JP5064248B2 - Filter characteristic setting apparatus and method, audio system, and program - Google Patents

Description

  The present invention relates to a filter characteristic setting device and method, an audio system, and a program, and more particularly to a filter characteristic setting device and method for setting a filter characteristic of a correction filter means for correcting the characteristic of an audio signal output from a speaker, and the filter. The present invention relates to an audio system including a correction filter unit in which a filter characteristic is set by a characteristic setting device, and a program for setting the filter characteristic.

  In an audio system such as an in-vehicle audio device, it is common to play and listen to radio sound and sound stored in a storage medium such as a CD (Compact Disc) using a speaker installed in the vehicle. is there. In addition, the user enjoys, for example, music in which heavy bass is emphasized by separately connecting a speaker (for example, a subwoofer) that divides a sound range to be reproduced to an audio system according to preference.

  Recently, when an audio system is installed in a vehicle, an audio system that automatically sets output characteristics by outputting a test signal from a speaker and collecting the test signal has appeared (for example, patents). Reference 1). In addition, when there is no subwoofer or when the volume of the subwoofer is set to “OFF”, a technique for switching the acoustic characteristics of other speakers and the connection of the equalizer setting means has also appeared (see, for example, Patent Documents 2 and 3). ).

JP 2006-157597 A JP 2004-40625 A JP 2006-157597 A

  However, in the case of an audio system that automatically sets output characteristics as in Patent Document 1, the ideal acoustic characteristics (target characteristics) are basically no matter what kind of speakers are connected to the audio system. Is unchanged. For this reason, even if the target characteristic is an ideal characteristic from the viewpoint of hearing, the user may be frustrated because the low frequency range is not emphasized even though the subwoofer is connected to the audio system.

  In addition, as described in Patent Documents 2 and 3, when there is no subwoofer or when the volume of the subwoofer is set to “OFF”, a speaker other than the subwoofer is supposed to output a bass range that should be output by the subwoofer. Then, there is a concern that the bass output from the speaker is distorted.

  Therefore, the present invention has been made in view of the above problems, and a filter characteristic setting device and method capable of correcting an audio signal into an appropriate audio signal according to user preferences, and outputting an appropriate audio signal. An object of the present invention is to provide an audio system and a program that can be used.

A filter characteristic setting device for an audio system according to the present invention includes: a frequency characteristic detection unit that outputs a test signal from a speaker of a plurality of audio signal output channels and detects a frequency characteristic of a signal level output from each speaker; A determination means for determining whether or not a plurality of speakers include a subwoofer , and a target characteristic of a frequency characteristic of a signal level output from the plurality of speakers is a low possibility of distortion when each speaker other than the subwoofer outputs. A target characteristic holding unit that holds two types of a first target characteristic in which a frequency band is limited and a second target characteristic in which a lower frequency band is emphasized than the first target characteristic; When it is determined that the plurality of speakers do not include a subwoofer, the first target characteristic is selected, and the plurality of speakers are selected. When it is determined that the subwoofer is included in the speaker, it passes through selection means for selecting the second target characteristic and correction filter means for correcting the characteristic of the audio signal output from each speaker. Each of the corrections based on the frequency characteristics detected by the frequency characteristic detection means so that the total frequency characteristics of the audio signals output from the plurality of speakers become the target characteristics selected by the selection means. Setting means for setting a filter characteristic of the filter means for use.

  According to this, the selection means selects the target characteristic from either the first target characteristic or the second target characteristic depending on whether or not the subwoofer is included in the plurality of speakers, and the setting means Since the filter characteristics of each correction filter means are set so that the frequency characteristics of the total audio signal output from all speakers through the correction filter means become the target characteristics selected by the selection means, When the subwoofer is included in the plurality of speakers, the user can listen to the sound in which the low frequency band is emphasized as compared with the case where the subwoofer is not included. Further, when the subwoofer is not included, the output of the low frequency band is limited as compared with the case where the subwoofer is included, so that it is possible to suppress sound distortion.

