TWI651003B - Method for obtaining correction characteristics of earphone regeneration characteristics - Google Patents

Abstract

The input and output terminals of the left and right earphones and the microphone are coupled by electronic circuits, and the system has a characteristic signal output system and a player with an input detection signal system, and the left and right earphones are acoustically coupled, and one of the left and right sides is regenerated by current. The driving measurement signal is used, and the other party converts the reproduced sound through the microphone to detect the signal. Regarding the specific characteristics of the calibration measurement system, the voltage drop of the shared wire of the left and right earphones is deducted by high-precision prediction, and the left and right earphones are obtained. The electrical coupling characteristics determine the acoustic coupling characteristics of the left and right earphones, and the correction characteristics of the specific characteristics of the earphone obtained from the acoustic coupling characteristics are converted into predictable reproduction characteristics.

Description

Method for obtaining correction characteristics of earphone regeneration characteristics

Headphone regeneration characteristics measurement and correction

The terms and symbols (symbols) defined in the request item are the same as in the specification.

Measurement of the regenerative characteristics of the headphones.

Correction of the regenerative characteristics of the headphones.

Portable terminal devices with music playback functions such as mobile phones and smart phones, powerful computing processing functions, a large number of memory and audio signal input and output functions or microphone input functions, which are sufficient for detecting the reproduction characteristics of headphones. .

Fast Fourier transform and mutual conversion between fast Fourier inverse transform and impulse response.

Adaptive modulation. Acoustic signal processing. Least squares method.

The specific acoustic signal processing structure of the smart phone's music player, that is, the signal processing must be a real-time processing, but a signal processing method that can effectively use the mechanism and working principle with a small amount of CPU resources.

The coupling characteristics of the left and right earphones are measured by Japanese Patent Application No. 2015-023144, and the reproduction characteristics of the earphone are calculated, and from this result, the correction characteristics for converting the inherent reproduction characteristics of the earphone into standard characteristics are calculated. The signal source of the detection terminal of this method must be a real-time signal, and the detection signal system must be two systems. Under normal circumstances, the headphone of the smart phone and the detection end of the microphone are the same system. The smart phone obtains the mutual conversion process between the electromotive force of the detecting headphone and the digital signal and the electronic signal of the acoustic input system, which is due to the personal smart phone. The inherent value of the resistance of the conversion unit and the deviation of the capacitance element have slight differences in the left and right characteristics. These left and right characteristic deviations have a significant influence on the detection error of the coupling characteristics of the earphone during the calculation.

In particular, the subtraction calculation process of the voltage drop correction of the common ground line of the left and right earphones is, in many cases, larger than the signal depending on the earphone, and the small error is also a major error cause of the measurement result.

The present invention is a method for greatly improving the above-described error relationship problem and obtaining precise correction characteristics.

The acoustic coupling of the first and second earphones, and the correction of the voltage drop of the common wires of the left and right earphones during the detection of the regenerative characteristics of the earphones

The second, smart phone's microphone input is the same system

Third, since the characteristic of the local feature returns to an unstable sound quality, the sound quality correction must be roughly adjusted roughly.

The sound outlets of the left and right earphones are acoustically coupled, one side is used as a reproduction end of the detection signal, and the other side is used as a microphone for detecting functions. One of the earphones reproduces the detection signal of the terminal, and the other earphone terminal reads the same. The electromotive force is connected to the input of the microphone for measurement, as follows.

First, provide current source signal to the regenerative side earphone.

The second, one output, and one input terminal provide signal input and output for measurement.

Third, the electronic circuit characteristic detection of the terminal, precision detection feedback.

The voltage drop of the wires shared by the fourth and right earphones is precisely corrected by the first, second, and third methods described above, and the coupling characteristics of the earphones are acoustically coupled to calculate the inherent reproduction characteristics of the headphones.

Fifthly, the detailed unevenness intensity characteristic of the intrinsic reproduction characteristic of the earphone is calculated, and smooth correction is appropriately performed, and under the actual use conditions, the reproduced sound of good quality can be obtained stably and comprehensively.

The first and simple method, that is, the acoustic coupling method of the left and right earphones, detects the inherent characteristics of the earphone with high precision.

As a result of the second and first results, the complex characteristics of the unevenness of the detail are obtained, and the acoustic characteristics are detected with high precision by rounding, and appropriate smoothing characteristics are obtained.

Thirdly, based on the results of the first and second results, it is expected that the sound quality of the earphone reproduction characteristic is better, and the sound quality of the corrected earphone is used, and the actually used and stable correction characteristics are obtained based on a certain level of sound quality.

