Patent Publication Number: US-2023144494-A1

Title: Audio signal processing device, audio signal processing method, and recording medium

Description:
CROSS-REFERENCE OF RELATED APPLICATIONS 
     This application is the U.S. National Phase under 35 U.S.C. § 371 of International Patent Application No. PCT/JP2021/025732, filed on Jul. 8, 2021, which in turn claims the benefit of Japanese Patent Application No. 2020-133324, filed on Aug. 5, 2020, the entire disclosures of which applications are incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to audio signal processing devices, audio signal processing methods, and recording media. 
     BACKGROUND ART 
     Patent Literature (PTL) 1 discloses a portable terminal device which can perform audio output correction corresponding to earphones that are connected. The portable terminal device uses audio signals for test to measure the impedance of the earphones connected to earphone connection terminals, and performs low-frequency boost correction according to the resulting characteristics to individually correct, according to the characteristics of the earphones, the characteristics of the output sound thereof. 
     CITATION LIST 
     Patent Literature 
     [PTL 1] Japanese Unexamined Patent Application Publication No. 2010-226329 
     SUMMARY OF INVENTION 
     Technical Problem 
     In PTL 1, when the earphones are connected to the portable terminal device, the portable terminal device measures and records a correction parameter for the earphones to perform automatic switching. In a case where this technique is applied to a system having a function in which a user can change settings on audio signal processing to settings desired by the user, when the settings are changed after the measurement of the correction parameter, in order to realize sound quality with the settings desired by the user, it is necessary to reset the settings as in the measurement of the correction parameter. Hence, disadvantageously, the convenience of the user is significantly lowered. 
     The present disclosure provides an audio signal processing device which can perform, without impairing the convenience of a user, audio signal processing using a correction parameter obtained by performing a measurement with settings desired by the user and the like. 
     Solution to Problem 
     An audio signal processing device in the present disclosure is an audio signal processing device that performs audio signal processing on an audio signal reproduced in a record player, the audio signal processing device includes: a first input terminal that receives the audio signal from the record player; a memory that stores a correction parameter for the audio signal processing on the audio signal and characteristic information indicating a characteristic of an audio signal for measurement; a signal processing circuit that performs, based on the correction parameter stored in the memory, the audio signal processing on the audio signal received from the first input terminal; and a microcomputer, and the microcomputer measures, when the audio signal for measurement recorded on a phonograph record for measurement is reproduced by the record player, a sound characteristic of an audio signal received by the first input terminal from the record player, generates, based on a result of comparison between a result of the measurement performed by the microcomputer and the characteristic information stored in the memory, the correction parameter for the audio signal processing in the signal processing circuit, and stores, in the memory, setting information and the correction parameter generated, in association with each other, the setting information indicating a setting on the audio signal processing in the audio signal processing device when the measurement is performed. 
     An audio signal processing method in the present disclosure is an audio signal processing method performed in an audio signal processing device that performs audio signal processing on an audio signal reproduced in a record player, and the audio signal processing method includes: measuring, when an audio signal for measurement recorded on a phonograph record for measurement is reproduced by the record player, a sound characteristic of the audio signal received from the record player; generating, based on a result of comparison between a result of the measurement performed and characteristic information stored in a memory included in the audio signal processing device and indicating a characteristic of the audio signal for measurement, a correction parameter for the audio signal processing; and storing, in the memory, setting information and the correction parameter generated, in association with each other, the setting information indicating a setting on the audio signal processing in the audio signal processing device when the measurement is performed. 
     These general or specific aspects may be realized by a system, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM or may be realized by any combination of a system, a method, an integrated circuit, a computer program, and a recording medium. 
     Advantageous Effects of Invention 
     An audio signal processing device in the present disclosure can perform, without impairing the convenience of a user, audio signal processing using a correction parameter obtained by performing a measurement with settings desired by the user. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a schematic diagram showing the configuration of a record reproduction system in an embodiment. 
         FIG.  2    is a block diagram showing the configuration of the record reproduction system in the embodiment. 
         FIG.  3    is a flowchart showing the operation of measurement processing performed by an audio signal processing device in the embodiment. 
         FIG.  4    is a diagram showing an example of a plurality of sound settings stored in a memory in the embodiment. 
         FIG.  5    is a flowchart showing the operation of sound setting application processing performed by the audio signal processing device in the embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     An audio signal processing device according to an aspect of the present disclosure is an audio signal processing device that performs audio signal processing on an audio signal reproduced in a record player, the audio signal processing device includes: a first input terminal that receives the audio signal from the record player; a memory that stores a correction parameter for the audio signal processing on the audio signal and characteristic information indicating a characteristic of an audio signal for measurement; a signal processing circuit that performs, based on the correction parameter stored in the memory, the audio signal processing on the audio signal received from the first input terminal; and a microcomputer, and the microcomputer measures, when the audio signal for measurement recorded on a phonograph record for measurement is reproduced by the record player, a sound characteristic of an audio signal received by the first input terminal from the record player, generates, based on a result of comparison between a result of the measurement performed by the microcomputer and the characteristic information stored in the memory, the correction parameter for the audio signal processing in the signal processing circuit, and stores, in the memory, setting information and the correction parameter generated, in association with each other, the setting information indicating a setting on the audio signal processing in the audio signal processing device when the measurement is performed. 
     In this way, the audio signal processing device according to the present embodiment stores, in the memory, the setting information and the correction parameter generated, in association with each other, the setting information indicating the setting on the audio signal processing in the audio signal processing device when the measurement is performed. Hence, for example, when a user operates the audio signal processing device to select and set the correction parameter and the setting information stored in the memory in association with each other, the user can also automatically make the setting for the audio signal processing device based on the setting information in conjunction with the setting for the correction parameter. Therefore, it is possible to perform, without impairing the convenience of the user, the audio signal processing using the correction parameter obtained by performing the measurement with the setting desired by the user, with the result that desired sound quality can easily be realized. 
