Equalizer, equalizer gain value calibration method, chip, and calibration device

Abstract

The present application discloses an equalizer, a calibration method for the gain value of the equalizer, a chip, and a calibration device. The equalizer includes N filters connected in series, and the bandwidth value and the center frequency value of each filter are fixed. The calibration method for the gain value of the equalizer includes: determining the initial frequency response curve of the filter based on the bandwidth value, the center frequency value, and the unit gain value corresponding to each filter; constructing a gain matrix based on the initial gain value corresponding to the center frequency on the initial frequency response curve of each filter, and the dimension of the gain matrix is ​​N; using the gain matrix to remove the gain values ​​generated by other filters contained in the initial gain value of each filter, as the new gain value displayed on the calibrated frequency response curve, so that the gain adjustment value set by the user matches the new gain value, so that the actual frequency response curve of the calibrated equalizer can be basically consistent with the gain curve determined based on the gain adjustment value, thereby enhancing the gain effect of the equalizer.

Description

Technical Field

[0001] The present application relates to equalizer debugging technology, and in particular to an equalizer, a calibration method for an equalizer gain value, a chip, and a calibration device. Background Art

[0002] The equalizer is a technology that adjusts the frequency response of each frequency band in the audio signal. It can adjust the gain of the low-frequency, medium-frequency and high-frequency components of the audio signal, thereby changing the timbre and sound quality of the audio. The equalizer design is generally implemented through the combination of multiple filters. The combination of filters can be in series or in parallel. Taking the series connection as an example, when the filters in the equalizer are combined in series, the audio input data to be processed by each filter is the audio data output after processing by the previous filter of the filter.

[0003] In the related art, when designing an equalizer, the number of filters and the center frequency of each filter are first determined. When the filters are combined in series, the center frequencies of the filters may be close to each other, and the filters in series will affect each other, causing the gain of the filter corresponding to a certain center frequency to deviate from the gain set by the user under the influence of the surrounding filters, resulting in a poor gain effect. Summary of the invention

[0004] In view of the above technical problems, the present application provides an equalizer, a calibration method for an equalizer gain value, a chip, and a calibration device. The technical solution is as follows:

[0005] According to a first aspect of the present application, an equalizer is provided, the equalizer comprising N filters connected in series and a processing chip, wherein the bandwidth value and the center frequency value of each filter are fixed;

[0006] The processing chip is used to determine the initial frequency response curve of the filter based on the bandwidth value, center frequency value and unit gain value corresponding to each filter; construct a gain matrix based on the initial gain value corresponding to the center frequency on the initial frequency response curve of each filter, and the dimension of the gain matrix is ​​N; use the gain matrix to remove the gain values ​​generated by other filters contained in the initial gain value of each filter as the new gain value displayed on the calibrated frequency response curve, so that the gain debugging value set by the user matches the new gain value.

[0007] According to a second aspect of the present application, a method for calibrating an equalizer gain value is provided, wherein the equalizer includes N filters connected in series, and the bandwidth value and center frequency value of each filter are fixed, and the method includes:

[0008] Determine an initial frequency response curve of the filter based on a bandwidth value, a center frequency value, and a unit gain value corresponding to each filter;

[0009] Constructing a gain matrix based on initial gain values ​​corresponding to the center frequency on the initial frequency response curve of each filter, wherein the dimension of the gain matrix is ​​N;

[0010] The gain matrix is ​​used to remove the gain values ​​generated by other filters contained in the initial gain value of each filter, and the new gain value is displayed on the calibrated frequency response curve, so that the gain adjustment value set by the user matches the new gain value.

[0011] According to a third aspect of the present application, a chip is provided for calibrating an equalizer, wherein the equalizer comprises N filters connected in series, each filter having a fixed bandwidth value and a fixed center frequency value, and the chip is used to execute the equalizer gain value calibration method as described in the second aspect.

[0012] According to a fourth aspect of the present application, a calibration device is provided, which is connected to an equalizer. The calibration device is equipped with a chip as described in the third aspect. The equalizer includes N filters connected in series, and the bandwidth value and center frequency value of each filter are fixed.