  In this case, the determination unit may determine whether the plurality of speakers include a subwoofer based on a frequency characteristic of a signal level output from each speaker detected by the frequency characteristic detection unit. it can. In such a case, since the presence / absence of the subwoofer is determined based on the frequency characteristics of the signal level output by each speaker detected by the frequency characteristic detection means, it is possible to easily determine the presence / absence of the subwoofer. In this case, the frequency characteristic detection means may include a microphone that acquires a test signal output from each speaker.

  The filter characteristic setting device according to the present invention further includes switch means for turning on / off use of the subwoofer, and when the switch means is turned off, the selection means is independent of the judgment of the judgment means. The first target characteristic can be selected as the target characteristic. In such a case, when the use of the subwoofer is turned off, an appropriate filter setting and audio signal correction are performed by setting the same filter characteristics as when the plurality of speakers do not include the subwoofer. It becomes possible.

  The audio system according to the present invention includes a correction filter unit whose filter characteristic is set by the filter characteristic setting device of the present invention, an audio sound source that inputs an audio signal to the correction filter unit, and the correction filter unit. And a speaker for outputting the passed audio signal.

  According to this, since an appropriate filter characteristic is set according to the presence or absence of the subwoofer, the audio signal output from the audio sound source can be appropriately corrected by the correction filter means and output from the speaker. .

The filter characteristic setting method of the present invention includes a frequency characteristic detection step of outputting a test signal from speakers of a plurality of audio signal output channels and detecting frequency characteristics of signal levels output from the speakers, and the plurality of speakers. Determining whether or not a subwoofer is included, and in the determining step, when it is determined that the plurality of speakers do not include a subwoofer , distortion may occur if each speaker other than the subwoofer outputs. When a first target characteristic with a limited low frequency band is selected and it is determined that a subwoofer is included in the speaker, the low frequency band is emphasized more than the first target characteristic. A selection step for selecting the second target characteristic, and the selected target characteristic and the frequency characteristic detection step. The issued on the basis of the frequency characteristic, characterized in that it comprises a and a setting step of setting a filter characteristic of the correction filter means for correcting the characteristics of the audio signals output from the respective speakers.

  According to this, in the selection step, a target characteristic is selected from either the first target characteristic or the second target characteristic depending on whether or not a plurality of speakers include a subwoofer. Since the filter characteristics of each correction filter means are set so that the frequency characteristics of the total audio signal output from all speakers through the correction filter means become the target characteristics selected in the selection step. When the subwoofer is included in the plurality of speakers, the user can listen to the sound in which the low frequency band is emphasized as compared with the case where the subwoofer is not included. In addition, when the subwoofer is not included, the output in the low frequency band is limited as compared with the case where the subwoofer is included, so that it is possible to suppress the distortion of the sound.

  In the filter characteristic setting method of the present invention, in the determination step, it is determined whether or not the speaker includes a subwoofer based on the frequency characteristic of the signal level output from each speaker detected in the frequency characteristic detection step. can do. In such a case, since the presence / absence of the subwoofer is determined based on the frequency characteristics of the signal level output from each speaker detected in the frequency characteristic detection step, it is possible to easily determine the presence / absence of the subwoofer. In this case, the frequency characteristic detection step can be acquired via a microphone that acquires a test signal output from each speaker.

  The filter characteristic setting method of the present invention further includes an on / off determination step of determining whether or not the subwoofer is used. In the selection step, the determination step is performed when the use of the subwoofer is off. The first target characteristic can be selected as the target characteristic regardless of the determination in step (1). In such a case, when the use of the subwoofer is turned off, an appropriate filter setting and audio signal correction are performed by setting the same filter characteristics as when the plurality of speakers do not include the subwoofer. It becomes possible.

According to the program of the present invention, the computer determines whether or not the speaker of the plurality of audio signal output channels includes a subwoofer, and the determination unit determines that the plurality of speakers do not include a subwoofer. When a first target characteristic with a low frequency band limited that may be distorted when each speaker other than the subwoofer outputs is selected and it is determined that the plurality of speakers include a subwoofer , Passing through selection means for selecting a second target characteristic in which a lower frequency band is emphasized than the first target characteristic, and correction filter means for correcting the characteristic of the audio signal output from each speaker. After that, the total audio signal output from each speaker is the target characteristic selected by the selection means. So that, on the basis of the measured values of the frequency characteristic of the signal level each speaker output, characterized in that to the function as a setting unit, which sets the filter characteristics of each correction filter means.