     Preferably, the microcomputer reads the correction parameter stored in the memory and the setting information stored in the memory in association with the correction parameter, controls the audio signal processing device with the setting indicated by the setting information read, and causes the signal processing circuit to perform the audio signal processing using the correction parameter read. 
     In this way, the audio signal processing device according to the present embodiment stores, in the memory, the setting information and the correction parameter generated, in association with each other, the setting information indicating the setting on the audio signal processing in the audio signal processing device when the measurement is performed. Then, when the audio signal processing device selects and sets the correction parameter and the setting information stored in the memory in association with each other, the audio signal processing device also automatically makes the setting for the audio signal processing device based on the setting information in conjunction with the setting for the correction parameter. Therefore, it is possible to perform, without impairing the convenience of the user, the audio signal processing using the correction parameter obtained by performing the measurement with the setting desired by the user, with the result that desired sound quality can easily be realized. 
     Preferably, the audio signal processing device further includes: a second input terminal that receives an input of the audio signal from the record player; and a selector that selects, from the first input terminal and the second input terminal, one input terminal for receiving the audio signal, the setting information includes selector information indicating the one input terminal selected by the selector when the measurement is performed, the microcomputer causes the selector to select the one input terminal indicated by the selector information included in the setting information read, and the signal processing circuit performs, on the audio signal received by the one input terminal selected by the selector, the audio signal processing using the correction parameter read together with the setting information. 
     Hence, when the input terminal selected by the selector is different from the input terminal indicated by the selector information included in the setting information read, the input terminal indicated by the selector information is caused to be selected by the selector. As described above, when the setting indicated by the setting information read is different from the current setting in the audio signal processing device, the setting is changed to the setting indicated by the setting information, and thus it is possible to also automatically make the setting for the audio signal processing device based on the setting information in conjunction with the setting for the correction parameter. Therefore, the convenience of the user is enhanced. 
     Preferably, the audio signal processing device further includes: a second input terminal that receives an input of the audio signal from the record player; a selector that selects, from the first input terminal and the second input terminal, one input terminal for receiving the audio signal; and a presenter that presents a message, the setting information includes selector information indicating the one input terminal selected by the selector when the measurement is performed, and the microcomputer causes, when the one input terminal indicated by the selector information included in the setting information read is different from an input terminal selected by the selector, the presenter to present a message indicating that an input terminal different from the one input terminal is selected by the selector. 
     Hence, it is possible to provide a notification to the user that the input terminal different from the one input terminal is selected by the selector. 
     Preferably, the message includes a message that prompts a user to provide an input for causing the selector to switch to the one input terminal. 
     Hence, it is possible to prompt the user to provide an input for causing the selector to switch to the one input terminal. 
     Preferably, the audio signal processing includes first amplification processing that is performed on an audio signal after analog-digital conversion, the setting information includes a first gain that is set for the first amplification processing, and the signal processing circuit performs the first amplification processing with the first gain included in the setting information read. 
     Hence, when the first gain set for the first amplification processing performed by the signal processing circuit is different from the first gain included in the setting information read, the gain for the first amplification processing is updated to the first gain included in the setting information read. As described above, when the setting indicated by the setting information read is different from the current setting in the audio signal processing device, the setting is changed to the setting indicated by the setting information, and thus it is possible to also automatically make the setting for the audio signal processing device based on the setting information in conjunction with the setting for the correction parameter. Therefore, the convenience of the user is enhanced. 
     Preferably, the audio signal processing device further includes: an amplification processing circuit that performs second amplification processing on the audio signal received by the first input terminal; and a receiver that receives an input from a user, the setting information includes cartridge information indicated by the input received by the receiver and indicating a type of cartridge included in the record player, and the microcomputer causes the amplification processing circuit to perform the second amplification processing with a second gain corresponding to the type of cartridge indicated by the cartridge information included in the setting information read. 
     Hence, when the type of cartridge set for the audio signal processing device is different from the type of cartridge indicated by the cartridge information included in the setting information read, the setting for the audio signal processing device is updated to the type of cartridge indicated by the cartridge information. In this way, the microcomputer updates, according to the updated setting, the second gain for the second amplification processing performed by the amplification processing circuit. As described above, when the setting indicated by the setting information read is different from the current setting in the audio signal processing device, the setting is changed to the setting indicated by the setting information, and thus it is possible to also automatically make the setting for audio signal processing device  100  based on the setting information in conjunction with the setting for the correction parameter. Therefore, the convenience of the user is enhanced. 
     An audio signal processing method in the present disclosure is an audio signal processing method performed in an audio signal processing device that performs audio signal processing on an audio signal reproduced in a record player, and the audio signal processing method includes: measuring, when an audio signal for measurement recorded on a phonograph record for measurement is reproduced by the record player, a sound characteristic of the audio signal received from the record player; generating, based on a result of comparison between a result of the measurement performed and characteristic information stored in a memory included in the audio signal processing device and indicating a characteristic of the audio signal for measurement, a correction parameter for the audio signal processing; and storing, in the memory, setting information and the correction parameter generated, in association with each other, the setting information indicating a setting on the audio signal processing in the audio signal processing device when the measurement is performed. 
     In this way, in the audio signal processing method according to the present embodiment, the setting information indicating the setting on the audio signal processing in the audio signal processing device when the measurement is performed is stored in the memory in association with the correction parameter generated. Hence, for example, when the user operates the audio signal processing device to select and set the correction parameter and the setting information stored in the memory in association with each other, the user can also automatically make the setting for the audio signal processing device based on the setting information in conjunction with the setting for the correction parameter. Therefore, it is possible to perform, without impairing the convenience of the user, the audio signal processing using the correction parameter obtained by performing the measurement with the setting desired by the user, with the result that desired sound quality can easily be realized. 