Digital signal processing unit inside PROGRAM‧‧‧ terminal

CTL‧‧‧ is responsible for the operation interface, control, calculation and memory function of the detection system

WG‧‧‧The function of generating digital signals for time series for measurement

START‧‧‧Digital system startup signal

BASE‧‧‧ terminal measuring signal

MES‧‧‧ terminal machine measurement function signal

Wexp‧‧‧ Expected Headphone Features

The inherent characteristics of the electronic circuit unit of the Hsm0‧‧‧ terminal

k, Kmin‧‧ ‧ variable coefficient and the specific value of the influence of K used to remove the common wire

The inherent characteristics of Pep‧‧ headphones

Qep‧‧‧Sound quality correction features for headphones

Uep‧‧‧Intrinsic characteristics of smoothed headphones

Vep‧‧‧Smooth headphones with sound quality correction

DEVICE‧‧‧Determination unit for digital signal and electrical signal

The conversion of Zs‧‧‧ digital signals into electrical signals

The conversion of Zm‧‧‧ electrical signals into digital signals

Cs, Ls, Rs, Ms‧‧‧ are the terminals of the left and right earphones

CONVERT‧‧‧Connecting and wiring unit for terminal and earphone

SW‧‧‧Measurement mode switch

Terminals for Cu, Lu, Ru, Mu‧‧‧ wiring conversion units

Terminals for Cv, Lv, Rv‧‧‧ wiring conversion units

Mv‧‧‧Microphone terminals not used

EARPHONE‧‧ ‧ headphones for measuring objects

Rc‧‧‧Electrical impedance of common wires

Rl‧‧‧Resistance of the wire of the regenerative earphone

Rr‧‧‧Detector wire resistance of the earphone

Impedance and electromotive force of Zl, El‧‧ regenerative headphones

Impedance and electromotive force of Zr, Er‧‧‧ detecting headphones

CP‧‧‧ is the coupling element for the left and right headphones

Terminals for Ce, Le, Re‧‧‧ headphones

Me‧‧‧Microphone terminals not used

1, 2‧‧‧ respective left and right headphones

3‧‧‧Coupling components

4‧‧‧Incoming direction of electronic signals for measurement

5‧‧‧The direction of the reverberant sound of the left earphone to the right earphone

6‧‧‧ Terminal signal of the right earphone

7‧‧‧ headphone plug

The difference point of the earphone wire around 8‧‧

9‧‧‧About the part of the earphone common wire

10‧‧‧ is the common terminal of the left and right earphone wires

11‧‧‧Lead wire for the left earphone

21‧‧‧ wire for right earphone

12‧‧‧ Terminals for left earphone wires

22‧‧‧ Terminals for right earphone wires

A1, b1, c1, d1‧‧‧ terminal voltage of the sensed headphone after correction of the voltage drop of the common conductor

Ab2, b2, c2, d2‧‧‧ inherent regenerative characteristics of earphones after voltage drop of common wires

A3, b3, c3, d3‧‧‧Reconstruction characteristics after correction of the inherent reproduction characteristics of the earphone obtained after the measurement calculation

A4, b4, c4, d4‧‧‧ Calibration characteristics of the inherent regenerative characteristics of headphones

[Fig. 1] An explanatory diagram of a practical example of acoustic coupling coefficient detection of left and right headphones

[Figure 2] Description of the principle of simplification

[Fig. 3] Illustration of the wires, common parts and acoustic coupling of the left and right earphones

[Fig. 4] Example of characteristic detection and sound quality correction of four types of headphones

The most ideal type of invention is an application of a portable terminal for detecting earphone characteristics, a coupling element and a kit for detecting a connection converter, a product for correcting earphone characteristics in a consumer market, and an accessory for headphones.

The possibility of industrial use: the user is not satisfied with the sound quality correction service of the purchased headphones, the musician and the sound quality determiner, the specific music, the specific sound quality, providing the sound quality correction without the earphone type, and the reproduction characteristics through the earphone The correction becomes the expected characteristic as the most suitable characteristic for the weak listener, and the best sound quality correction for the earphone earphone of the noise canceling type earphone.

Fig. 1 is an explanatory diagram of a practical example of detection of the present invention.

The symbols of Figure 1 are the same as described on the request item.

The method of removing the external earphones of the general earphone, the acoustic coupling of the left and right earphones, and the calculation of the earphone characteristics of the detection formula are as shown in the structural diagram. The following description is a supplement to the request.

The coupling element CP serves as an acoustic coupling element for the left and right earphones.

The signal provided by the regenerative side earphone is a current source signal.