[0013] The present application provides a gain calibration scheme for an equalizer that is composed of N filters connected in series, and the bandwidth value and center frequency value of each filter are fixed. For the gains generated by other filters included in the gain of one filter among the N filters connected in series, the gain matrix and the unit gain value can be used to reversely deduce the gain influence of other filters on each filter, thereby subtracting the gain generated by other filters to obtain the calibrated gain value, and each filter uses the calibrated filter gain value for series calculation to obtain a calibrated frequency response curve, which can eliminate the mutual gain influence of each filter in the series filter, so that the gain corresponding to the center frequency of each filter in the calibrated equalizer is close to the gain adjustment value set by the user, so that the actual frequency response curve of the calibrated equalizer is basically consistent with the gain curve determined based on the gain adjustment value, thereby enhancing the gain effect of the equalizer.

[0014] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0016] Figure 1 is a schematic diagram of an equalizer structure of the related technology;

[0017] Figure 2 It is a flowchart of a method for calibrating an equalizer gain value of the present application;

[0018] Figure 3 is a schematic diagram of the structure of an equalizer according to an embodiment of the present application;

[0019] Figure 4 is a schematic structural diagram of a calibration device according to an embodiment of the present application;

[0020] Figure 5 is a schematic diagram of a frequency response curve of a related art;

[0021] Figure 6 It is a schematic diagram of a calibrated frequency response curve of an embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described in detail below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field should fall within the scope of protection of this application.

[0023] An equalizer is a technology that adjusts the frequency response of each frequency band in an audio signal. It can adjust the gain of the low-frequency, medium-frequency and high-frequency components of the audio signal, thereby changing the timbre and sound quality of the audio. An equalizer can divide the audio spectrum into multiple frequency ranges, such as low frequency, medium frequency and high frequency, and control the audio signals in the corresponding ranges respectively. An equalizer has a gain control in each frequency range. The gain control is used to increase or decrease the strength of the audio signal in a certain frequency range. The strength is generally measured in dB. An equalizer can control the width of each frequency range through bandwidth. A broadband equalizer has a wider adjustment range, and a narrowband equalizer can achieve more precise adjustments. Equalizers can also be divided into many types, such as graphic equalizers (GEQ), parametric equalizers (PEQ), etc. Different types of equalizers can be suitable for different application scenarios. The working principle of the equalizer can be: the audio signal input to the equalizer is divided into different frequency ranges through different types of filters such as bandpass, low-pass and high-pass filters, and the signal in the frequency range is amplified or attenuated according to the gain control on each frequency range, and then the frequency signals in each frequency range are remixed to obtain the output audio signal. By adjusting the signal ratio of different frequency ranges, the tone, timbre and sound quality of the audio can be changed.

[0024] Equalizer design is generally achieved through a combination of multiple filters. Filters can be used for audio signal processing and can extract or shield certain frequency components in audio signals. According to the frequency range processed by the filter, filters can be divided into four types: low-pass filter, high-pass filter, band-pass filter and band-stop filter. Among them, the low-pass filter can allow audio signals below the cutoff frequency to pass through, and shield signals above the cutoff frequency, which is used to obtain low-frequency signals; the high-pass filter can allow signals above the cutoff frequency to pass through, and shield signals below the cutoff frequency, which is used to obtain high-frequency signals; the band-pass filter can allow signals within a certain center frequency range to pass through, and shield signals outside this range, which is used to obtain signals within a certain frequency range; the band-stop filter can shield signals within a certain center frequency range, and allow signals outside this range to pass through, which is used to reduce signals within a certain frequency range. The bandwidth of the filter can characterize the frequency range through which the filter passes, which indicates the width of the filter. The wider the bandwidth, the more frequency components the filter can pass.

[0025] The filters can be connected in series or in parallel. Figure 1 , taking series connection as an example, when the filters in the equalizer are combined in series, the audio input data to be processed by each filter is the audio data output after processing by the previous filter of the filter. When the filters in the equalizer are combined in parallel, each filter processes the audio input data at the same time, and then the processing results of each filter are combined as the equalizer output.

[0026] The frequency response curve can represent the response curve of the equalizer to audio input signals of different frequencies. It can reflect the amplification and attenuation degree of each frequency component and is an important indicator of the equalizer gain effect. The X-axis of the frequency response curve can represent the frequency of the audio input signal in Hz, and the Y-axis can represent the amplitude of the audio signal in dB. The shape of the curve can represent the response of the equalizer filter to audio signals of different frequencies, which can provide a basis for the analysis, design and calibration of the equalizer.