     These general or specific aspects may be realized by a system, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM or may be realized by any combination of a system, a method, an integrated circuit, a computer program, and a recording medium. 
     Embodiments will be described in detail below with reference to drawings as necessary. However, a detailed description beyond necessity may be omitted. For example, a detailed description of an already well known matter or a repeated description of substantially the same configuration may be omitted. This is intended to prevent the following description from being unnecessarily redundant and facilitate the understanding of a person skilled in the art. 
     The accompanying drawings and the following description are provided so that the person skilled in the art fully understands the present disclosure, and are not intended to limit the subject matter of the claims. 
     Embodiment 
     [1-1. Configuration] 
       FIG.  1    is a schematic diagram showing the configuration of a record reproduction system in an embodiment.  FIG.  2    is a block diagram showing the configuration of the record reproduction system in the embodiment. 
     As shown in these figures, record reproduction system  1  is a system for reproducing an analog record (hereinafter referred to as phonograph record  15 ), and includes record player  10 , audio signal processing device  100 , and speakers  107 . In  FIG.  1   , remote controller  120  is shown which transmits, to audio signal processing device  100 , a control signal for indicating control in audio signal processing device  100 . 
     Record player  10  is an audio device which reproduces signals (for example, audio signals) recorded on phonograph record  15 , and includes turntable  11 , cartridge  12 , and tone arm  13 . 
     Turntable  11  is a rotary stage on which phonograph record  15  is placed, and rotates (spins) at a constant speed in a predetermined rotation direction when phonograph record  15  is reproduced. 
     Cartridge  12  is a pickup cartridge which includes a phonograph needle. Cartridge  12  is interchangeably provided at a tip of tone arm  13 . The phonograph needle of cartridge  12  traces the sound groove of phonograph record  15  placed on rotating turntable  11  when phonograph record  15  is reproduced. There are various types of cartridges  12  such as a moving magnet type (MM type) and a moving coil type (MC type) depending on the difference in the structure thereof. Cartridge  12  acquires, as vibrations, signals recorded on the sound groove of phonograph record  15  via the phonograph needle. Cartridge  12  uses a magnet or a coil included in cartridge  12  to convert the vibrations acquired via the phonograph needle into analog electrical signals, and outputs, as audio signals, the electrical signals obtained by the conversion. In cartridge  12 , the sound characteristics and the signal levels of the audio signals obtained are different according to the type of cartridge  12 . The sound characteristics in the present disclosure include a frequency characteristic and a phase characteristic. 
     Tone arm  13  holds cartridge  12  at the tip, appropriately controls a pressure applied between the phonograph needle of cartridge  12  and phonograph record  15  rotating on turntable  11 , and performs control such that the phonograph needle smoothly traces the sound groove of rotating phonograph record  15 . 
     Record player  10  can transmit, to audio signal processing device  100 , the audio signals output by cartridge  12  using a plurality of transmission paths. In the present embodiment, record player  10  includes a first output terminal (not shown) to which first transmission cable  21  is connected and which outputs the audio signals and a second output terminal (not shown) to which second transmission cable  22  is connected and which outputs the audio signals. Hence, record player  10  can transmit the audio signals by the transmission paths of first transmission cable  21  and second transmission cable  22 . First transmission cable  21  is, for example, an RCA cable. Second transmission cable  22  is, for example, an XLR cable. As long as transmission cables  21  and  22  are cables capable of transmitting the audio signals to audio signal processing device  100 , they are not limited to the RCA cable and the XLR cable described as examples. For example, one of first transmission cable  21  and second transmission cable  22  may be another cable such as an AUX cable. First transmission cable  21  and second transmission cable  22  are different types of cables, and the transmission paths of transmission cables  21  and  22  differ from each other in sound characteristics. Hence, the audio signals which have passed through these transmission paths differ from each other in sound characteristics. 
     Audio signal processing device  100  is a device which performs audio signal processing on the audio signals reproduced in record player  10 . Audio signal processing device  100  specifically performs adjustment processing on the sound characteristics of the audio signals from record player  10  and amplification processing on the audio signals. Audio signal processing device  100  outputs, to speakers  107 , the audio signals on which the audio signal processing has been performed. Audio signal processing device  100  may be, for example, an amplification device. As shown in  FIG.  2   , audio signal processing device  100  includes signal processing circuit  101 , memory  102 , phono equalizer  103 , A/D converter  104 , D/A converter  105 , amplifier  106 , microcomputer  108 , display device  109 , input interface (IF)  110 , selector  111 , input terminal  112 , and communication IF  113 . 
     Input terminal  112  is a terminal which receives the audio signals from record player  10 . Input terminal  112  includes first input terminal  112   a  and second input terminal  112   b . First input terminal  112   a  is, for example, a terminal of PHONO (RCA), and first transmission cable  21  is connected to first input terminal  112   a . Second input terminal  112   b  is, for example, a terminal of PHONO (XLR), and second transmission cable  22  is connected to second input terminal  112   b . First input terminal  112   a  and second input terminal  112   b  are different types of terminals. First input terminal  112   a  is preferably a terminal corresponding to first transmission cable  21  and is not limited to the terminal of PHONO (RCA). Likewise, second input terminal  112   b  is preferably a terminal corresponding to second transmission cable  22  and is not limited to the terminal of PHONO (XLR). For example, one of first input terminal  112   a  and second input terminal  112   b  may be an AUX terminal. 
     Selector  111  selects one input terminal for receiving the audio signals from first input terminal  112   a  and second input terminal  112   b . Selector  111  selects, by control of microcomputer  108 , one of first input terminal  112   a  and second input terminal  112   b , that is, one of the terminal of PHONO (RCA) and the terminal of PHONO (XLR), and outputs, to phono equalizer  103 , the analog audio signals received by the selected terminal. 