  According to this, the computer selects a target characteristic from either the first target characteristic or the second target characteristic depending on whether or not the subwoofer is included in the plurality of speakers, and sets each correction filter means. Since the filter characteristics of each correction filter means are set so that the frequency characteristics of the total audio signals that pass through and output from all the speakers become the selected target characteristics, the subwoofers are included in the plurality of speakers. In this case, the user can listen to the sound in which the low frequency band is emphasized as compared with the case where the subwoofer is not included. Further, when the subwoofer is not included, the output of the low frequency band is limited as compared with the case where the subwoofer is included, so that the distortion of the sound can be suppressed.

  According to the present invention, it is possible to provide a filter characteristic setting device and method capable of correcting an audio signal into an appropriate audio signal according to a user's preference, an audio system and a program capable of outputting an appropriate audio signal. can do.

  Hereinafter, an audio system according to an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 schematically shows a configuration of an audio system 100 according to an embodiment. As shown in FIG. 1, an audio system 100 includes a sound source 10, an A / D converter 12, a digital signal processor (hereinafter simply referred to as “DSP”) 14, and five power amplifiers 16A _{1 to} 16A _4. 16B and four speakers 18A _{1 to} 18A ₄ . Among them, the speaker 18A ₁ ~18A _{4, 4-channel} speaker system is configured. Further, as shown in FIG. 1, a subwoofer 18B suitable for outputting low-frequency sound can be externally connected to the power amplifier 16B according to the user's preference. When the subwoofer 18B is thus connected, the subwoofer 18B and the 4-channel speaker system described above constitute a 4.1-channel speaker system. In the present embodiment, only one power amplifier 16B is provided. However, the present invention is not limited to this, and a configuration in which two or more subwoofers 18B can be connected by providing two or more power amplifiers 16B. It is also good.

  The sound source 10 is, for example, a radio sound source or a player that reproduces audio information stored in a storage medium such as a CD (compact disc), and the A / D converter 12 converts an analog signal into a digital signal. It is.

As shown in FIG. 1, the DSP 14 includes digital filters 22A _{1 to} 22A ₄ and 22B as correction filter means, D / A converters 24A _{1 to} 24A ₄ and 24B, and switch mechanisms 26A _{1 to} 26A ₄ and 26B. And a TSP (time stretch pulse) generator 28, a CPU 30, and an external memory 32 as a target characteristic holding means.

Among these, the digital filters 22 </ b> A _{1 to} 22 </ b> A ₄ , 22 </ b> B change the filter characteristics under the instruction of the CPU 30, and execute a ripple operation on the signal input from the A / D converter 12. The D / A converters 24A _{1 to} 24A ₄ and 24B convert the digital signals into analog signals and output the analog signals. Under the instruction of the CPU 30, the switch mechanisms 26A _{1 to} 26A ₄ determine whether or not to connect between the digital filters 22A _{1 to} 22A ₄ and the D / A converters 24A _{1 to} 24A ₄ respectively, and the TSP generator 28 It is a switch for setting whether to connect between each of the D / A converters 24A _{1 to} 24A ₄ . Similarly, the switch mechanism 26B also determines whether to connect between the digital filter 22B and the D / A converter 24B under the instruction of the CPU 30, and between the TSP generator 28 and the D / A converter 24B. It is a switch for setting whether to connect between.

When the TSP generator 28 is connected to any of the D / A converters 24A _{1 to} 24A ₄ or 24B by the switch mechanism 26A _{1 to} 26A ₄ or 26B, the TSP generator 28 outputs a time stretch pulse as a test signal for measuring acoustic characteristics. It is what happens.

The CPU 30 comprehensively controls the entire DSP 14 and changes (sets) the filter characteristics of the digital filters 22A _{1 to} 22A ₄ and 22B as described above. Note that specific processing by the CPU 30 will be described in detail later.

