CN115623386A - Loudspeaker displacement protection device and method and electronic equipment - Google Patents

Abstract

A loudspeaker displacement protection device, method and electronic device, the loudspeaker displacement protection device includes: the frequency division module comprises at least one first frequency division unit and is used for dividing the frequency of the input audio signal and outputting a plurality of frequency band signals with consistent phases; the displacement module is connected with the output end of the frequency division module and used for outputting corresponding displacement data according to the frequency band signal; and the output module is connected with the output ends of the frequency division module and the displacement module and used for performing gain control on the corresponding frequency band signals according to each displacement data and outputting the frequency band signals subjected to gain control to the driving end of the loudspeaker after the frequency band signals subjected to gain control are superposed. The frequency division module is used for dividing the frequency of the input audio signal and outputting a plurality of frequency band signals with consistent phases, and because each frequency band signal has no phase difference, the accuracy of loudspeaker displacement protection is improved.

Description

Loudspeaker displacement protection device and method and electronic equipment

Technical Field

The application relates to the technical field of signal processing, in particular to a loudspeaker displacement protection device and method and electronic equipment.

Background

The loudspeaker is widely applied to various audio equipment and provides driving voltage through the driving circuit. The displacement that the vibrating diaphragm of speaker produced when the motion is relevant with driving voltage, in order to guarantee that the vibrating diaphragm of speaker can not exceed maximum displacement, avoids the speaker to damage, needs carry out the displacement protection.

In the multi-band displacement protection technology used in the prior art, phase differences exist between signals of each frequency band, for example, two signals with the phase difference of 90 degrees and the peak value of 0.1V (volt) are superimposed, and the obtained summation signal is not a 100Hz signal with the peak value of 0.2V. In the prior art, when the predicted displacement of each frequency band generates the gain of each frequency band, the influence of phase difference between signals of each frequency band is not considered, so that the generated gain excessively suppresses or insufficiently suppresses the signals of the frequency bands, the displacement protection accuracy of the loudspeaker is low, and the final loudness of the loudspeaker is influenced.

Disclosure of Invention

In view of this, the present application provides a speaker displacement protection apparatus, a speaker displacement protection method, and an electronic device, so as to solve the problems that the existing speaker displacement protection has low accuracy and affects the sound loudness of a speaker.

The application provides a speaker displacement protection device includes: the frequency division module comprises at least one first frequency division unit and is used for dividing the frequency of the input audio signal and outputting a plurality of frequency band signals with consistent phases; the displacement module is connected with the output end of the frequency division module and used for outputting corresponding displacement data according to the frequency band signal; and the output module is connected with the output ends of the frequency division module and the displacement module and used for carrying out gain control on the corresponding frequency band signals according to the displacement data and outputting the frequency band signals subjected to gain control to the driving end of the loudspeaker after being superposed.

According to the scheme, the frequency division module is used for dividing the input audio signals and outputting a plurality of frequency band signals with consistent phases, and because no phase difference exists between every two frequency band signals, the influence caused by the phase difference is eliminated when the frequency band signals are superposed, so that the accuracy of loudspeaker displacement protection is improved, and the damage caused when the loudspeaker diaphragm displacement exceeds the maximum displacement threshold value is avoided.

Preferably, the output module includes: the displacement gain control unit is connected to the output end of the displacement module and used for outputting the displacement gain corresponding to each frequency band signal according to the comparison result of the sum of the displacement data of each data point and a preset threshold; and the output unit is connected with the displacement gain control unit and the output end of the frequency division module, and is used for performing gain control on the frequency band signals according to the corresponding displacement gains and outputting the frequency band signals subjected to gain control to the driving end of the loudspeaker after the frequency band signals are superposed.

The displacement module can output displacement data in real time according to each frequency band signal, because the frequency band data are a plurality of data point signals within a period of time, the corresponding displacement data are also a plurality of data points, and because the displacement data corresponding to each frequency band signal output by the displacement module also have phase difference, errors can be brought by directly taking the peak value of each displacement data to calculate the displacement gain of each frequency band signal in a superposition manner. In order to avoid the situation that the displacement gain calculation result has errors due to phase differences of displacement data, the scheme outputs the displacement gain corresponding to each frequency band signal according to the comparison result of the sum of the displacement data of each data point and a preset threshold value through a displacement gain control unit, and performs corresponding displacement gain adjustment on each displacement data in the multi-frequency band signal to ensure that the displacement gain of the driving signal after all the frequency band signals are superposed is in a preset range, so that the situation that the displacement gain calculation result has errors due to the phase differences of the displacement data is eliminated, refined displacement control is realized, suppression on the performance of the loudspeaker is avoided, and the loudness of the final sound signal of the loudspeaker is not influenced.

Preferably, the frequency dividing module further includes: the second frequency dividing unit is used for performing prescaled frequency division on the input audio signal according to a prescaled frequency division threshold value and outputting a first prescaled frequency division signal and a second prescaled frequency division signal which are consistent in phase; the first frequency dividing unit is connected to the first output end of the second frequency dividing unit and used for performing secondary frequency division on the first pre-frequency dividing signal and outputting a plurality of frequency band signals with consistent phases; and the output module is also used for superposing the frequency band signal after gain control and the second pre-frequency division signal and outputting the superposed frequency band signal to the driving end of the loudspeaker.

According to the scheme, the second frequency dividing unit is used for pre-dividing the input audio signal according to the pre-dividing threshold value, separating out the first pre-divided signal with large influence on displacement, and re-dividing the first divided signal, so that the phase difference between the channel signals is eliminated, the displacement protection accuracy is improved, and meanwhile, the signal processing efficiency is improved.

Preferably, the speaker displacement protection device further comprises: the voltage gain control module is connected to the output end of the frequency division module and used for outputting corresponding voltage gain according to the frequency band signal; the output module further comprises a comparison unit, the comparison unit is connected to the output ends of the voltage gain control module and the displacement gain control unit and used for comparing the displacement gain with the voltage gain and outputting a comparison gain, and the output unit is further used for carrying out gain control on corresponding frequency band signals according to the comparison gain.

According to the scheme, the voltage gain control module is used for carrying out gain control on each frequency band signal according to the corresponding voltage gain, and the displacement gain and the voltage gain are compared to carry out gain control on the corresponding frequency band signal, so that the voltage protection of the loudspeaker can be realized while the displacement protection is realized.

Preferably, the loudspeaker displacement protection device further comprises: the phase adjusting module is connected to a second output end of the second frequency dividing unit and used for outputting a phase adjusting signal according to the second pre-frequency dividing signal, and the phase of the phase adjusting signal is matched with the phase of the frequency band signal;

and the output module is connected to the output end of the phase adjustment module and is also used for superposing the frequency band signal after gain control and the phase adjustment signal and outputting driving voltage.