     Phono equalizer  103  is an equalizer which preforms the amplification processing on the analog audio signals received from selector  111  and correction processing on the frequency amplitude characteristic of the audio signals. Specifically, phono equalizer  103  amplifies, with a set gain, the analog audio signals which are input. This gain is a gain for amplifying the analog audio signals obtained from record player  10  and is set by microcomputer  108 . In order to reproduce original sound recorded on phonograph record  15 , phono equalizer  103  performs correction (reverse correction) with characteristics reverse to correction which is performed when the original sound is recorded on the phonograph record. Phono equalizer  103  outputs, to A/D converter  104 , the audio signals on which the amplification processing and the correction processing have been performed. Phono equalizer  103  is an example of an amplification processing circuit. The amplification processing performed by phono equalizer  103  is an example of second amplification processing. The gain used in the amplification processing performed by phono equalizer  103  is an example of a second gain. 
     A/D converter  104  is a converter which converts the analog audio signals received from phono equalizer  103  into digital audio signals. A/D converter  104  outputs the digital audio signals after the conversion to signal processing circuit  101 . 
     Signal processing circuit  101  performs, by control of microcomputer  108 , various types of audio signal processing on the digital audio signals received from A/D converter  104 . The audio signal processing includes adjustment processing on the sound characteristics of the digital audio signals and amplification processing on the audio signals. Signal processing circuit  101  is, for example, a digital signal processor (DSP). Signal processing circuit  101  can analyze the sound characteristics of the digital audio signals. Signal processing circuit  101  reads, by control from microcomputer  108 , correction parameters for various types of audio signal processing from memory  102 , and performs the audio signal processing on the digital audio signals based on the correction parameters read. For example, signal processing circuit  101  may read, from memory  102 , a correction parameter for the adjustment processing on the sound characteristics of the digital audio signals to perform the adjustment processing based on the correction parameter. Signal processing circuit  101  may perform, with a set gain, the amplification processing on the digital audio signals which are input. This gain is a gain for amplifying the digital audio signals, and is set by microcomputer  108 . The amplification processing performed by signal processing circuit  101  is an example of first amplification processing. The gain used in the amplification processing performed by signal processing circuit  101  is an example of a first gain. The gain used in the amplification processing performed by signal processing circuit  101  is different from the gain used in the amplification processing performed by phono equalizer  103 . Signal processing circuit  101  outputs, to D/A converter  105 , the digital audio signals on which the audio signal processing has been performed. 
     D/A converter  105  is a converter that converts, into analog audio signals, the digital audio signals whose sound characteristics have been adjusted by signal processing circuit  101 . D/A converter  105  outputs, to amplifier  106 , the analog audio signals after the conversion. 
     Amplifier  106  is an amplifier which amplifies the analog audio signals received from D/A converter  105 . Amplifier  106  may be, for example, a class D amplifier or may be an amplifier of another class. The analog audio signals amplified by amplifier  106  are output to speakers  107  via speaker cables  31  and  32  connected to audio signal processing device  100 . 
     Memory  102  is formed with a random access memory (RAM), a flash read only memory (ROM) or the like, and stores various types of information. Specifically, memory  102  stores programs which are executed by microcomputer  108 . Memory  102  also stores correction parameters for the audio signal processing on the audio signals. Memory  102  also stores characteristic information indicating the characteristics of audio signals for measurement. Memory  102  also stores setting information indicating settings on the audio signal processing in audio signal processing device  100 . 
     Microcomputer  108  is a controller which exchanges control signals between signal processing circuit  101 , memory  102 , phono equalizer  103 , display device  109 , input IF  110 , selector  111 , and communication IF  113 . Microcomputer  108  executes the programs stored in memory  102  to perform various types of processing, and thereby controls the operations of signal processing circuit  101 , memory  102 , phono equalizer  103 , display device  109 , selector  111 , and communication IF  113 . Microcomputer  108  may perform the various types of processing according to input signals (operation signals) received by input IF  110  or input signals (operation signals) received from remote controller  120  by communication IF  113 . 
     Microcomputer  108  stores, in memory  102 , the setting information indicating the settings on the audio signal processing in audio signal processing device  100 . Examples of the setting information stored in memory  102  include: gains which are set for the amplification processing performed by signal processing circuit  101  on the digital audio signals; selector information indicating an input terminal selected by selector  111 ; and cartridge information indicating the type of cartridge  12  in record player  10  which is connected. The cartridge information may be, for example, an identifier indicated by an input received by input IF  110  or communication IF  113  described later. Specifically, this input may be an input obtained by receiving, with input IF  110 , an operation performed by the user on input IF  110  or may be an input obtained by receiving, with communication IF  113 , an operation signal (input signal) transmitted from remote controller  120  through an operation performed by the user on remote controller  120 . The identifier is, for example, an identifier which indicates the MM type, the MC type or the like. Microcomputer  108  identifies the type of cartridge according to the identifier specified by the input received with input IF  110  or communication IF  113 , and stores, as the cartridge information, in memory  102 , the identifier indicating the type of cartridge which is identified. Alternatively, microcomputer  108  may store, as the cartridge information, in memory  102 , the identifier specified by the input received with input IF  110  or communication IF  113 . Microcomputer  108  sets the gain for the amplification processing performed by phono equalizer  103  on the analog audio signals according to the type of cartridge indicated by the identifier serving as the cartridge information stored in memory  102 . In other words, the gain set by microcomputer  108  for the amplification processing performed by phono equalizer  103  differs according to the type of cartridge indicated by the identifier serving as the cartridge information. Phono equalizer  103  uses the set gain to perform the amplification processing, and thereby can appropriately perform the amplification processing according to the type of cartridge  12 . 
     Microcomputer  108  and signal processing circuit  101  may be formed as one processing circuit such as one large scale integration (LSI) circuit or one system on a chip (SoC). When microcomputer  108  and signal processing circuit  101  are realized by one SoC, the one SoC may include another constituent element of audio signal processing device  100 . 