The external memory 32 has a target curve 1 (FIG. 2 (a) having normal characteristics as target frequency characteristic data of the entire speaker and subwoofer required for determining the filter characteristics of the digital filters 22A _{1 to} 22A ₄ and 22B. )) And a target curve 2 (see FIG. 2B) in which a lower frequency band is emphasized than the target curve 1.

The power amplifiers 16A _{1 to} 16A ₄ and 16B amplify analog signals output from the D / A converters 24A _{1 to} 24A ₄ and 24B of the DSP 14. The speakers 18A _{1 to} 18A ₄ are installed on the front left (FL), front right (FR), rear left (RL), and rear right (RR) in the vehicle, respectively. Further, when the subwoofer 18B is installed, for example, the rear central portion of the vehicle is installed (the speaker 18A ₃ of the rear left (RL), between the speaker 18A ₄ of the rear right (RR)).

In the audio system 100 of the present embodiment configured as described above, the frequency characteristic measurement unit 40 can be connected to the A / D converter 12 from the outside, as indicated by a dotted line in FIG. The frequency characteristic measurement unit 40 includes a microphone 42 and a microphone amplifier 44. The microphone 42 is for collecting test signals output from the speakers 18A _{1 to} 18A ₄ and the subwoofer 18B, and the microphone amplifier 44 is for amplifying an analog signal input from the microphone 42. According to the frequency characteristic measuring unit 40, when the time stretch pulse generated in TSP generator 28 is output from either of the speakers 18A ₁ ~18A ₄ and subwoofer 18B, picks up and amplifies the output signal sound be able to. This output signal sound is used when setting the filter characteristics of digital filters 22A _{1 to} 22A ₄ and 22B described later.

Next, a method for setting the filter characteristics of the digital filters 22A _{1 to} 22A ₄ and 22B will be described with reference to the flowchart of FIG. Note that the processing of FIG. 3 is executed by the CPU 30 shown in FIG. Therefore, in the following description, the description of the subject of processing is omitted unless particularly necessary.

  Further, as a premise of processing, the subwoofer 18B is connected to the power amplifier 16B (that is, the audio system 100 is equipped with a 4.1 channel speaker system), and is connected to the A / D converter 12 in advance. On the other hand, it is assumed that the frequency characteristic measurement unit 40 is connected by a user or an operator of a card dealer, and the microphone 42 of the frequency characteristic measurement unit 40 is installed at a predetermined position in the vehicle.

First, in step S10 in FIG. 3, the parameter n representing the channel of the speaker is set to 1, and the subwoofer flag is set to OFF. In this embodiment, it is assumed that there are 1 to 5 speaker channels, channel 1 = front left (FL) speaker 18A ₁ , channel 2 = front right (FR) speaker 18A ₂ , channel 3 = rear left (RL). It is assumed that speaker 18A ₃ , channel 4 = rear right (RR) speaker 18A ₄ , channel 5 = subwoofer 18B.

  In the next step S12, it is determined whether or not the process is finished. Here, the determination is made based on whether or not the parameter n is larger than a predetermined number (in this embodiment, the number of channels “5”) (whether n> 5). In this case, since n = 1, the determination is negative and the process proceeds to the next step S14.

In the next step S14, the D / A converter 24A ₁ and the TSP generator 28 are connected using the channel n switch mechanism (here, the switch mechanism 26A ₁ ), and the other channels (n = 2 to 5). The D / A converters 24A _{2 to} 24A ₄ and 24B and the TSP generator 28 are disconnected using the switch mechanisms 26A _{2 to} 26A ₄ and 26B.

  Next, in step S16, the TSP generator 28 is caused to generate a time stretch pulse as an acoustic characteristic measurement test signal.

Next, in step S18, the test tone output from the speaker 18A ₁ and picked up by the microphone 42, together with the A / D converter 12 a digital signal converted signal to CPU30 is received in is amplified by the microphone amplifier 44 To do. Then, the CPU 30 obtains frequency characteristic data of the FL speaker 18A ₁ in the passenger compartment by performing FFT (Fast Fourier Transform) processing or the like on the received signal. In this case, the frequency characteristics of the test tone output from the FL speaker 18A ₁ is a characteristic as having a certain level of the signal level over the entire frequency band.