According to the scheme, the phase of the second pre-frequency-division signal is matched with the phase of the frequency band signal output by the first frequency-division unit through the phase adjustment module, so that the phase difference between the second pre-frequency-division signal and the frequency band signal output by the first frequency-division unit is eliminated, and the displacement protection accuracy is improved.

Preferably, the output unit comprises a plurality of multiplier sub-units, for multiplying each frequency band signal by a corresponding gain, and outputting the frequency band signal after gain amplification; and the addition subunit is used for adding all the frequency band signals subjected to gain amplification and outputting the driving voltage.

The circuit is simple in structure and easy to realize.

Preferably, the displacement gain control unit is further configured to output a corresponding displacement gain according to a comparison result between a sum of the displacement data of each data point and a preset threshold.

According to the scheme, the displacement gain is output by comparing the sum of all the displacement data with the preset threshold value, compared with a method for comparing peak values of displacement data in the prior art, inaccuracy caused by comparison of the peak values is avoided, displacement frequency bands with large absolute values are preferentially processed, energy signals of all frequency bands are released, and the performance of the loudspeaker is improved.

Preferably, the loudspeaker displacement protection device further comprises: and the down-sampling module is connected between the frequency dividing module and the displacement module and used for reducing the sampling frequency of the circuit.

According to the scheme, the sampling frequency of the circuit is reduced through the down-sampling module, and the calculated amount is reduced.

Preferably, the loudspeaker displacement protection device further comprises: the buffer modules are connected with the output ends of the frequency division modules, have preset signal delay time and are used for delaying the frequency band signals by time, and the signal delay time is the time for changing the displacement gain to a preset gain value; and the output module is also used for carrying out gain control on the corresponding delayed frequency band signal according to the displacement gain.

According to the scheme, the buffer module can be used for adjusting the gain of the frequency band signal after the displacement gain is changed to the preset gain value, so that the loudspeaker is prevented from generating plosive.

A loudspeaker displacement protection method comprises the following steps: dividing the frequency of the input audio signal and outputting a plurality of frequency band signals with consistent phases; outputting corresponding displacement data according to the frequency band signals; and performing gain control on the corresponding frequency band signals according to the displacement data, and outputting the frequency band signals subjected to gain control to a driving end of a loudspeaker after the frequency band signals subjected to gain control are superposed.

Preferably, the step of performing gain control on the corresponding frequency band signal according to the displacement data, and outputting the frequency band signal after the gain control to the driving end of the speaker after the frequency band signal is superimposed specifically includes: outputting a displacement gain corresponding to each frequency band signal according to a comparison result of the sum of the displacement data of each data point and a preset threshold; and performing gain control on the frequency band signals according to the corresponding displacement gains, and outputting the frequency band signals subjected to gain control to a driving end of the loudspeaker after the frequency band signals are superposed.

Preferably, before the step of dividing the frequency of the input audio signal and outputting a plurality of frequency band signals with the same phase, the loudspeaker displacement protection method further includes the steps of: pre-dividing the input audio signal according to a pre-dividing threshold value, and outputting a first pre-dividing signal and a second pre-dividing signal which have the same phase; the step of dividing the frequency of the input audio signal and outputting a plurality of frequency band signals with consistent phases specifically comprises: performing secondary frequency division on the first pre-frequency division signal, and outputting a plurality of frequency band signals with consistent phases; the step of outputting the frequency band signal after gain control to the driving end of the loudspeaker after superposition specifically comprises: and superposing the frequency band signal subjected to gain control and the second pre-frequency division signal and outputting the superposed frequency band signal to a driving end of a loudspeaker.

Preferably, before the step of superimposing the gain-controlled frequency band signal and outputting the superimposed signal to the driving end of the speaker, the speaker displacement protection method further includes the steps of: outputting corresponding voltage gain according to the frequency band signal; the step of performing gain control on the frequency band signal according to the corresponding displacement gain specifically includes: comparing the displacement gain with the voltage gain and outputting a comparison gain; and carrying out gain control on the corresponding frequency band signal according to the comparison gain.

Preferably, the method further comprises the following steps: matching the phase of the second pre-frequency-division signal with the phase of the frequency band signal output by the first frequency-division unit; the step of outputting the frequency band signal after gain control and the second pre-frequency division signal to the driving end of the speaker after superposition specifically includes: and superposing the frequency band signal after gain control and the second pre-frequency division signal after phase matching and outputting the driving voltage.

Preferably, the step of outputting the displacement gain corresponding to each frequency band signal according to the comparison result between the sum of the displacement data of each data point and a preset threshold specifically includes: and outputting corresponding displacement gain according to the comparison result of the sum of the displacement data of each data point and a preset threshold value.

Preferably, the step of outputting a corresponding displacement gain according to the comparison result between the sum of the displacement data of each data point and a preset threshold specifically includes: when the sum of all the displacement data is between a first preset threshold and a second preset threshold, outputting all the displacement gains as fixed values; when the sum of all the displacement data is larger than the first preset threshold value, adjusting the numerical value of all the displacement data with the numerical value being a positive value so as to enable the sum of all the adjusted displacement data to be smaller than the first preset threshold value;

or when the sum of all the displacement data is smaller than the second preset threshold, adjusting the numerical values of all the displacement data with the numerical values being negative values so as to enable the adjusted sum of all the displacement data to be larger than the second preset threshold; and outputting a displacement gain corresponding to the displacement data.

Preferably, before the step of performing gain control on the corresponding frequency band signal according to the displacement data, the loudspeaker displacement protection method further includes the following steps: delaying the frequency band signal by the time when the displacement gain is changed to a preset gain value; the step of performing gain control on the corresponding frequency band signal according to the displacement gain specifically includes: and carrying out gain control on the corresponding delayed frequency band signal according to the displacement gain.

An electronic device comprising a loudspeaker displacement protection device as described in any of the above.

According to the loudspeaker displacement protection device, the frequency division module is used for carrying out frequency division on the input audio signals and outputting a plurality of frequency band signals with consistent phases, and because phase difference does not exist between every two frequency band signals, the influence caused by phase difference is eliminated when the frequency band signals are superposed, so that the loudspeaker displacement protection accuracy is improved, and the damage caused when the loudspeaker diaphragm displacement exceeds the maximum displacement threshold value is avoided.

Furthermore, the second frequency dividing unit is used for pre-dividing the input audio signal according to a pre-dividing threshold value, separating a first pre-dividing signal with large influence on displacement, and re-dividing the first frequency dividing signal, so that the phase difference among the channel signals is eliminated, the displacement protection accuracy is improved, and the signal processing efficiency is improved.

Furthermore, gain control is performed on each frequency band signal according to the corresponding voltage gain through the voltage gain control module, and the displacement gain is compared with the voltage gain to perform gain control on the corresponding frequency band signal, so that the voltage protection of the loudspeaker can be realized while the displacement protection is realized.