     Display device  109  is a device which displays information required by the user such as setting items for audio signal processing device  100  or content being reproduced. Display device  109  is formed with a liquid crystal display, an organic electro luminescence (EL) display, a fluorescent display (FL) tube or the like. Display device  109  is an example of a presenter. 
     Input IF  110  is an interface for operating audio signal processing device  100  by the user, and receives an operation from the user. Input IF  110  may be, for example, various types of switches for receiving an operation from the user. Input IF  110  may be a touch panel which is formed integrally with display device  109  and receives a touch operation from the user. 
     Communication IF  113  is an interface for communicating with an external device. Communication IF  113  may be, for example, a receiver which receives an operation signal (input signal) transmitted from remote controller  120  by an operation performed by the user. Communication IF  113  may be a wireless communicator which communicates with a portable terminal such as a smartphone or a tablet terminal. Communication IF  113  is not limited to wireless communication, and may be an interface for performing wired communication. 
     Input IF  110  and communication IF  113  are examples of a receiver which receives an input from the user. 
     Speakers  107  output sound based on the analog audio signals output from audio signal processing device  100 . 
     [1-2. Operation] 
     The operation of audio signal processing device  100  will then be described. 
     [1-2-1. Generation of Correction Parameter and Storage of Sound Setting] 
       FIG.  3    is a flowchart showing the operation of measurement processing performed by the audio signal processing device in the embodiment. 
     The user first sets, on turntable  11  in record player  10 , a test record for calculating a correction parameter (record for characteristic analysis). On the test record, the type of cartridge  12  in record player  10 , the types of transmission cables  21  and  22 , and test signals for measuring the sound characteristics of the audio signals which have been affected by the gain and the like for the amplification processing performed by signal processing circuit  101  are recorded. In other words, the test record is a phonograph record for measurement which is used for measuring changes in the sound characteristics produced in the audio signals for measurement. The changes in the sound characteristics to be measured are changes which are produced for a time after the audio signals for measurement are read by cartridge  12  in record player  10  until the audio signals for measurement reach signal processing circuit  101  in audio signal processing device  100 . The audio signals for measurement have characteristics indicated by the characteristic information which is previously stored in memory  102 . 
     Then, the user operates record player  10  to cause record player  10  to reproduce the test record. 
     Then, the user operates input IF  110  or remote controller  120  to instruct audio signal processing device  100  to measure the sound characteristics when the test record is reproduced by record player  10 . In this way, audio signal processing device  100  receives, via input IF  110  or communication IF  113 , an operation signal indicating an operation from the user (S 11 ). 
     Microcomputer  108  controls signal processing circuit  101  according to the received operation signal, and measures the sound characteristics of the audio signals of the test record received from record player  10  by input terminal  112  (S 12 ). Timing at which the performance of step S 12  is started may be before timing at which the reproduction of the test record is started by record player  10 , and the sound characteristics are preferably measured while record player  10  produces the test record. 
     Then, microcomputer  108  analyzes, based on a result of comparison between the measured sound characteristics (measurement result) and the characteristic information stored in memory  102 , changes in the sound characteristics produced by receiving influences from the entire route from cartridge  12  in record player  10  to DSP  101 . In other words, microcomputer  108  calculates differences between the measured sound characteristics and the characteristic information. Then, microcomputer  108  generates, based on the calculated differences, as the correction parameter used for the audio signal processing, a correction parameter for performing correction such that the characteristics of the audio signals which are input approach the characteristics indicated by the characteristic information (S 13 ). The audio signal processing using the correction parameter is performed on the audio signals input to signal processing circuit  101 , and thus the influences received from the entire route from cartridge  12  in record player  10  to DSP  101  can be reduced, with the result that the sound recorded on phonograph record  15  can be faithfully reproduced. The audio signal processing using the correction parameter is also said to include calibration processing for faithfully reproducing the sound recorded on the phonograph record by audio signal processing device  100 . 
     Microcomputer  108  stores, in memory  102 , the setting information and the correction parameter generated in step S 13 , in association with each other, the setting information indicating the settings on the audio signal processing in audio signal processing device  100  when the measurement is performed in step S 12  (S 14 ). The setting information stored in memory  102  in association with the correction parameter here includes, when the measurement is performed, at least one of the gain set for the amplification processing performed by signal processing circuit  101  on the digital audio signals, the selector information indicating the input terminal selected by selector  111 , and the cartridge information indicating the type of cartridge  12  in record player  10  which is connected. In the present embodiment, a set of the correction parameter and the setting information stored in memory  102  is referred to as the sound setting. As shown in  FIG.  4   , audio signal processing device  100  may store, in memory  102 , a plurality of sound settings, that is, a plurality of sets on assumption that the correction parameter and the setting information are one set. When a plurality of sound settings are stored in memory  102 , setting identifiers for identifying a plurality of sound settings are provided. The setting identifier may be the name of a sound setting input by the user or an index number. Only one sound setting may be stored in memory  102 . 
     [1-2-2. Reading Out of Sound Setting] 
       FIG.  5    is a flowchart showing the operation of sound setting application processing performed by the audio signal processing device in the embodiment. 
     The user operates input IF  110  or remote controller  120  to perform an operation of selecting and reading out the sound setting for audio signal processing device  100  stored in memory  102 . In this way, audio signal processing device  100  receives, via input IF  110  or communication IF  113 , an operation signal indicating the operation of selecting and reading out the sound setting performed by the user (S 21 ). 