The regenerative sound of the regenerative side earphone is transmitted to the detecting end earphone through acoustic coupling to cause the electromotive force of the detecting end earphone. The relative relationship of the detection signals of this electromotive force is related to the conversion characteristics of the earphone. Therefore, the electromotive force of the detecting end earphone is not directly detected. The electronic signal obtained from the earphone terminal of the detecting end earphone must be subtracted from the voltage difference of the common wire of the left and right earphones to calculate the electromotive force of the detecting end earphone generated by the acoustic coupling. The electronic loop characteristics of the digital signal conversion between the digital signal and the electronic signal of the terminal are also taken into consideration to improve the accuracy of the detection. In addition, the purpose of the detection system is to improve the detection accuracy. Because the single-sided channel is used, the characteristics of the electronic circuit and the coupling characteristics of the earphone are bilateral, so switch switching detection is required.

The symbol PROGRAM shown in FIG. 1 refers to a digital signal processing unit inside the terminal, the CTL refers to an operation interface of the control detection system, a function of control, calculation, and storage, and the WG refers to a function of generating a digital signal for detection.

START refers to the signal of the terminal that starts the detection system, BASE refers to the signal of the electronic circuit characteristic detection function of the terminal, and the b and c of the SW described after this time point are connected together, and enter the internal electronic circuit of the terminal. The measurement mode generates Eg0 described in the request item as the detection of Em0, and calculates Zs*Zm, that is, Em0*{1/Eg0}, that is, Hsm0, through the internal fixed number of the terminal.

MES refers to the signal of the function of the electromotive force measurement of the earphone of the terminal of the terminal.

When a and c of the SW described later at this time point are connected, the detection mode of the coupling coefficient of the left and right headphones is entered.

The Eg generated in the request item is generated, and Em is detected. After the error that can be ignored in the request item is removed, the coupling coefficient of the left and right headphones is calculated. Glr Rm*{1/Hsm0}*Em*{1/Eg} .

Wexp refers to the earphone characteristics expected after correction.

Hsm0 refers to the inherent characteristics of the electronic circuit of the terminal that is calculated by calculation.

k, Kmin refers to the variable variable after the removal of the resistance of the common wire of the earphone and the minimum value of K obtained.

Pep refers to the inherent characteristics of the earphones obtained by the detection calculation.

Qep refers to the sound quality correction characteristics of headphones obtained from Rep and Wex.

Uep refers to the inherent characteristics of Rep through smoothing headphones.

Vep refers to the sound quality correction characteristics of headphones obtained from Uep and Wex.

DEVICE refers to the digital signal and electronic signal conversion unit inside the terminal.

Zs refers to the function of converting electronic signals into digital signals.

Zm refers to the function of converting digital signals into electronic signals.

Cs, Ls, Rs, and Ms refer to the common terminal, the left output terminal, the right output terminal, and the microphone input terminal of the left and right earphones of the terminal, respectively. This test example is not using right output. It can be used if it is used separately.

CONVERT refers to the wiring component that connects the terminal to the earphone.

SW refers to the change mode of the detection mode, including three endpoints a, b, and c. When c and b are connected, it is the detection mode of Zs and Zm. When c and a are connected, the coupling characteristics of the left and right headphones are detected. mode.

There are two reasons for switching the detection mode of the switch: The first reason is that the acoustic input force of a general terminal is the same system.

The second reason is the characteristics of the left and right electronic circuits of any terminal. Because of the difference between the resistance and the capacitance, this variable is a factor of large error, and the characteristic detection of the electronic circuit is The detection of the electromotive force of the headphones, both of which must use the same input and output system.

Cu, Lu, Ru, and Mu refer to terminals of the terminal end of the wiring conversion element.

Cv, Lv, and Rv refer to terminals of the headphone end of the wiring conversion element.

Mv is the connection terminal of the wiring conversion element and the microphone terminal of the headphone terminal, and is not used regardless of whether or not there is a microphone.

EARPHONE refers to the detected earphone, Rc refers to the electronic impedance of the common wire of the left and right earphones, and Rc refers to the cause of the largest error in the detection of the coupling coefficient of the left and right earphones. The value of Rc is the maximum difference of the type of earphone, such as the minimum value of the Rc relationship item described in the request item, and the coupling coefficient of the left and right earphones can be accurately measured.

The elimination of the relationship term of Hsm0 measured to the Rc using the correction mode is generated by the signal Ecan, which is k*Hsm0*Eg where k is a variable number and Em contains a relationship term in which Rc is minimized. The relationship of Kmin is described in the seventh function of the request item.