Furthermore, the sampling frequency of the circuit is reduced through the down-sampling module, and the power consumption of the circuit is reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a loudspeaker displacement protection device according to an embodiment of the present application;

fig. 2 is a schematic circuit diagram of a speaker displacement protection device according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a low pass/high pass filter according to an embodiment of the present application;

FIG. 4 is a plot of the amplitude-frequency response of the Butterworth filter of order 2 of FIG. 3;

FIG. 5 is a Bode diagram of the Butterworth filter of order 2 of FIG. 3;

FIG. 6 is a logic diagram of the processing of the displacement gain control unit when the summation result of all the inputted displacement data is greater than the preset threshold value;

FIG. 7 is a logic diagram of the processing of the displacement gain control unit when the summation of all the input displacement data is less than the negative value of the preset threshold according to an embodiment of the present application;

fig. 8 is a circuit diagram of a loudspeaker displacement protection device according to an embodiment of the present application;

fig. 9 is a schematic flowchart of a loudspeaker displacement protection method according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application are clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application. The following embodiments and their technical features may be combined with each other without conflict.

Referring to fig. 1, the loudspeaker displacement protection device of the present embodiment includes a crossover module 1, a displacement module 2, and an output module 3.

The frequency division module 1 comprises at least one first frequency division unit, and is used for dividing the frequency of an input audio signal and outputting a plurality of frequency range signals with consistent phases. Preferably, the frequency-dividing module 1 comprises a first frequency-dividing unit, which is preferably a high-pass or low-pass filter, such as an active filter, a passive filter, etc. The frequency range of each frequency Band signal obtained by frequency division is different, for example, two frequency Band signals, a frequency Band signal Band1 and a frequency Band signal Band2, are obtained by frequency division. The input audio signal range is 0-4Khz, the frequency range of the frequency Band signal Band1 is 0-2Khz, and the frequency range of the frequency Band signal Band2 is 2Khz-4Khz. The phase of each frequency band signal is consistent, which means that there is no phase difference between the frequency band signals. Since the phases of all the band signals are periodic by 360 degrees, if the phase difference between two band signals is fixed to be 360 degrees, the phase difference between the two band signals is 0 degree, i.e. there is no phase difference. For example, if the phase difference between the Band signal Band1 and the Band signal Band2 is fixed to be 360 degrees, there is no phase difference between the Band signal Band1 and the Band signal Band2. At this time, when the Band signal Band1 and the Band signal Band2 are superimposed, the superimposed signals will not be cancelled. Therefore, the frequency division module 1 outputs a plurality of frequency band signals with consistent phases, and all frequency band signals have no phase difference, so that when all frequency band signals are superposed, the superposed signals cannot be offset, and the accuracy of data is improved.

And the displacement module 2 is connected to the output end of the frequency division module 1 and used for outputting corresponding displacement data according to the frequency band signal. Specifically, the displacement module 2 is a displacement model, which is preferably a displacement model of a speaker, and since a diaphragm of the speaker is displaced according to an input frequency band signal, a corresponding functional relationship can be established according to a relationship between the frequency band signal and displacement data of the diaphragm of the speaker, so as to generate the displacement model. The displacement module can output the displacement data of the corresponding loudspeaker according to the input signals of each frequency band.

And the output module 3 is connected to the output ends of the frequency division module 1 and the displacement module 2 and used for performing gain control on the corresponding frequency band signals according to the displacement data, and outputting the frequency band signals subjected to gain control to the driving end of the loudspeaker after being superposed. Specifically, the output module 3 compares the displacement data corresponding to each frequency band data with a displacement threshold, and performs gain control on the frequency band signal according to the comparison result, for example, when the displacement data is greater than the displacement threshold, the gain of the frequency band signal is reduced. And after gain adjustment is carried out on the frequency band signal of each path, all the frequency band signals are superposed, and the driving voltage of the loudspeaker is output. The output module 3 is preferably provided with a gain control unit on each frequency band signal path, the gain control unit is preferably an amplifier, the gain control unit compares the displacement data output by the displacement module 2 with a displacement threshold, if the displacement data is greater than the displacement threshold, the displacement gain value output by the amplifier is less than 1, and the displacement gain value is multiplied by the corresponding frequency band signal to reduce the voltage amplitude of the frequency band signal. If the displacement data is smaller than the displacement threshold value, the amplifier outputs a displacement gain value of 1, namely, the gain adjustment is not carried out on the frequency band signal.

The loudspeaker displacement protection device of this embodiment divides the frequency of the input audio signal through the frequency division module, outputs a plurality of frequency band signals with the same phase, and because there is no phase difference between every frequency band signal, eliminates the influence that brings because the phase difference when each frequency band signal superposes, has improved the accuracy of loudspeaker displacement protection, has avoided the damage that brings when loudspeaker diaphragm displacement exceeds the maximum displacement threshold value.

Since the loudspeaker protection device of the above embodiment divides all the input audio frequencies and inputs all the divided signals to the displacement module for processing, because of multiple data paths, more data are processed in the whole system per unit time, resulting in a larger calculation amount. In order to solve the problem of large calculation amount, the applicant further proposes a new scheme based on the above embodiment, specifically as follows:

referring to fig. 2, a schematic circuit structure of a speaker displacement protection device according to another embodiment of the present invention is shown.

As shown in fig. 2, the crossover module 1 in the speaker displacement protection apparatus of the present embodiment includes: a first frequency-dividing unit 11 and a second frequency-dividing unit 12.

And the first frequency dividing unit 11 is connected to the first output end of the second frequency dividing unit 12, and is configured to perform secondary frequency division on the first pre-frequency-divided signal Y1 and output a plurality of frequency band signals with the same phase. The second frequency dividing unit 12 prescales the input audio signal Din by a prescaler threshold, and outputs a first prescaled signal Y1 and a second prescaled signal Y2 having the same phase. Specifically, the prescaler threshold is 4Khz, the first prescaler signal Y1 is a signal equal to or less than 4Khz, and the second prescaler signal Y2 is a signal greater than 4Khz. The reason why the pre-division threshold is 4Khz in this embodiment is: for a loudspeaker applied to a general mobile phone end, a displacement generation signal of the loudspeaker is mainly a signal within 2Khz, and a signal larger than 2Khz hardly generates displacement, so that frequency band data below 4Khz can include main data for generating displacement, namely, displacement control of the loudspeaker can be realized. The data of frequency bands above 4Khz are not subjected to displacement control processing, so that the data volume to be processed can be reduced, and the signal processing efficiency is improved. In other application scenarios, the pre-frequency-division threshold can be modified to other values, such as 3Khz, 5Khz, according to the actual situation.

The second frequency dividing unit 12 is preferably a frequency divider formed by a set of high-pass filter/low-pass filter, and the core requirement is that there is no phase difference between the two divided frequency band signals, and the amplitude of the superposed signal is equal to the amplitude of the original signal and cannot be adjusted by the frequency divider, so as to further protect the sound quality of the speaker. The second frequency-dividing unit 12 is preferably a butterworth filter.