     Microcomputer  108  selects, according to the received operation signal indicating the selection and reading out of the sound setting, one sound setting from one or more sound settings stored in memory  102 , and sets a correction parameter included in the selected sound setting for audio signal processing device  100  and also sets the units of audio signal processing device  100  according to the setting information (S 22 ). In other words, microcomputer  108  reads a correction parameter stored in memory  102  and the setting information stored in memory  102  in association with the correction parameter, and sets the units of audio signal processing device  100  according to the setting information read and also sets the correction parameter read for signal processing circuit  101 . In this way, when audio signal processing device  100  thereafter receives the audio signals from record player  10 , microcomputer  108  controls audio signal processing device  100  with the settings indicated by the setting information read to cause signal processing circuit  101  to perform the audio signal processing using the correction parameter read. 
     Specifically, microcomputer  108  reads one sound setting specified by the operation signal from one or more sound settings stored in memory  102 . Microcomputer  108  sets the correction parameter included in the sound setting read for signal processing circuit  101 . In this way, when audio signal processing device  100  thereafter receives the audio signals from record player  10 , signal processing circuit  101  uses the correction parameter set to perform the adjustment processing on the sound characteristics of the digital audio signals which are input. Microcomputer  108  reflects the setting information included the sound setting read on signal processing circuit  101 , phono equalizer  103 , and selector  111  in audio signal processing device  100 . 
     Specifically, microcomputer  108  sets the gain included in the setting information read for signal processing circuit  101 . In this way, when audio signal processing device  100  thereafter receives the audio signals from record player  10 , signal processing circuit  101  performs the amplification processing on the digital audio signals with the gain included in the setting information. 
     Microcomputer  108  sets, according to the type indicated by the cartridge information included in the setting information read, the gain for the amplification processing performed by phono equalizer  103  on the analog audio signals. In this way, when audio signal processing device  100  thereafter receives the audio signals from record player  10 , phono equalizer  103  is caused to perform the amplification processing with the gain corresponding to the type indicated by the cartridge information included in the setting information. 
     Microcomputer  108  causes selector  111  to select one input terminal indicated by the selector information included in the setting information read. Specifically, when the one input terminal indicated by the selector information included in the setting information read is first input terminal  112   a , microcomputer  108  causes selector  111  to select first input terminal  112   a . When the one input terminal indicated by the selector information included in the setting information read is second input terminal  112   b , microcomputer  108  causes selector  111  to select second input terminal  112   b . Hence, when audio signal processing device  100  thereafter receives the audio signals from record player  10 , signal processing circuit  101  performs, on the audio signals received using the one input terminal selected by selector  111 , the audio signal processing using the correction parameter read together with the setting information. 
     In this way, the user performs the operation of reading out the sound setting stored in memory  102  when audio signal processing device  100  performs the measurement processing, and thereby can apply the correction parameter to the digital audio signals in signal processing circuit  101  and cause audio signal processing device  100  to easily reproduce the settings on the audio signal processing in audio signal processing device  100 . 
     When the sound setting stored in memory  102  is applied to audio signal processing device  100 , microcomputer  108  may compare the gain for the amplification processing in signal processing circuit  101  and the cartridge information for cartridge  12  which are set at that time with the gain for the amplification processing in signal processing circuit  101  and the cartridge information for cartridge  12  which are included in the sound setting to be applied. Then, as a result of the comparison, when these pieces of setting information are different from each other, microcomputer  108  sets the setting information read from memory  102 , and when these pieces of setting information are the same as each other, microcomputer  108  does not need to change the setting information set at that time. 
     Microcomputer  108  may perform control to display, on display device  109 , a message indicating that all the items of the setting information set in step S 22  have been set. All the items of the setting information are information corresponding to three items of the gain set for the processing for amplifying the digital audio signals performed by signal processing circuit  101 , the selector information indicating the input terminal selected by selector  111 , and the cartridge information indicating the type of cartridge  12  in record player  10  which is connected. Microcomputer  108  may perform control to display, on display device  109 , a message indicating that only the item whose setting is changed in step S 22  has been set. When the one input terminal indicated by the selector information included in the setting information read is different from the current input terminal selected by selector  111 , microcomputer  108  may display, on display device  109 , a message indicating that the input terminal different from the one input terminal indicated by the selector information is selected by selector  111 , and may cause selector  111  to perform switching of the input terminals. 
     Audio signal processing device  100  of the present embodiment can store a plurality of sound settings. Hence, for example, when the user replaces cartridge  12  in record player  10  with another type of cartridge or when the user replaces record player  10 , the configuration of the record reproduction system differs before and after the replacement. For example, the number of combinations of N (N is a natural number) types of cartridges and M (M is a natural number) types of record players is N×M, and thus (N×M) configurations of the record reproduction system can be provided. Hence, appropriate (N×M) sound settings are respectively needed for the (N×M) configurations of the record reproduction system, and thus audio signal processing device  100  of the present embodiment can store the (N×M) sound settings in memory  102 . Therefore, the user can select and read out the sound setting corresponding to the type of cartridge  12  and the type of record player  10 . 
     Audio signal processing device  100  may have the function of being able to turn off the sound setting which is stored. Microcomputer  108  may be configured such that, when the sound setting is turned off, the stored sound setting is not applied. Here, microcomputer  108  may be configured such that one of the correction parameter and the setting information in the sound setting stored in memory  102  is not applied or may be configured such that both of them are not applied. 
     Even when the sound setting stored in memory  102  is applied to audio signal processing device  100 , audio signal processing device  100  may receive a change in the setting information. When a change in the setting information is received, the correction parameter being used is not appropriate to the setting information after the change. Hence, when a change in the setting of any one of the items included in the setting information is received, microcomputer  108  may perform control to turn off the application of the correction parameter for the audio signal processing in signal processing circuit  101 . Here, microcomputer  108  may perform control to display, on display device  109 , a message for notifying the user that the correction parameter is turned off or may control communication IF  113  to notify the message to a portable terminal of the user which is previously registered. 