[0027] In the related art, when designing an equalizer, the number of filters and the center frequency of each filter are first determined. When the filters are combined in series, the center frequencies of the filters may be close to each other, and the filters in series will affect each other, causing the gain of the filter corresponding to a certain center frequency to deviate from the gain set by the user under the influence of the surrounding filters, resulting in a poor gain effect. For example, the actual frequency response curve of the equalizer is quite different from the frequency response curve determined based on the gain set by the user. For example, a peak filter with a gain value of 5.0dB is designed at the center frequency of 31Hz, and a peak filter with a gain value of 5.0dB is also designed at the center frequency of 63Hz. Then, the gain values ​​of the two peak filters in series will increase each other, and the final result of the series connection is that the actual gain values ​​at 31Hz and 63Hz are both much larger than 5.0dB.

[0028] In view of the above problems, the present application provides a method for calibrating the gain value of an equalizer, wherein the equalizer includes N filters connected in series, and the bandwidth value and center frequency value of each filter are fixed, so that the gain corresponding to the center frequency of each filter in the calibrated equalizer is close to the gain adjustment value set by the user, so that the actual frequency response curve of the calibrated equalizer is basically consistent with the gain curve determined based on the gain adjustment value, thereby enhancing the gain effect of the equalizer, such as Figure 2 As shown, the method comprises the following steps:

[0029] S201, determining an initial frequency response curve of the filter based on a bandwidth value, a center frequency value, and a unit gain value corresponding to each filter;

[0030] In this embodiment, the bandwidth value (quality factor, Q) and center frequency value (center frequency, fc) of each filter of the equalizer are fixed, that is, when the equalizer gain value is calibrated in this embodiment, the bandwidth value and center frequency value of each filter are determined and cannot be changed, while the gain value (gain) of each filter can be changed, for example, the gain value of the filter can be preset, or the gain adjustment value of the filter can be set.

[0031] As an example, the above-mentioned equalizer can be a graphic equalizer. Since the bandwidth value and center frequency value of each filter in the graphic equalizer are fixed, when adjusting the graphic equalizer, it is only necessary to adjust the gain value of each filter of the graphic equalizer. The graphic equalizer is different from the parametric equalizer. Each bandwidth value, center frequency value and gain value of the parametric equalizer can be adjusted. Therefore, when the equalizer is selected as a parametric equalizer, its gain is difficult to represent its frequency response curve, and when the equalizer is selected as a graphic equalizer, the gain of the graphic equalizer can represent its frequency response curve. Therefore, selecting a graphic equalizer can make it easier to adjust the parameters of the equalizer, so that the adjustment effect and accuracy are better.

[0032] It is worth noting that the above selection of the equalizer as a graphic equalizer is only an exemplary display. In practical applications, it is not excluded that the bandwidth value and center frequency value of each filter are other types of equalizers that are determined, and there is no specific limitation on the type of equalizer.

[0033] As an example, taking N=10, the above-mentioned equalizer can be divided into 10 segments. When divided into 10 segments, the center frequency values ​​of 10 filters can be determined as 31Hz, 63Hz, 125Hz, 250Hz, 500Hz, 1000Hz, 2000Hz, 4000Hz, 8000Hz, and 16000Hz respectively according to an octave. If the equalizer is divided into 20 segments, the center frequency values ​​of 20 filters can be determined in half an octave. If it is divided into 30 segments, the center frequency values ​​of 30 filters can be determined in one-third an octave.

[0034] The bandwidth value of the filter can affect the range of the filter in the frequency domain. In order to ensure that the filter is adjusted finely enough to ensure the gain adjustment effect, as an example, the bandwidth value of each filter can be greater than or equal to 0.7.

[0035] It is worth noting that the above-mentioned method for determining the center frequency value and bandwidth value of the filter is only an exemplary display. In practical applications, other determination methods are not excluded and are not specifically limited to this.

[0036] In order to facilitate subsequent parameter calculations and improve calculation efficiency, as an example, the unit gain value of each filter can be preset to be 1.0 dB. It is worth noting that the above-mentioned method of taking the unit gain value is only an exemplary display. In practical applications, other value taking methods are not excluded. For example, the unit gain value of each filter is taken as 2.0 dB or 3.0 dB or other values, and there is no specific limitation on the unit gain value.

[0037] The center frequency value, bandwidth value and unit gain value of the filter determined above can be used to calculate the filter parameters according to different filter types. As an example, the filter can be selected as an IIR filter. The IIR filter has a simple structure and a small number of parameters. It is convenient to calculate the parameters and is also more conducive to adjusting its parameters. It is worth noting that the above selection of the filter type is only an exemplary display. In practical applications, it is not excluded to select other types, such as FIR filters, and there is no specific limitation on this.