As shown in fig. 3, the LPF/HPF (low pass filter/high pass filter) in the second frequency-dividing unit 12 is implemented by two 2 nd order butterworth filters, respectively, and the LPF/HPF corresponds to the two 2 nd order low pass butterworth filters/2 nd order high pass butterworth filters. The amplitude-frequency response of the 2 nd order butterworth filter is shown in fig. 4, where the abscissa in fig. 4 is frequency, the ordinate is gain, and the dotted line is the amplitude-frequency response of the cascade of two 2 nd order high/low pass butterworth filters of the same fc (cut-off to frequency), where it can be seen that the signal is attenuated by 6dB (decibels). The solid line in the figure is the superimposed curve, and it can be seen that the amplitude of the solid line at any frequency is 0dB. Thus, using two 2-step high-pass/low-pass Butterworth (Butterworth) filters in cascade as a frequency divider does not produce amplitude adjustments to the final superimposed output signal. Fig. 5 is a bode plot of the 2 nd order butterworth filter of fig. 3. The solid line in the figure is a curve of a 2 nd order low-pass Butterworth filter; the dotted line is the curve of a 2-step high-pass Butterworth filter. The upper graph in fig. 4 is the amplitude versus frequency curve of the filter; the lower graph in fig. 4 is a filter phase versus frequency curve. It can be seen that the phase difference of each frequency point of the 2 nd order low-pass Butterworth filter and the 2 nd order high-pass Butterworth filter is fixed 180 degrees. Therefore, the phase difference between the HPFs/LPFs obtained by cascading two 2-order high/low pass Butterworth filters is 360 degrees. And the phase is periodic by 360 degrees, so the phase difference between the HPF and the LPF obtained by the cascade connection of the high-pass/low-pass Butterworth filters of the 2 nd order is 0 degree, that is, there is no phase difference.

The above embodiment can implement an implementation scheme that there is no phase difference between the separated frequency band signals, and the amplitude of the superposed back signal is equal to the amplitude of the original signal, and is not adjusted by the frequency divider.

The first frequency dividing unit 11 is preferably implemented by a 2 nd order butterworth filter in the second frequency dividing unit 12, and can divide the first pre-divided signal Y1 equal to or less than a pre-division threshold (e.g., 4 Khz) into more frequency Band signals Band (1), band (3) to Band (n), and the specific number of frequency bands to be divided can be determined according to actual requirements. The signals of the frequency bands divided by the first frequency dividing unit 11 have no phase difference, and the original amplitudes of the signals of the frequency bands are not adjusted additionally. The output module 3 is further configured to superimpose the frequency band signal after the gain control and the second pre-frequency-division signal Y2 and output the superimposed signal to a driving end of the speaker. The second frequency dividing unit 12 pre-divides the input audio signal Din according to a pre-division threshold value, separates a first pre-division signal Y1 having a large influence on the displacement, and re-divides the frequency of the first pre-division signal Y1, thereby eliminating the phase difference between the signals of each channel, improving the accuracy of displacement protection and improving the efficiency of signal processing.

The input real-time frequency band signals pass through the displacement model 2 to obtain real-time displacement data of each frequency band signal. Because the displacement data is also phase-shifted, the peak value superposition of the displacement data of each frequency Band signal (Band (1) to Band (n)) cannot be directly taken to calculate the displacement gain corresponding to each frequency Band signal. The gain of each displacement data point should be calculated according to each displacement data point of each frequency Band signal (Band (1) to Band (n)), so that the situation that the calculation result has errors due to phase differences of each frequency Band signal (Band (1) to Band (n)) is ensured. Namely, because the frequency band data are a plurality of data point signals within a period of time, the corresponding displacement data are also a plurality of data points, and because the displacement data corresponding to each frequency band signal output by the displacement module 2 also have phase difference, errors can be brought by directly taking the peak value of each displacement data to calculate the displacement gain of each frequency band signal through superposition. In order to avoid the error of the calculation result of the displacement gain caused by the phase difference of each displacement data, in this embodiment, the output module 3 further includes a displacement gain control unit 31 connected to the output end of the displacement module 2, and configured to output the corresponding displacement gain according to the comparison result between the displacement data and the preset threshold. The displacement gain control unit 31 performs corresponding displacement gain adjustment on each displacement data in the multi-band signal, so that the condition that errors occur in the displacement gain calculation result due to phase differences of the displacement data is avoided, the accuracy of the displacement gain calculation result is improved, fine displacement control is realized, the suppression on the performance of the loudspeaker is avoided, and the final loudness of the sound signal of the loudspeaker is not influenced.

The processing logic of the displacement gain control unit 31 in this embodiment is as follows:

when the summation result of all the input displacement data is in the range of-threshold (preset threshold), the corresponding gain of each frequency band signal is 1, and no adjustment is made. When the summation result of all the input displacement data is greater than threshold, sorting the signals of each Band (frequency Band) from large to small, and only adjusting each Band with a positive signal, wherein the specific processing logic is as shown in fig. 6: starting from fig. 1, it can be seen that the results of sorting the displacement data from large to small are Band1, band5, band2, band3, and Band4. Step11, adjusting the value of Band1 to be consistent with Band5, then summing the data of all bands, and judging whether the value is less than threshold. If the sum is less than or equal to the threshold, updating the value of the Band1 to be threshold-Band5-Band2-Band3-Band4 (ensuring that the sum is just equal to the threshold); if the threshold is greater than the threshold, step12 is entered. Step12, adjusting the values of Band1 and Band5 to be consistent with Band2, then summing the data of all bands and judging whether the value is less than threshold. If less than or equal to the threshold, the values of Band1 and Band5 are both adjusted to (threshold-Band 2-Band3-Band 4)/2 (ensuring that the sum is just equal to the threshold); if the value is greater than the threshold, the next Step is continued, and the Step13 is entered. And repeating continuously until the sum of all Band data is adjusted to threshold, ending, and comparing each Band-adjusted displacement data value with the original displacement data value to obtain the displacement gain of the correspondingly adjusted Band.

When the summation of the input data is less than-threshold, only the input signals are adjusted to be negative bands, and the specific processing logic is shown in fig. 7: the results of starting at start2 to sort the Band shift data from large to small are Band1, band5, band3, band2, band4. Step21, adjusting the value of Band4 to be consistent with Band2, then summing the data of all bands, and judging whether the sum value is larger than-threshold. If the sum is equal to or greater than-threshold, updating the value of Band4 to-threshold-Band 5-Band2-Band3-Band1 (ensuring that the sum is just equal to-threshold); if the sum is less than-threshold, step22 is entered, in which the values of Band4 and Band2 are adjusted to be consistent with Band3, and then the sum of the data of all bands is performed to determine whether the sum is greater than-threshold. If the sum is equal to or greater than-threshold, adjusting the values of Band4 and Band2 to (-threshold-Band 3-Band5-Band 1)/2 (ensuring that the sum is just equal to-threshold); if the value is less than-threshold, the next Step23 is continued. And repeating the steps continuously. Until the sum of the input signals is adjusted to-threshold, the displacement data value adjusted by each frequency band is compared with the original displacement data value, and then the displacement gain of the corresponding frequency band signal can be obtained.