     When the user operates input IF  110  or remote controller  120  to switch the setting of selector  111  (input terminal), the sound setting may be switched according to the setting of selector  111  (input terminal) selected by the user. Specifically, when an input indicating the setting of selector  111  is acquired from input IF  110  or communication IF  113 , microcomputer  108  searches for a sound setting including the same setting as the setting of selector  111  which is input among a plurality of sound settings stored in memory  102 . In other words, when a change in the setting of selector  111  (input terminal) is received, microcomputer  108  searches memory  102  for a sound setting including the selector information indicating the same input terminal as the changed input terminal. When one applicable sound setting is found in step S 22 , microcomputer  108  sets the sound setting for audio signal processing device  100 . When a plurality of applicable sound settings are found, microcomputer  108  may inquire of the user which one of the sound settings found is selected so as to cause the user to make a selection using input IF  110  or remote controller  120 . 
     [1-3. Effects and Like] 
     As described above, in the present embodiment, audio signal processing device  100  is audio signal processing device  100  that performs the audio signal processing on the audio signals reproduced in record player  10 , and includes first input terminal  112   a , memory  102 , signal processing circuit  101 , and microcomputer  108 . First input terminal  112   a  receives the audio signals from record player  10 . Memory  102  stores the correction parameter for the audio signal processing on the audio signals and the characteristic information indicating the characteristic of the audio signals for measurement. Signal processing circuit  101  performs, based on the correction parameter stored in memory  102 , the audio signal processing on the audio signals received from first input terminal  112   a . Microcomputer  108  measures, when audio signals for measurement recorded on a phonograph record for measurement are reproduced by record player  10 , the sound characteristic of the audio signals received by first input terminal  112   a  from record player  10 . Microcomputer  108  generates, based on a result of comparison between the result of the measurement and the characteristic information stored in memory  102 , the correction parameter for the audio signal processing performed in signal processing circuit  101 . Microcomputer  108  stores, in memory  102 , setting information and the correction parameter generated, in association with each other, the setting information indicating a setting on the audio signal processing in audio signal processing device  100  when the measurement is performed. 
     In audio signal processing device  100  according to the present embodiment, microcomputer  108  reads the correction parameter stored in memory  102  and the setting information stored in memory  102  in association with the correction parameter, controls audio signal processing device  100  with the setting indicated by the setting information read, and causes signal processing circuit  101  to perform the audio signal processing using the correction parameter read. 
     In this way, audio signal processing device  100  according to the present embodiment stores, in memory  102 , the setting information and the correction parameter generated, in association with each other, the setting information indicating the setting on the audio signal processing in audio signal processing device  100  when the measurement is performed. Hence, for example, when the user operates audio signal processing device  100  to select and set the correction parameter and the setting information stored in memory  102  in association with each other, the user can also automatically make the setting for audio signal processing device  100  based on the setting information in conjunction with the setting for the correction parameter. Therefore, it is possible to perform, without impairing the convenience of the user, the audio signal processing using the correction parameter obtained by performing the measurement with the setting desired by the user, with the result that desired sound quality can easily be realized. 
     Audio signal processing device  100  according the present embodiment further includes second input terminal  112   b  and selector  111 . Second input terminal  112   b  receives an input of the audio signals from record player  10 . Selector  111  selects, from first input terminal  112   a  and second input terminal  112   b , one input terminal for receiving the audio signals. The setting information includes the selector information indicating the one input terminal selected by selector  111  when the measurement is performed. Microcomputer  108  causes selector  111  to select the one input terminal indicated by the selector information included in the setting information read. Signal processing circuit  101  performs, on the audio signals received by the one input terminal selected by selector  111 , the audio signal processing using the correction parameter read together with the setting information. 
     Hence, when the input terminal selected by selector  111  is different from the input terminal indicated by the selector information included in the setting information read, the input terminal indicated by the selector information is caused to be selected by selector  111 . 
     As described above, when the setting indicated by the setting information read is different from the current setting for audio signal processing device  100 , the setting is changed to the setting indicated by the setting information, and thus it is possible to also automatically make the setting for audio signal processing device  100  based on the setting information in conjunction with the setting for the correction parameter. Therefore, the convenience of the user is enhanced. 
     In audio signal processing device  100  according to the present embodiment, the audio signal processing includes first amplification processing that is performed on digital audio signals after analog-digital conversion. The setting information includes a first gain set for the first amplification processing. Signal processing circuit  101  performs the first amplification processing with the first gain included in the setting information read. 
     Hence, when the first gain set for the first amplification processing performed by signal processing circuit  101  is different from the first gain included in the setting information read, the gain for the first amplification processing is updated to the first gain included in the setting information read. As described above, when the setting indicated by the setting information read is different from the current setting for audio signal processing device  100 , the setting is changed to the setting indicated by the setting information, and thus it is possible to also automatically make the setting for audio signal processing device  100  based on the setting information in conjunction with the setting for the correction parameter. Therefore, the convenience of the user is enhanced. 
     Audio signal processing device  100  according to the present embodiment further includes phono equalizer  103  and input IF  110  or communication IF  113 . Phono equalizer  103  performs second amplification processing on the analog audio signals received by first input terminal  112   a  or second input terminal  112   b . Input IF  110  or communication IF  113  receives an input from the user. The setting information includes the cartridge information indicated by the input received by input IF  110  or communication IF  113  and indicating the type of cartridge  12  included in record player  10 . Microcomputer  108  causes phono equalizer  103  to perform the second amplification processing with a second gain corresponding to the type of cartridge  12  indicated by the cartridge information included in the setting information read. 
     Hence, when the type of cartridge set for audio signal processing device  100  is different from the type of cartridge indicated by the cartridge information included in the setting information read, the setting for audio signal processing device  100  is updated to the type of cartridge indicated by the cartridge information. In this way, microcomputer  108  updates, according to the updated setting, the second gain for the second amplification processing performed by phono equalizer  103 . As described above, when the setting indicated by the setting information read is different from the current setting for audio signal processing device  100 , the setting is changed to the setting indicated by the setting information, and thus it is possible to also automatically make the setting for audio signal processing device  100  based on the setting information in conjunction with the setting for the correction parameter. Therefore, the convenience of the user is enhanced. 
