claim 1, wherein the correction table storage unit stores a correction table corresponding to each speaker.

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