The displacement gain generation method of the embodiment has the following advantages:

1. the situation that the sum of the peak values of the bands is larger than the sum of the actual displacement due to the phase difference of the displacement signals of the bands is avoided, so that the generated gain is too small, and the sound of the loudspeaker is reduced due to the excessive compression of the signals is avoided.

2. And when the absolute value of the displacement exceeds the maximum displacement, the displacement frequency band with a large absolute value is preferentially processed in a descending order, so that small signals of other frequency bands cannot be reduced simultaneously due to the triggering of the displacement protection suppression by the large signal. The potential energy of the loudspeaker, namely the loudspeaker, is exerted, so that on the premise that the displacement of the loudspeaker does not exceed the specified rated maximum displacement of the loudspeaker, energy signals of all frequency bands are released as much as possible, and the performance of the loudspeaker is improved.

In this embodiment, the output module 3 further includes an output unit, and the output unit is configured to output the frequency band signal after gain control to a driving end of the speaker after being superimposed. The output unit specifically comprises a plurality of multiplying subunits M1, M3, mn to M (n + 1) and an adding subunit Add, wherein the multiplying subunits M1, M3, mn to M (n + 1) are used for multiplying each frequency band signal by the corresponding displacement gain and outputting the frequency band signal after gain amplification. The adding subunit Add is configured to Add all the gain-amplified frequency band signals, and output a driving voltage Dout of the speaker.

In the loudspeaker displacement protection device of the above embodiment, because there is a phase difference between the second pre-divided signal Y2 output by the second frequency dividing unit 12 and each frequency band signal output by the first frequency dividing unit 11, which affects the output result after superposition, the applicant further proposes a new scheme based on the above embodiment, further eliminates a phase difference between the second pre-divided signal Y2 and each frequency band signal output by the first frequency dividing unit 11, improves the accuracy of displacement protection,

fig. 8 is a circuit diagram of a speaker displacement protection device according to an embodiment of the invention.

As shown in fig. 8, the speaker displacement protection apparatus of the present embodiment further includes: the device comprises a phase adjusting module 4, a gain compensation module 5, a down-sampling module 6, a voltage gain control module 7 and a buffer module 8.

And the phase adjusting module 4 is connected to the second output end of the second frequency dividing unit 12, and is configured to output a phase adjusting signal according to the second pre-frequency dividing signal Y2, where a phase of the phase adjusting signal matches a phase of the frequency band signal of the first frequency dividing unit 11. Specifically, the second pre-divided signal Y2 is a frequency band signal greater than 4Khz in the input audio signal. The phase adjustment module 4 is used for adjusting the phase of the frequency band signal greater than 4Khz, because the signal less than or equal to 4Khz, i.e. the first pre-divided signal Y1, passes through the first frequency dividing unit 11, the signal less than 4Khz is divided into a plurality of frequency band signals. Since the first frequency-dividing unit 11 itself causes a phase change of the signal, the phase of the frequency band signal is changed from the phase of the original input signal of 4Khz or less. The phase adjustment module 4 is to match the phase introduced by the first frequency dividing unit 11, so that after the frequency band signal larger than 4Khz passes through the phase adjustment module 4, the phase energy of the output phase adjustment signal is consistent with the phase of each frequency band signal output after passing through the first frequency dividing unit 11, and the phase consistency of subsequent displacement gain generation and signal summation is ensured. The present embodiment schematically provides a way to implement phase alignment, and any way to implement phase alignment and ensure phase consistency of signals of different frequency segments is within the scope of the present invention. In this embodiment, the phase adjustment module 4 matches the phase of the second pre-divided signal Y2 with the phase of the frequency band signal output by the first frequency dividing unit 11, so that the phase difference between the second pre-divided signal Y2 and the frequency band signal output by the first frequency dividing unit 11 is eliminated, and the accuracy of displacement protection is improved.

And the gain compensation module 5 is used for increasing the signal gain of each frequency band signal. Specifically, the gain compensation module 5 in each frequency band is used to boost the small signal gain of each frequency band, so as to improve the accuracy of the displacement protection. Since the frequency band of the sound signal is in the range of 20Hz to 20Khz, the sampling rate of the speaker displacement protection device is typically greater than 40Khz. Taking 48Khz as an example, the amount of calculation of the speaker displacement protection device would be greatly increased if the clock of 48Khz is run.

And the down-sampling module 6 is connected between the frequency dividing module 1 and the displacement module 2 and used for reducing the sampling frequency of the circuit so as to reduce the calculation amount of the loudspeaker displacement protection device. Because the loudspeaker displacement is generated by the signals below 2Khz, the down-sampling can be carried out, and the specific down-sampling multiple can be set according to the actual situation, so that the multiband displacement protection is carried out by using a lower clock, and the calculated amount is saved.

And the voltage gain control module 7 is connected to the output end of the gain compensation module 5 and is used for outputting corresponding voltage gain according to the frequency band signal. Because, still there is the problem that voltage super threshold leads to the speaker to damage among the speaker displacement protection device, in order to solve the voltage protection problem, the speaker displacement protection device of this embodiment still includes: and the voltage gain control module 7 outputs corresponding voltage gains Gainv (1), gainv (3), gainv (n) to Gainv (n + 1) according to the frequency band signal. At this time, the output module 3 further includes a comparing unit Min, the comparing unit Min is connected to the output ends of the voltage gain control module 7 and the displacement gain control unit 31, and is configured to compare the displacement gains Gainx (1) and Gainx (3) to Gainx (n) with the voltage gains Gainv (1), gainv (3), and Gainv (n) correspondingly, and output a comparison gain, and the multiplying sub-units M1, M3, and Mn in the output unit are further configured to perform gain control on the corresponding frequency band signals according to the comparison gain. Specifically, there are both the displacement gain Gainx generated by the displacement protection and the voltage Gainv generated by the voltage protection for the Band signals Band (1) to Band (n) smaller than 4Khz. Therefore, the gain x and the gain v corresponding to the same frequency band signal need to be reduced through the comparison unit Min to serve as comparison gains, and then the comparison gains are multiplied to the signal path, so that the sum of the finally superposed signals of all frequency bands can meet the requirement of not exceeding the maximum voltage and can also meet the requirement of not exceeding the maximum displacement. It should be noted that the control logic of the voltage gain control module 7 is in principle the same as that of the displacement gain control unit 31, but the control object is not the same, and is voltage rather than displacement. Because the input audio signals are in one-to-one correspondence with the voltages, the voltage gain control module 7 can be used for generating the voltage gains Gainv (1) to Gainv (n + 1) of the corresponding multiple frequency bands without an additional displacement model.