  Next, in step S20, based on the frequency characteristic data acquired in step S18, it is determined whether or not the channel 1 speaker is a subwoofer. Here, whether or not it is a subwoofer is determined based on whether it has a high signal level only in the low frequency band, or whether it has a certain level or more over the entire frequency band. Here, since the signal level exceeds a certain level over the entire frequency band, it is determined not to be a subwoofer (determination here is denied), and the process proceeds to step S22.

  In step S22, n is incremented by 1 (n ← 2), and then the process returns to step S12.

Thereafter, the frequency of the FR speaker 18A ₂ , the RL speaker 18A ₃ , and the RR speaker 18A ₄ is repeated by repeating steps S12 → S14 → S16 → S18 → S20 → S22 while n = 2, n = 3, and n = 4. The characteristic data is acquired (step S18), and it is determined whether the subwoofer is used (step S20). If n = 2 to 4, all the determinations in step S20 are denied.

  When n = 4, n is incremented by 1 (n ← 5) in step S22, and when the process returns to step S12, an end determination is made in step S12 based on whether n is greater than 5. In this case, since n = 5, the determination here is denied, and the process proceeds to the next step S14. In step S14, the switch mechanism 26B of the channel 5 is used to connect the TSP generator 28 and the D / A converter 24B.

  Thereafter, in step S16, an acoustic characteristic measurement test signal (TSP) is generated from the TSP generator 28, and in step S18, the signal converted into the digital signal is received, whereby the frequency characteristic data of the subwoofer 18B in the vehicle interior is received. To get. In this case, the frequency characteristic of the test signal sound output from the subwoofer 18B has a high signal level only in the low frequency band.

  Next, in step S20, based on the frequency characteristic data acquired in step S18, it is determined whether or not the channel 5 speaker is a subwoofer. In this case, since the frequency characteristic data has a high signal level only in the low frequency band, it is determined to be a subwoofer (the determination here is affirmed), and after setting the subwoofer flag to ON in step S24. Then, the process proceeds to step S22 again.

  Then, after n is incremented by 1 (n ← 6) in step S22, the process returns to step S12. In step S12, it is determined whether or not to end depending on whether or not n> 5. Here, since n = 6, the determination is affirmed and the process proceeds to step S26.

  In the next step S26, it is determined whether or not the subwoofer flag is ON. In this case, since the subwoofer flag is ON in step S24 executed when n = 5, the determination here is affirmed and the process proceeds to step S30.

  In step S30, the target curve 2 shown in FIG. 2B in which the low frequency band is emphasized is read from the external memory 32 and set as the target frequency characteristic (target frequency characteristic) of the audio system 100.

Thereafter, the process proceeds to step S32, and the CPU 30 performs step so that the total audio signal (sound) output from all the speakers and subwoofers of the audio system 100 matches the set target characteristic (target curve 2). Using the frequency characteristic data of each speaker and subwoofer actually measured in the vehicle interior in S16 and S18, the filter characteristics of the digital filters 22A _{1 to} 22A ₄ and 22B are set, and the filter characteristic setting process of this embodiment is completed. .

If the subwoofer 18B is not connected to the power amplifier 16B, that is, if the audio system 100 is a 4-channel speaker system, the frequency characteristic data is obtained in step S18 executed when n = 5. Since it cannot be acquired, the determination in step S20 is denied. In this case, since there is no subwoofer in the audio system 100, the subwoofer flag remains OFF at the time of step S26. Accordingly, since the determination here is negative, in step S28, the target curve 1 shown in FIG. 2A, which is a normal filter characteristic, is used as the target frequency characteristic (target frequency characteristic) of the audio system 100 in the external memory. Read from 32 and set. In step S32, the CPU 30 executes step S16 so that the total audio signal (sound) output from the speakers 18A _{1 to} 18A ₄ of the audio system 100 matches the set target characteristic (target curve 1). The filter characteristics of the digital filters 22A _{1 to} 22A ₄ and 22B are set using the frequency characteristic data of each speaker and subwoofer actually measured in the vehicle interior in S18.