[0038] As an example, the parameters of the filter may include six parameters: b0, b1, b2, a0, a1, and a2. The parameters may be calculated from different types of filters and the center frequency value, bandwidth value, and unit gain value determined by the filters. For each sample data input to the filter, the filtering process may be as shown in the following formula:

[0039] y = b0*(a0*x + a1*x1 + a2*x2 – b1*y1 – b2*y2) (1)

[0040] Among them, x represents the current input sampling point data, x1 can represent the previous input sampling point data of x, x2 is the two previous input sampling point data of x, y is the current output data, y1 is the previous output data of y, and y2 is the two previous output data of y. Each sampling point data input corresponds to a data output.

[0041] It is worth noting that the above-mentioned filter parameters and filtering process are only exemplary. In practical applications, other parameters and other processing processes are not excluded and are not specifically limited.

[0042] As an example, the initial frequency response curve of each filter may be determined according to the filter parameters calculated above.

[0043] S202, constructing a gain matrix based on initial gain values ​​corresponding to the center frequency on the initial frequency response curve of each filter, wherein the dimension of the gain matrix is ​​N;

[0044] The gain matrix can be constructed in many ways. As an example, one way to construct the gain matrix can include: taking the initial gain value generated by each filter at a certain center frequency as the row of the matrix. For example, the initial gain values ​​generated by N filters at the center frequency f1 are g11, g12, g13...g1N, then the N initial gain values ​​corresponding to the center frequency f1 are taken as a row of the gain matrix. Similarly, the N initial gain values ​​corresponding to the center frequencies f2, f3...fN can be obtained. The N initial gain values ​​corresponding to each center frequency are taken as a row of the gain matrix to obtain an N*N gain matrix. The gain matrix can characterize the mutual gain influence between the N filters. Taking N=10 as an example, the gain matrix can be 10*10.

[0045] S203, using the gain matrix to remove the gain values ​​generated by other filters contained in the initial gain value of each filter, and using the new gain value displayed on the calibrated frequency response curve, so that the gain adjustment value set by the user matches the new gain value.

[0046] The gain matrix can be used in a variety of ways to remove the gain values ​​generated by other filters contained in the initial gain value of each filter. As an example, one way to use the gain matrix to remove the gain values ​​generated by other filters contained in the initial gain value of each filter may include: determining the inverse matrix of the gain matrix, and using the inverse matrix, the bandwidth value and center frequency value corresponding to each filter, and the gain adjustment value set by the user to remove the gain values ​​generated by other filters contained in the initial gain value of each filter. By inverting the gain value, the gain of other filters at each frequency point can be subtracted for each filter.

[0047] As an example, the gain adjustment value set by the user can be converted into an intermediate gain value through the above inverse matrix, and then the new gain value displayed on the calibrated frequency response curve can be obtained from the intermediate gain value. There are many conversion methods, one of which is shown as follows:

[0048] g_hid = g_custom*GMi (2)

[0049] Among them, GMi is the above inverse matrix, g_custom is the vector obtained by the gain adjustment value set by the above user, and g_hid is the calculation result, that is, the vector of the intermediate gain value. Taking N=10 as an example, g_custom and g_hid can both represent vectors of 10 values.

[0050] The specific application of the above embodiment is illustrated below by way of example:

[0051] Taking N=2 as an example, the two filters F1 and filter F2 connected in series can correspond to the center frequencies f1 and f2 respectively. The unit gain values ​​of the two filters are set to 1.0dB. The initial gain values ​​generated by F1 at f1 and f2 are g11 and g22 respectively; the initial gain values ​​generated by F2 at f1 and f2 are g21 and g22 respectively. Based on these initial gain values, the gain matrix GM=[g11, g12; g21, g22] is constructed. The vector g_custom=[gc1, gc2] obtained based on the gain debugging value set by the user, the calculation result is the vector g_hid=[gc1*(1-g11-g12), gc2*(1-g21-g22)] of the intermediate gain value.

[0052] The unit gain values ​​are all set to 1.0dB, which can facilitate the calculation of the gain matrix GM. However, the unit gain values ​​are not limited to 1.0dB, and can also be other values. For example, when the unit gain values ​​are all set to 1.0dB, assuming that the initial gain value generated by each filter at f1 is 0.5dB, it can be roughly estimated that when the unit gain values ​​are all set to 2.0dB, the initial gain value generated by each filter at f1 is 2*0.5=1dB. It is worth noting that the above-mentioned method of converting the gain adjustment value set by the user into the intermediate gain value is only an exemplary display. In practical applications, other conversion methods are not excluded, and there is no specific limitation on this.