The voltage gain generation mode of the voltage gain control module 7 in the multiband voltage protection has two advantages:

1. the conditions that the sum of the peak values of the frequency Band signals is larger than the sum of the actual voltage due to the phase difference of the voltage signals of the frequency Band signals Band (1) to Band (n), so that the generated gain is too small, excessive compression is caused, and the sound is reduced are avoided.

2. Each time of voltage protection and gain processing, only the voltage frequency band with the large absolute value under the condition that the absolute value of the voltage exceeds the maximum voltage is processed preferentially, and the small signals of other frequency bands are ensured not to be simultaneously reduced due to large signal trigger voltage protection suppression from large to small. The potential of the horn is exerted, so that the energy signals of all frequency bands are released as much as possible on the premise that the displacement of the horn does not exceed the maximum voltage.

And the buffer module 8 is connected to the output end of the frequency division module 1 and is used for time-delaying the frequency band signal. Because the displacement gain Gainx and/or the voltage gain Gainv of each frequency band can not be suddenly changed, otherwise POP (POP sound) caused by signal sudden change can be introduced at the loudspeaker end, the displacement gain Gainx and the voltage gain Gainv must therefore be changed to the corresponding gains within a certain time. In order to solve the POP (POP) sound problem caused by sudden change of the speaker-end signal due to instantaneous sudden change of the shift gain Gainx and/or the voltage gain Gainv, the speaker shift protection device in this embodiment further includes: a number of buffer modules 8. The buffer module 8 has a preset signal delay time, and is configured to perform time delay on the frequency band signal, where the signal delay time is a time when the displacement gain changes to a predetermined gain value; at this time, the output module 3 is further configured to perform gain control on the corresponding delayed frequency band signal according to the displacement gain. By adding the Buffer module 8 to each frequency band signal path, the Buffer module 8 is preferably a Buffer (Buffer), the length of the Buffer is matched with the time of the change of the displacement gain Gainx and/or the voltage gain Gainv, the signal is multiplied by the gain which is changed to a preset gain value after being delayed by the Buffer, the displacement and/or the voltage of the finally summed signal are ensured not to exceed the maximum displacement and/or the maximum voltage, and the problem of POP (POP) sound caused by the sudden change of the loudspeaker end signal due to the instantaneous sudden change of the displacement gain Gainx and/or the voltage gain Gainv is solved.

Existing loudspeaker protection schemes do not integrate voltage protection and displacement protection. In practical application of the speaker, because the maximum driving voltage of hardware such as a driving chip of the speaker is limited, voltage protection is required to be matched to prevent clipping or serious distortion of a signal for driving the speaker from affecting subjective hearing or damaging the speaker. This embodiment carries out gain control to each frequency channel signal according to corresponding voltage gain through voltage gain control module to carry out the comparison with displacement gain and voltage gain and carry out gain control in order to carry out gain control to corresponding frequency channel signal, when realizing displacement protection, can realize the voltage protection of speaker, through the module sharing, can resources are saved, also can release more loudness spaces for the voltage protection of single-stage.

The embodiment of the invention also provides a loudspeaker displacement protection method.

Fig. 9 is a schematic flow chart of a speaker displacement protection method according to an embodiment of the invention.

In this embodiment, the loudspeaker displacement protection method includes the following steps:

and S10, frequency division is carried out on the input audio signal, and a plurality of frequency band signals with consistent phases are output.

For example, the frequency divider divides the frequency of the input audio signal, so as to separate two frequency Band signals, i.e., the frequency Band signal Band1 and the frequency Band signal Band2, and also separate more frequency Band signals. The phase of each frequency band signal is consistent, which means that there is no phase difference between the frequency band signals. Since the phases of all the band signals are periodic by 360 degrees, if the phase difference between two band signals is fixed to be 360 degrees, the phase difference between the two band signals is 0 degree, i.e. there is no phase difference. For example, if the phase difference between the Band signal Band1 and the Band signal Band2 is fixed to be 360 degrees, there is no phase difference between the Band signal Band1 and the Band signal Band2. At this time, when the Band signal Band1 and the Band signal Band2 are superposed, the superposed signals cannot be offset and the like. Therefore, the frequency division module 1 outputs a plurality of frequency band signals with consistent phases, and all frequency band signals have no phase difference, so that when all frequency band signals are superposed, the superposed signals cannot be offset, and the accuracy of data is improved.

And S20, outputting corresponding displacement data according to the frequency band signals. For example, the frequency band signal is output to the corresponding displacement data through the displacement model of the loudspeaker.

And S30, performing gain control on the corresponding frequency band signals according to each displacement data, and outputting the frequency band signals subjected to gain control to the driving end of the loudspeaker after the frequency band signals subjected to gain control are superposed.

Specifically, the displacement data corresponding to each frequency band data is compared with a displacement threshold, and the gain control is performed on the frequency band signal according to the comparison result, for example, when the displacement data is greater than the displacement threshold, the gain of the frequency band signal is reduced. And after gain adjustment is carried out on the frequency band signal of each path, all the frequency band signals are superposed, and the driving voltage of the loudspeaker is output. For example, an amplifier is used to perform displacement gain control, and if the displacement data is greater than a displacement threshold, the displacement gain value output by the amplifier is smaller than 1, and the displacement gain value is multiplied by the corresponding frequency band signal to reduce the voltage amplitude of the frequency band signal. If the displacement data is smaller than the displacement threshold value, the amplifier outputs a displacement gain value of 1, namely, the gain adjustment is not carried out on the frequency band signal.

According to the loudspeaker displacement guaranteeing method, the input audio signals are subjected to frequency division, a plurality of frequency band signals with the same phase are output, and due to the fact that phase difference does not exist between every two frequency band signals, influences caused by phase difference are eliminated when the frequency band signals are overlapped, the loudspeaker displacement protection accuracy is improved, and damage caused when loudspeaker diaphragm displacement exceeds a maximum displacement threshold value is avoided.

Before step S10, the loudspeaker displacement protection method further includes the steps of: the input audio signal is prescaled according to a prescaler threshold value, and a first prescaled signal and a second prescaled signal which are consistent in phase are output. The step S10 specifically includes: and carrying out secondary frequency division on the first pre-frequency division signal, and outputting a plurality of frequency band signals with consistent phases. Specifically, the first prescaled signal is a signal of 4Khz or less, and the second prescaled signal is a signal of 4Khz or more. The reason why the pre-division threshold is 4Khz in this embodiment is similar to that described above, and is not described here again. The step of outputting the frequency band signal after gain control to the driving end of the loudspeaker after superposition specifically comprises: and superposing the frequency band signal subjected to gain control and the second pre-frequency division signal and outputting the superposed frequency band signal to a driving end of the loudspeaker. The input audio signal Din is subjected to prescaled frequency division according to a prescaled frequency threshold value, a first prescaled frequency signal with large influence on displacement is separated, the first prescaled frequency signal is subjected to frequency division again, phase difference among signals of all channels is eliminated, accuracy of displacement protection is improved, and meanwhile efficiency of signal processing is improved.