  As is apparent from the above description, in the present embodiment, the CPU 30 constitutes the determination means, selection means, and setting means of the present invention. Further, the TSP generator 28 and the frequency characteristic measuring unit 40 of the present embodiment constitute the frequency characteristic detecting means of the present invention. Further, the CPU 30, TSP generator 28, external memory 32, and frequency characteristic measurement unit 40 of the present embodiment constitute a filter characteristic setting device of the present invention.

As described above, according to the present embodiment, the CPU 30 outputs the test signal (TSP) from a plurality of speakers (and subwoofers), acquires frequency characteristic data of the signal level, and based on the frequency characteristic data. Then, it is determined whether or not a subwoofer is connected to the audio system 100. If the subwoofer is not connected as a result of the determination, the target frequency characteristic is set to the target curve 1. If the subwoofer is connected, the target frequency characteristic is set to the target curve 2. Set. In addition, the CPU 30 passes through the digital filters 22A _{1 to} 22A ₄ and 22B, and measures each of the audio signals actually measured in the vehicle interior so that the total frequency characteristic of the audio signal output from the speaker or subwoofer matches the set target curve. The filter characteristics are set using the frequency characteristic data of the speaker and the subwoofer. As described above, in the present embodiment, when the subwoofer 18B is connected to the audio system 100, it is possible to output a sound in which the low frequency band is emphasized as compared with the case where the subwoofer is not included. Thereby, the user can listen to the sound that suits his / her preference. Further, when a subwoofer is not connected to the audio system 100, the output in the low frequency band is limited as compared with the case where the subwoofer is included, so that the low frequency band is forcibly output only by speakers other than the subwoofer. Therefore, the occurrence of sound distortion and the like can be suppressed.

  In this embodiment, since the presence or absence of the subwoofer is determined based on the actually detected frequency characteristics, it is possible to easily determine the presence or absence of the subwoofer without preparing a separate detection system for detecting the connection state of the speaker. Is possible. However, the present invention is not limited to this, and the connection state of the speaker may be detected by another detection system.

  In the above embodiment, a switch for turning on / off use of the subwoofer 18B may be provided. In this case, when the user turns off the switch, the CPU 30 can set the target characteristic to the target curve 1 regardless of the target characteristic already set. By doing in this way, when the subwoofer 18B is off, it is possible to prevent the low frequency band sound to be output by the subwoofer from being forcibly output to other speakers. Thereby, generation | occurrence | production of distortion etc. of a sound can be suppressed.

  In the above embodiment, the case where one of the two target curves shown in FIGS. 2A and 2B is set as the target characteristic has been described. However, the present invention is not limited to this. For example, FIG. ) Is a target curve 1 (normal characteristic), and the target curve shown in FIG. 4B in which the low frequency band is emphasized more than that in FIG. 4A is the target curve 2 (low frequency emphasis). ).

  In the above embodiment, the case where the correction filter means is applied to a digital filter has been described. However, the present invention is not limited to this. For example, an analog filter, an IIR filter (infinite impulse response filter), an FIR filter (finite) It is also possible to apply to an impulse response filter.

  In the above-described embodiment, the case where the determination unit, the selection unit, and the setting unit of the present invention are implemented by the program of the CPU 30 has been described. It may be realized by hardware.

  In the above embodiment, the case where the audio system of the present invention is mounted on a vehicle has been described. However, the present invention is not limited to this, and the audio system of the present invention can be adopted as an audio system arranged in various spaces. Is possible.

  The above-described embodiment is an example of a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

1 is a diagram schematically showing a configuration of an audio system according to an embodiment. It is a figure which shows an example of the target curves 1 and 2. FIG. It is a flowchart for demonstrating a series of flows of the setting process of the filter characteristic which concerns on one Embodiment. It is a figure which shows another example of the target curves 1 and 2. FIG.