[0053] As an example, the filter gain intermediate value obtained in the above steps, the bandwidth value corresponding to each filter and the center frequency value can be used to recalculate the parameters b and a of each filter (for example, b0, b1, b2, a0, a1, a2 mentioned above), so as to obtain the calibrated frequency response curve.

[0054] The gain adjustment value set by the user is variable. To ensure that the gain adjustment value set by the user does not cause extreme effects, as an example, the range of the gain adjustment value may be -48dB to 48dB. There is no specific limitation on the range of the gain adjustment value.

[0055] In the related art, when filters are connected in series, the parameters b and a of each filter are superimposed together to form an SOS matrix, and the complexity of the filter becomes higher. Compared with a high-order filter, especially when the filter is an IIR filter, the stability of the high-order filter is poor. If the previous filter has a large gain for the audio data, the subsequent filter may cause data overflow (overexposure) during the filtering process, resulting in popping sounds. For example, the gain of the first filter is gain = 5.0, and the gain of the second filter is gain = 5.0. After the audio data passes through these two filters, the energy will increase, and it will become larger and larger when it reaches the subsequent filters, which may exceed the dynamic range of the data, resulting in clipping or even popping sounds.

[0056] In response to the above problem, the new gain value can be determined in a variety of ways. In order to limit the gain range of the filter and avoid the problem of popping, as an example, one of the determination methods may include: the new gain value is determined based on the weight corresponding to each filter, and the weight is determined based on the maximum gain value among the N filters.

[0057] As an example, the weights may be determined according to the inverse of the maximum gain values ​​among the N filters.

[0058] It is worth noting that the above-mentioned method for determining the new gain value is only an exemplary display. In practical applications, other determination methods are not excluded and are not specifically limited to this.

[0059] The technical solution provided by the present application provides a gain calibration solution for an equalizer composed of N filters connected in series, wherein the bandwidth value and center frequency value of each filter are fixed. For the gains generated by other filters included in the gain of one filter among the N filters connected in series, the gain matrix and the unit gain value can be used to reversely deduce the gain influence of other filters on each filter, thereby subtracting the gain generated by other filters to obtain the calibrated gain value, and each filter uses the calibrated filter gain value for series calculation to obtain a calibrated frequency response curve, which can eliminate the mutual gain influence of each filter in the series filter, so that the gain corresponding to the center frequency of each filter in the calibrated equalizer is close to the gain adjustment value set by the user, so that the actual frequency response curve of the calibrated equalizer is basically consistent with the gain curve determined based on the gain adjustment value, thereby enhancing the gain effect of the equalizer.

[0060] Corresponding to the above method embodiment, as a specific application, the above embodiment can be applied to an equalizer for implementation. Therefore, the present application also provides an equalizer, see Figure 3 As shown, the equalizer 301 may include: N filters 303 and a processing chip 302 connected in series, and the bandwidth value and center frequency value of each filter 303 are fixed;

[0061] The processing chip 302 determines the initial frequency response curve of the filter 301 based on the bandwidth value, center frequency value and unit gain value corresponding to each filter 301; constructs a gain matrix based on the initial gain value corresponding to the center frequency on the initial frequency response curve of each filter 301, and the dimension of the gain matrix is ​​N; uses the gain matrix to remove the gain values ​​generated by other filters 301 contained in the initial gain value of each filter 301, as the new gain value displayed on the calibrated frequency response curve, so that the gain debugging value set by the user matches the new gain value.

[0062] As an example, the processing chip 302 can determine the inverse matrix of the gain matrix, and use the inverse matrix, the bandwidth value, the center frequency value and the gain adjustment value to remove the gain values ​​generated by other filters 301 included in the initial gain value of each filter 301.

[0063] Similar to the calibration method of the equalizer gain value above, the new gain value processed by the processing chip 302 can be determined according to the weight corresponding to each filter 301, and the weight can be determined according to the maximum gain value of the N filters 301. As an example, the weight is determined according to the inverse of the maximum gain value.

[0064] It is worth pointing out that each embodiment of the above-mentioned method for calibrating the gain value of the equalizer can be applied to the process of the processing chip 302 calibrating the frequency response curve and generating a new gain value.