Step S30 specifically includes: outputting corresponding displacement gain according to the comparison result of the displacement data and a preset threshold; and performing gain control on the frequency band signals according to the corresponding displacement gains, and outputting the frequency band signals subjected to gain control to the driving end of the loudspeaker after the frequency band signals subjected to gain control are superposed. By carrying out corresponding displacement gain adjustment on each displacement data in the multi-band signal, refined displacement control is realized, suppression on the performance of the loudspeaker is avoided, and the final loudness of the sound signal of the loudspeaker is not influenced.

Before the step of outputting the frequency band signals after gain control to the driving end of the loudspeaker after superposition, the loudspeaker displacement protection method further comprises the following steps: outputting corresponding voltage gain according to the frequency band signal; the step of performing gain control on the frequency band signal according to the corresponding displacement gain specifically comprises: comparing the displacement gain with the voltage gain, and outputting a comparison gain; and carrying out gain control on the corresponding frequency band signals according to the comparison gain. Specifically, for Band (1) to Band (n) frequency Band signals of 4Khz or less, there are both the displacement gain Gainx generated by the displacement protection and the voltage Gainv generated by the voltage protection. Therefore, the gain x and the gain v corresponding to the same Band need to be reduced through the comparison unit Min to serve as comparison gains, and then the comparison gains are multiplied to the signal path, so that the sum of the finally superposed signals of all frequency bands can meet the requirement that the maximum voltage is not exceeded, and the requirement that the maximum displacement is not exceeded can be ensured. By performing gain control on each frequency band signal according to the corresponding voltage gain and comparing the displacement gain with the voltage gain to perform gain control on the corresponding frequency band signal, the voltage protection of the loudspeaker can be realized while the displacement protection is realized.

Because phase differences exist between the second pre-frequency-division signal and the frequency band signals output by the first frequency-division unit, and the output result after superposition is influenced, the loudspeaker displacement protection method of the embodiment further comprises the following steps: and outputting a phase adjusting signal according to the second pre-frequency dividing signal, wherein the phase of the phase adjusting signal is matched with the phase of the frequency band signal output by the first frequency dividing unit. And superposing the frequency band signal subjected to gain control and the phase adjustment signal and outputting the driving voltage. Specifically, the second pre-divided signal is a frequency band signal greater than 4Khz in the input audio signal. Since the signal less than or equal to 4Khz, i.e. the first pre-divided signal, passes through the first frequency dividing unit, the signal less than 4Khz is divided into a plurality of frequency band signals, and the phase of the frequency band signals changes with respect to the phase of the original input signal less than or equal to 4Khz. The phase energy of the signal frequency band of 4Khz is adjusted to be consistent with the phase of each frequency band signal after passing through the first frequency division unit 11, so that the phase consistency of subsequent displacement gain generation and signal summation is ensured. The present application schematically provides a method for achieving phase alignment, and any method that can achieve phase alignment and ensure phase consistency of signals of each sub-band is within the scope of the present application. The phase difference between the second pre-frequency-division signal and the frequency band signal is eliminated by matching the phase of the second pre-frequency-division signal with the phase of the frequency band signal, and the displacement protection accuracy is improved.

The step of outputting the corresponding displacement gain according to the comparison result of the displacement data and the preset threshold specifically comprises the following steps: when the sum of all displacement data is between a first preset threshold and a second preset threshold, outputting all displacement gains as fixed values; when the sum of all the displacement data is greater than the first preset threshold value, adjusting the numerical values of all the displacement data with the numerical values being positive values so as to enable the sum of all the adjusted displacement data to be less than the first preset threshold value; or when the sum of all the displacement data is smaller than the second preset threshold, adjusting the numerical values of all the displacement data with the numerical values being negative values so as to enable the sum of all the adjusted displacement data to be larger than the second preset threshold; and outputting a displacement gain corresponding to the displacement data. Here, the first predetermined threshold is a positive predetermined threshold, such as +3, and the second predetermined threshold is a negative predetermined threshold, such as-3. For example, when the summation result of all the input displacement data is within the range of [ -threshold (preset threshold), threshold ], at this time, the corresponding gain of each frequency band signal is a fixed value 1, that is, the displacement gain is not adjusted. When the summation result of all the input displacement data is greater than threshold, the frequency band signals are sorted from large to small, only the frequency band signals with the signal values being positive values are adjusted, the specific processing logic is shown in fig. 6, the processing procedure is the same as that described above, and details are not repeated here. When the summation of the input data is smaller than-threshold, only the frequency band signals with negative signal values are adjusted, the specific processing logic is shown in fig. 7, the processing procedure and advantages are the same as those described above, and are not described herein again.

The displacement gain is output by comparing the sum of all displacement data with the preset threshold, and compared with a method for comparing peak values of displacement data in the prior art, inaccuracy caused by comparison of the peak values is avoided, displacement frequency bands with large absolute values are preferentially processed, energy signals of all frequency bands are released, and the performance of the loudspeaker is improved.

Before the step of performing gain control on the corresponding frequency band signal according to each displacement data, the loudspeaker displacement protection method further includes the steps of: time delay is carried out on the frequency band signal, and the delay time is the time when the displacement gain is changed to a preset gain value; the step of performing gain control on the corresponding frequency band signal according to the displacement gain specifically comprises: and performing gain control on the corresponding delayed frequency band signal according to the displacement gain. Because the displacement gain Gainx and/or the voltage gain Gainv of each frequency band can not be suddenly changed, otherwise POP (POP sound) caused by signal sudden change can be introduced at the loudspeaker end, the frequency band signals are subjected to time delay, and the length of the Buffer is matched with the time of the change of the displacement gain Gainx and/or the voltage gain Gainv, so that the signals are multiplied by gains which are changed to preset gain values after being subjected to the Buffer delay, and the displacement and/or the voltage of the finally summed signals can be ensured not to exceed the maximum displacement and/or the maximum voltage. And finally, summing the signals of all the frequency bands to output voltage. And the displacement gain is changed to a preset gain value, and then the gain adjustment is carried out on the frequency band signal, so that the loudspeaker is prevented from generating plosive.

The embodiment of the invention also provides electronic equipment, such as a mobile phone, a tablet computer and the like, comprising the loudspeaker displacement protection device. The electronic equipment adopts the loudspeaker displacement protection method to carry out displacement protection. Through the loudspeaker displacement protection device, the electronic equipment improves the accuracy of loudspeaker displacement protection, and avoids the damage caused when the loudspeaker diaphragm displacement exceeds the maximum displacement threshold value.

The above-mentioned embodiments are only examples of the present application, and not intended to limit the scope of the present application, and all equivalent structures or equivalent flow transformations made by the contents of the specification and the drawings, such as the combination of technical features between the embodiments and the direct or indirect application to other related technical fields, are also included in the scope of the present application.