     Audio signal processing device  100  according to the present embodiment further includes display device  109  that displays a message. When the one input terminal indicated by the selector information included in the setting information read is different from the input terminal selected by selector  111 , microcomputer  108  displays, on display device  109 , a message indicating that the input terminal different from the one input terminal is selected by selector  111 . Hence, it is possible to provide a notification to the user that the input terminal different from the one input terminal is selected by selector  111 . 
     Other Embodiments 
     The embodiment has been described above as an example of techniques disclosed in the present application. However, the techniques disclosed in the present disclosure are not limited to the embodiment, and can be applied to embodiments obtained by performing changes, replacements, additions, omissions, and the like. Embodiments can be newly provided by combining the constituent elements described in Embodiment 1 above. 
     For example, although in the above embodiment, each of signal processing circuit  101  and microcomputer  108  has its own roles, a part or the whole of the processing to be performed by signal processing circuit  101  may be performed by microcomputer  108  or a part or the whole of the processing to be performed by microcomputer  108  may be performed by signal processing circuit  101 . 
     For example, although in the above embodiment, the example is described where the test record is used for the analysis of the sound characteristics, the present disclosure is not limited to this example. For example, the test signals may be input from a portable terminal device different from record player  10 . In other words, the portable terminal device inputs the test signals to input terminal  112  in audio signal processing device  100 . 
     For example, although in the above embodiment, the example is described where, as the setting items automatically set when the correction parameter is applied, the gain for signal processing circuit  101 , the type of cartridge  12 , and the input terminal selected by selector  111  are mentioned as examples, settings other than those described above may be used as long as they are settings on sound characteristics. 
     For example, although in the above embodiment, the example is described where signal processing circuit  101  performs the amplification with the gain set for the digital audio signals, the present disclosure is not limited to this example. For example, the amplification processing may be performed by another constituent element such as phono equalizer  103 . In such a case, microcomputer  108  sets a gain for the constituent element described above, and the constituent element performs the amplification processing with the set gain. 
     For example, although in the above embodiment, the example is described where microcomputer  108  corrects, based on the information of the type of cartridge  12  which is set, the gain for the amplification processing in phono equalizer  103 , the present disclosure is not limited to this example. Microcomputer  108  may correct or set, based on the information of the type of cartridge  12 , a parameter for another constituent element of audio signal processing device  100 . For example, microcomputer  108  may correct, based on the information of the type of cartridge  12 , the gain for the amplification processing on the digital audio signals in signal processing circuit  101  and the parameter for the audio signal processing in signal processing circuit  101 . As described above, microcomputer  108  corrects or sets parameters for the units, and thus audio signal processing device  100  can appropriately perform processing on the audio signals according to the type of cartridge  12 . 
     For example, in the above embodiment, when the one input terminal indicated by the selector information included in the setting information read is different from the current input terminal selected by selector  111 , microcomputer  108  displays, on display device  109 , the message indicating that the input terminal different from the one input terminal indicated by the selector information is selected by selector  111 , and then causes selector  111  to perform switching of the input terminals. However, the present disclosure is not limited to this configuration. In this case, it is not necessary to cause selector  111  to perform switching of the input terminals. Moreover, this message may further include a message for prompting the user to provide, from input IF  110  or remote controller  120 , an input for switching the setting of selector  111  to the one input terminal indicated by the selector information. Hence, it is possible to notify the user that the input terminal different from the one input terminal is selected by the selector. In this way, it is possible to avoid an event where as a result of selector  111  automatically switching input terminal  112 , unintended input terminal  112  is selected to output unintended sound or input terminal  112  to which nothing is connected is selected such that sound is not output at all. 
     For example, although in the above embodiment, audio signal processing device  100  can store a plurality of correction parameters and can turn off the correction parameter, audio signal processing device  100  may be configured to be able to store only one correction parameter. Audio signal processing device  100  does not need to have the function of turning off the correction parameter. 
     For example, in the above embodiment, when the setting information in audio signal processing device  100  is changed by an operation performed by the user while the correction parameter is being applied, the message for providing a notification that the correction parameter is not appropriate to the setting after the change is displayed on display device  109 , and the application of the correction parameter is turned off. However, the application of the correction parameter may be continued by displaying, on display device  109 , a message for providing a notification that the setting cannot be changed. 
     For example, although in the above embodiment, microcomputer  108  displays a message on display device  109  when a notification is provided to the user, the present disclosure is not limited to this configuration. Microcomputer  108  may control communication IF  113  to notify the message to a portable terminal of the user which is previously registered. In other words, display device  109  and communication IF  113  are examples of the presenter which presents a message. 
     For example, in the above embodiment, the state of the application of the correction parameter is stored for each of the input terminals which can be selected by selector  111 , and when switching is performed by selector  111 , the correction parameter is automatically switched to the stored correction parameter. However, the switching does not need to be performed. 
     For example, in the above embodiment,  FIG.  1    shows the configuration where an unbalanced signal (RCA) and a balanced signal (XLR) are output from record player  10  and one of them is selected by selector  111  in audio signal processing device  100 . Although in the configuration, selector  111  makes a selection from two PHONO inputs, the configuration can be applied to many variations such as a variation where both RCA and XLR are connected from one record player  10  and a variation where RCA and XLR are respectively connected from two record players, and the connection method is not limited. 
     The above embodiments are intended to describe examples of the techniques disclosed in the present disclosure, and thus various changes, replacements, additions, omissions, and the like can be performed in the scope of claims or a scope equivalent thereto. 
     INDUSTRIAL APPLICABILITY 
     The present disclosure can be applied to an audio signal processing device which can perform audio signal processing corresponding to the characteristics of a record reproduction system and the like.