[0065] The present application also provides a chip, which is suitable for calibrating any equalizer to which the calibration method for equalizer gain value described above in the present application is applicable, and the chip is used to execute the calibration method for equalizer gain value described in any embodiment above. The present application does not limit the specific device into which the chip is integrated, for example, the chip can be used as Figure 3 The processing chip 302 may be used for the purpose, and integration into other devices is not excluded.

[0066] The present application also provides a calibration device, Figure 3 Different from the embodiments provided, the process of calibrating the equalizer gain value is implemented on the calibration device. Figure 4 As shown, the calibration device 401 is connected to an equalizer 403. The calibration device 401 is equipped with a chip 402 to implement the functions described in the above embodiments. The equalizer 403 includes N filters 404 connected in series, and the bandwidth value and center frequency value of each filter 404 are fixed.

[0067] See also Figure 5 , Figure 5 The figure shows a frequency response curve diagram of the related technology. Figure 5 Taking several peak filters in series with a gain adjustment value of gain=5.0 set by the user as an example, when the equalizer gain value calibration described in the embodiment of the present application is not performed, the series-connected filters raise each other's gain so that the gain is raised to gain>6.0 at the center frequency, which is quite different from the gain adjustment value gain=5.0 set by the user.

[0068] and Figure 5 For comparison, see Figure 6 , Figure 6 is a schematic diagram of a calibrated frequency response curve of an embodiment of the present application, Figure 6 Taking several peak filters in series with a gain adjustment value gain=5.0 set by the user as an example, when the equalizer gain value calibration described in the embodiment of the present application is performed, in the frequency response curve diagram after calibration, the gain at the center frequency of the several peak filters is the new gain value gain=5.0, and the new gain value matches the gain adjustment value set by the user, so that the gain of the graphical equalizer can truly achieve the "graphic" effect, that is, the gain curve determined based on the gain adjustment value is basically consistent with the actual frequency response curve, which greatly reduces the mutual gain influence of the filters, thereby enhancing the equalizer gain effect.

[0069] The above is only a specific implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. An equalizer, characterized in that: The equalizer includes N filters and processing chips connected in series, and the bandwidth value and center frequency value of each filter are fixed; The processing chip is used to determine the initial frequency response curve of the filter based on the bandwidth value, center frequency value and unit gain value corresponding to each filter; construct a gain matrix based on the initial gain value corresponding to the center frequency on the initial frequency response curve of each filter, and the dimension of the gain matrix is ​​N; Determine an inverse matrix of the gain matrix, and convert the gain adjustment value set by the user into an intermediate gain value based on the inverse matrix; Based on the bandwidth value, the center frequency value and the intermediate gain value, a calibrated frequency response curve of the filter and a new gain value displayed on the calibrated frequency response curve are determined so that the gain adjustment value set by the user matches the new gain value.

2. The equalizer according to claim 1, characterized in that The new gain value is determined according to the weight corresponding to each filter, and the weight is determined according to the maximum gain value among the N filters.

3. The equalizer according to claim 2, characterized in that The weight is determined according to the inverse of the maximum gain value.

4. A method for calibrating the gain value of an equalizer, wherein the equalizer comprises N filters connected in series, each filter having a fixed bandwidth value and a fixed center frequency value, characterized in that: The method comprises: Determine an initial frequency response curve of the filter based on a bandwidth value, a center frequency value, and a unit gain value corresponding to each filter; Constructing a gain matrix based on initial gain values ​​corresponding to the center frequency on the initial frequency response curve of each filter, wherein the dimension of the gain matrix is ​​N; Determine an inverse matrix of the gain matrix, and convert the gain adjustment value set by the user into an intermediate gain value based on the inverse matrix; Based on the bandwidth value, the center frequency value and the intermediate gain value, a calibrated frequency response curve of the filter and a new gain value displayed on the calibrated frequency response curve are determined to match the gain adjustment value with the new gain value.

5. The method according to claim 4, characterized in that The new gain value is determined according to the weight corresponding to each filter, and the weight is determined according to the maximum gain value among the N filters.

6. The method according to claim 5, characterized in that The weight is determined according to the inverse of the maximum gain value.

7. A chip for calibrating an equalizer, the equalizer comprising N filters connected in series, each filter having a fixed bandwidth value and a fixed center frequency value, characterized in that: The chip is used to execute the equalizer gain value calibration method according to any one of claims 4 to 6.

8. A calibration device, connected to an equalizer, characterized in that: The calibration device is installed with the chip of claim 7, and the equalizer includes N filters connected in series, and the bandwidth value and center frequency value of each filter are fixed.

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