Claims (14)

1. A loudspeaker displacement protection device, comprising:

the frequency division module comprises at least one first frequency division unit and is used for dividing the frequency of an input audio signal and outputting a plurality of frequency range signals with consistent phases;

the displacement module is connected to the output end of the frequency division module and used for outputting corresponding displacement data according to the frequency band signal;

and the output module is connected with the output ends of the frequency division module and the displacement module and used for carrying out gain control on the corresponding frequency band signals according to the displacement data and outputting the frequency band signals subjected to gain control to the driving end of the loudspeaker after being superposed.

2. The speaker displacement protection device of claim 1, wherein the output module comprises:

the displacement gain control unit is connected to the output end of the displacement module and used for outputting the displacement gain corresponding to each frequency band signal according to the comparison result of the sum of the displacement data of each data point and a preset threshold;

and the output unit is connected with the displacement gain control unit and the output end of the frequency division module and is used for carrying out gain control on the frequency band signal according to the corresponding displacement gain and outputting the frequency band signal after gain control to the driving end of the loudspeaker after the frequency band signal is superposed.

3. The loudspeaker displacement protection device of claim 1, wherein the crossover module further comprises:

the second frequency dividing unit is used for performing pre-frequency division on the input audio signal according to a pre-frequency dividing threshold value and outputting a first pre-frequency dividing signal and a second pre-frequency dividing signal which are consistent in phase;

the first frequency dividing unit is connected to the first output end of the second frequency dividing unit and used for performing secondary frequency division on the first pre-frequency dividing signal and outputting a plurality of frequency band signals with consistent phases;

and the output module is also used for superposing the frequency band signal after gain control and the second pre-frequency division signal and outputting the superposed frequency band signal to the driving end of the loudspeaker.

4. The speaker displacement protection device of claim 2, further comprising:

the voltage gain control module is connected to the output end of the frequency division module and used for outputting corresponding voltage gain according to the frequency band signal;

the output module further comprises a comparison unit, the comparison unit is connected to the voltage gain control module and the output end of the displacement gain control unit and used for comparing the displacement gain with the voltage gain and outputting a comparison gain, and the output unit is further used for carrying out gain control on the corresponding frequency band signal according to the comparison gain.

5. The loudspeaker displacement protection device of claim 3, further comprising:

the phase adjusting module is connected to the second output end of the second frequency dividing unit and used for outputting a phase adjusting signal according to the second pre-frequency dividing signal, and the phase of the phase adjusting signal is matched with the phase of the frequency band signal;

and the output module is connected to the output end of the phase adjustment module and is also used for outputting the driving voltage after the frequency band signal after gain control and the phase adjustment signal are superposed.

6. The loudspeaker displacement protection device of claim 1, further comprising:

and the down-sampling module is connected between the frequency dividing module and the displacement module and used for reducing the sampling frequency of the circuit.

7. The speaker displacement protection device of claim 2, further comprising:

the buffer modules are connected with the output ends of the frequency division modules, and have preset signal delay time for delaying the frequency band signals in time, wherein the signal delay time is the time for changing the displacement gain to a preset gain value;

and the output module is also used for carrying out gain control on the corresponding delayed frequency band signal according to the displacement gain.

8. A loudspeaker displacement protection method is characterized by comprising the following steps

Dividing the frequency of the input audio signal and outputting a plurality of frequency band signals with consistent phases;

outputting corresponding displacement data according to the frequency band signals;

and performing gain control on the corresponding frequency band signal according to the displacement data, and outputting the frequency band signal subjected to gain control to a driving end of a loudspeaker after the frequency band signal subjected to gain control is superposed.

9. The loudspeaker displacement protection method according to claim 8, wherein before the step of dividing the input audio signal to output a plurality of frequency band signals with the same phase, the loudspeaker displacement protection method further comprises the steps of:

pre-dividing the input audio signal according to a pre-dividing threshold value, and outputting a first pre-dividing signal and a second pre-dividing signal which are consistent in phase;

the step of dividing the frequency of the input audio signal and outputting a plurality of frequency band signals with consistent phases specifically comprises:

performing secondary frequency division on the first pre-frequency division signal, and outputting a plurality of frequency band signals with consistent phases;

the step of outputting the frequency band signal after gain control to the driving end of the loudspeaker after superposition specifically comprises:

and superposing the frequency band signal subjected to gain control and the second pre-frequency division signal and outputting the superposed frequency band signal to a driving end of a loudspeaker.

10. The method according to claim 8, wherein the step of performing gain control on the corresponding frequency band signal according to the displacement data, and outputting the frequency band signal after the gain control to a driving end of the speaker after the frequency band signal is superimposed specifically includes:

outputting a displacement gain corresponding to each frequency band signal according to a comparison result of the sum of the displacement data of each data point and a preset threshold;

and performing gain control on the frequency band signals according to the corresponding displacement gain, and outputting the frequency band signals subjected to gain control to a driving end of a loudspeaker after the frequency band signals subjected to gain control are superposed.

11. The loudspeaker displacement protection method according to claim 10, wherein before the step of superimposing the gain-controlled band signal and outputting the superimposed band signal to the driving end of the loudspeaker, the loudspeaker displacement protection method further comprises the step of outputting the superimposed band signal to the driving end of the loudspeaker

Outputting corresponding voltage gain according to the frequency band signal;

the step of performing gain control on the frequency band signal according to the corresponding displacement gain specifically includes:

comparing the displacement gain with the voltage gain and outputting a comparison gain;

and carrying out gain control on the corresponding frequency band signal according to the comparison gain.

12. The loudspeaker displacement protection method according to claim 10, wherein the step of outputting the displacement gain corresponding to each of the frequency band signals according to the comparison result between the sum of the displacement data of each data point and a preset threshold specifically comprises:

when the sum of all the displacement data is between a first preset threshold and a second preset threshold, outputting all the displacement gains as fixed values;

when the sum of all the displacement data is larger than the first preset threshold value, adjusting the numerical value of all the displacement data with the numerical value being a positive value so as to enable the sum of all the adjusted displacement data to be smaller than the first preset threshold value;

or the like, or a combination thereof,

when the sum of all the displacement data is smaller than the second preset threshold value, adjusting the numerical values of all the displacement data with the numerical values being negative values so as to enable the sum of all the adjusted displacement data to be larger than the second preset threshold value;

and outputting a displacement gain corresponding to the displacement data.

13. The loudspeaker displacement protection method according to claim 8, wherein before the step of performing gain control on the corresponding frequency band signal according to the displacement data, the loudspeaker displacement protection method further comprises the steps of:

delaying the frequency band signal by the time when the displacement gain is changed to a preset gain value;

and performing gain control on the corresponding delayed frequency band signal according to the displacement gain.

14. An electronic device, characterized in that it comprises a loudspeaker displacement protection device according to any one of claims 1-7.

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