Rl is the resistance of the wire of the regenerative earphone, Rr is the resistance of the wire of the earphone of the detecting end, Rl, Zl, and El means the electromotive force of the impedance of the common terminal of the regenerative side earphone to remove the resistance of the wire, Rr, Zr, Er It refers to the electromotive force of the impedance of the respective common ends of the detecting end headphones to remove the resistance of the wires.

The regenerative sound generated by the detecting headphone is provided, and the current source is a ratio of Rm to ES. This Es is large enough to ignore the effects of El, and Rm is large enough to ignore the effects of Rl and Zl. Es and Rm are determined by the range of common sense of the electrical properties of headphones sold in the market.

Zm is the electromotive force detection of the microphone, and the input impedance of Zm is large enough to ignore the general values of Rl and Zl. Current consumption.

Then, the two electromotive forces from Ec and Er are detected as voltages.

Here, Ec is removed by the seventh function, and Er is measured as an electromotive force coupled by the acoustic coupling of the left and right headphones.

Based on the above reasons

The electromotive force of the acoustic coupling of the detecting end earphone is Eg*Hsm0*{1/Rm}*Glr, which can be expressed very simply.

CP refers to the coupling elements of the left and right earphones, Ce, Le, and Re are the common terminals of the left and right earphones, and are respectively connected to Cv, Lv, and Rv of the accessory conversion portion.

Me is the connection end of the microphone terminal, and it does not matter whether the microphone is used or not.

The following is a supplementary explanation of the calculation method of the electronic circuit characteristic Hsm0 inherent to the terminal of the request.

As described in the request, Hsm0 is an inherent characteristic of the electronic circuit of the terminal, and is the product of the Zs of the signal generating system and the signal detecting system Zm, Zs*Zm.

The detection system consists of two systems. Hsm0 is a simultaneous detection of the electromotive force of the earphone. The characteristic of this case is that the measurement system of one system uses the switch to do the detection.

In addition, Zs*Zm is detected by Em0*{1/Eg0}. This relationship is a constant obtained by the measurement signal Em0 passing through the detection signal Eg0. The frequency range is the frequency range of the general acoustic signal, and the general range of 20 Hz to 20 kHz is quite sufficient.

The commonly used detection signal is white noise in the acoustic signal channel range. The delay time of Em0 and Eg0 can be calculated through the mutual relationship between the two.

The analog conversion of the general output system is the same as the sampling clock of both the digital conversion of the input system, and there is no problem in the calculation. There are very few differences between the two sides of a general-purpose computer. This is an exception. Both the input and output devices of the portable terminal device have the same sampling timing architecture.

Except for the delay time of Em0 and Eg0, Eg0 is the characteristic of the white noise of the reference signal, and the complex number of Em0 is expressed as the electronic circuit of the terminal of the pulse feedback performance.

The calculation of Hsm0 and Glr is necessary, and the order of calculation of the reciprocal of the reciprocal relationship is the field of open signal processing, and has nothing to do with the essence of the patent of the present invention, so detailed description is omitted.

The following is a method for obtaining the acoustic coupling coefficient Glr of the left and right earphones, and the measurement result is the most practical and necessary to supplement the description of the request method of the full Em detection method.

Here, the Hsm0 detected by the previous calculation is used.

The signal Eg supplied by the Ecan, that is, the signal reproduction end of the k*Hsmo*Eg is generated inside the signal processing.

Ecan is an error that causes no delay time to occur, so that the designed signal can be accurately created in advance. Eg is continuously generated, k is a variable number, real-time kmin calculation, and signals are recorded in batches at predetermined times.

One of the methods obtained by kmin is that the internal calculation part of the terminal performs real-time operation, or requires similar real-time processing, and the recorded detection signal is processed in batch processing.

In the method obtained by kmin, k is a variable number, which is necessary because the minimum k of the ABS (Em-Ecan) described in the request item is obtained.

If Hsm0 and delay time are one of the parameters of GLR calibration, not the same sampling clock Element, for example, when the sampling rate period of the signal output and the signal input has a half-cycle error, the acoustic coupling conversion delay time of about 30 milliseconds to 100 milliseconds, if the odd-numbered time calculation of the sampling rate for the calculated delay time is assumed The ratio of the sampling time before the sampling point to the next sampling time, and the ratio of the previous sampling value to the next sampling value, at which time the approximate value of the sampling value can be calculated.

The following is a supplementary explanation of the relationship between Rep*Rep and Qep and Uep*Uep and Vep described in the request.