Explanation of symbols

18A _{1 to} 18A ₄ speaker 18B subwoofer 22A _{1 to} 22A ₄ digital filter (correction filter means)
22B Digital filter (correction filter means)
28 TSP generator (part of frequency characteristic detection means)
30 CPU (determination means, selection means, setting means)
32 External memory (target characteristic holding means)
40 Frequency characteristic measurement unit (part of frequency characteristic detection means)
42 Microphone
100 audio system

Claims (10)

A frequency characteristic detecting means for outputting a test signal from a speaker of a plurality of audio signal output channels and detecting a frequency characteristic of a signal level output from each speaker;
Determining means for determining whether or not the plurality of speakers include a subwoofer;
As the target characteristics of the frequency characteristics of the signal level output from the plurality of speakers, a first target characteristic in which a low frequency band that may be distorted when output from each speaker other than the subwoofer is limited , and the first target characteristic Target characteristic holding means for holding two types of the second target characteristic in which the lower frequency band is emphasized than the above,
When the determination means determines that the plurality of speakers do not include a subwoofer, the first target characteristic is selected, and when it is determined that the plurality of speakers include a subwoofer, Selecting means for selecting the second target characteristic;
The total frequency characteristics of the audio signals output from the plurality of speakers through the correction filter means for correcting the characteristics of the audio signals output from the speakers are the target characteristics selected by the selection means. A filter characteristic setting device for an audio system comprising: setting means for setting the filter characteristic of each correction filter means based on the frequency characteristic detected by the frequency characteristic detection means. The determination means determines whether or not the plurality of speakers include a subwoofer based on a frequency characteristic of a signal level output from each speaker detected by the frequency characteristic detection means. Item 2. The filter characteristic setting device for an audio system according to Item 1. 3. The filter characteristic setting device for an audio system according to claim 2, wherein the frequency characteristic detection unit includes a microphone that acquires a test signal output from each speaker. Further comprising switch means for turning on or off the use of the subwoofer;
4. When the switch unit is turned off, the selection unit selects the first target characteristic as a target characteristic regardless of the determination of the determination unit. The filter characteristic setting device for an audio system according to one item. The correction filter means in which the filter characteristic is set by the filter characteristic setting device according to any one of claims 1 to 4,
An audio source that inputs an audio signal to the correction filter means;
An audio system comprising: a speaker that outputs an audio signal that has passed through the correction filter means. A frequency characteristic detecting step of outputting a test signal from a speaker of a plurality of audio signal output channels and detecting a frequency characteristic of a signal level output from each speaker;
A determination step of determining whether or not a subwoofer is included in the plurality of speakers;
In the determination step, when it is determined that the plurality of speakers do not include a subwoofer, a first target characteristic in which a low frequency band that may be distorted when each speaker other than the subwoofer is output is limited. Selecting and selecting a second target characteristic in which a lower frequency band is emphasized than the first target characteristic when it is determined that a subwoofer is included in the speaker;
A setting step for setting a filter characteristic of a correction filter means for correcting the characteristic of the audio signal output from each speaker based on the selected target characteristic and the frequency characteristic detected in the frequency characteristic detection step; A filter characteristic setting method for an audio system including 7. The determining step includes determining whether or not the speaker includes a subwoofer based on a frequency characteristic of a signal level output from each speaker detected in the frequency characteristic detecting step. The filter characteristic setting method of the audio system as described in 2. The audio system filter characteristic setting method according to claim 7, wherein the frequency characteristic detection step acquires a test signal output from each speaker via a microphone. An on / off determination step of determining whether to use the subwoofer;
9. The method according to claim 6, wherein, in the selection step, the first target characteristic is selected as a target characteristic in a state where use of the subwoofer is turned off regardless of the determination in the determination step. An audio system filter characteristic setting method according to claim 1. Computer
A determination means for determining whether or not the subwoofer is included in the speakers of the plurality of audio signal output channels;
When the determining means determines that the plurality of speakers do not include a subwoofer, the first target characteristic is selected in which a low frequency band that may be distorted when each speaker other than the subwoofer outputs is limited. Selection means for selecting a second target characteristic in which a lower frequency band is emphasized than the first target characteristic when it is determined that the plurality of speakers include a subwoofer; and Each speaker so that the total audio signal output from each speaker becomes the target characteristic selected by the selection means after passing through each of the correction filter means for correcting the characteristics of the output audio signal. Setting means for setting the filter characteristics of each of the correction filter means based on the actually measured value of the frequency characteristics of the signal level output by A program characterized by functioning as a stage.

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