One of the left and right earphones' acoustic couplings is the regenerative end, and the other end is the detecting end. The coupling characteristics of the earphones of the detecting end and the regenerative characteristics of the earphone are calculated. Since the series is connected, the earphones maintain the same switching characteristics, and the coupling characteristics depend on the regenerative characteristics. The square of the fact that the square of the same regenerative characteristics corresponds to the coupling characteristics.

The following is a supplementary explanation for the removal ratio item in the request item.

The scaled off term of the narrative in the request item is due to the fact that humans are sensitive to the logarithm of the horizontal axis of the acoustic characteristic and the vertical intensity axis.

The acoustic characteristic of the earphone, the specific proportional coefficient multiplication of Rep or Uep is the same as the addition of the full frequency band of the logarithmic axis, and attempts to change the proportional coefficient contained in Rep or Uep. The mode of this characteristic is the parallel movement of the vertical axis, so The nature of the sound quality is not changed. The tentative conclusion is that even if there is a proportional coefficient in Rep or Uep, in the final method of sensitivity adjustment, the practical stage will be adjusted.

Therefore, the {1/Rm} item contained in Em-Ecan can be ignored.

Qep is expressed as {1/Rep}, which is the inverse of Rep.

Usually any Rep can calculate the inverse function as a feasible constant, but it is not limited. However, within a limited condition, a plurality of but a few kinds of parameter adjustments can constitute the closest filter. Waves.

For example, the parameter adjustment of 12 secondary filters can also be approximated, even if a secondary filter can determine the closest parameter.

Rep is calculated corresponding to the frequency response, and the inverse correlation number can also be calculated from the frequency response. In addition, within the range of the variable range of the given TAP number, the inverse of the Rep can be calculated by adjusting the TAP coefficient of the FIR filter.

These are well-known techniques, and thus detailed descriptions are omitted.

The following is a supplementary explanation of the method of requesting the Rep calculation Uep based on the processing operation of the smoothing process.

The characteristics at a particular frequency, on how to obtain an approximate mean, is that the human auditory sense is expressed in logarithmically for the corresponding intensity on the frequency axis. The general practice is to average the logarithmic intensity of the range of the logarithmic frequency axis. .

The simplest method is to convert the normal linearity of the frequency axis by Fourier transform. The vicinity of this frequency, the strength of the logarithmic axis is necessary. The specific coefficient of one of the methods, for example, 1/8 of the logarithm of the octave or 1/16 or 1/32, calculates the sum of the geometric mean of the intensities on these frequency axes. These must be performed in the full frequency band to find all smoothing characteristics. After calculating the sum average of the geometric mean values of the intensities, a method of determining the degree of frequency dispersion is obtained.

In addition, the condition group setting that may represent the curve in a specific frequency range, the curve that can be expressed within the specification range of this condition group, is one of the methods for obtaining the curve closest to the original characteristic. This condition can be represented by a curve, for example, a parameter group sum represented by a function whose curve is determined according to the number of times the curve is set, and a boundary condition group seeking curve as a limiting factor of the function.

There are several ways to get it. The method of using the least square method is the only one with the most expected characteristics. The method of approximating the parameter group of the performance curve, on the basis of adaptive control, while searching for parameters, finds the method that represents the most approximate parameter group. Boundary conditions are, characteristics within the range, values at both ends, slope, and maximum slope. In summary, these methods of smoothing are well known and are different from the essence of the present invention, so detailed descriptions are omitted.

As described above in the specification and the claims, the first, second, and third items of the problem to be solved can be solved by the problem, the first, second, third, and fourth items of the method used. Item 5 is resolved.

Figure 2 is a block diagram of a simplified schematic of the principle. Fig. 1 of the request item is a structure for correct processing of signal processing for improving detection accuracy, and Fig. 2 is a simple representation of actual use obtained by removing unnecessary factors. In order to improve the detection accuracy, the signal of the detection system is originally current source, which can ignore unnecessary factors. Then, by knowing the characteristics of the electronic circuit, adaptive control can remove the unnecessary factors of the measurement object, only the terminal The function in the device detects the coupling coefficient of the left and right headphones. The expression of the calculated symbol is the same as the request item.

The current source signal is applied to the regenerative earphone, and the digitized phase of the electromotive force of the terminal of the detecting end earphone is the sum of the voltage drop of the common wire and the acoustic coupling electromotive force of the earphone of the detecting end. Ec*Zm uses the coefficient K generated by Ecan to cancel out to detect Hsm0.

Therefore, the expression of Er, Glr*Eg*Zs*Zm*{1/RM}, that is, the detected value of Glr*Eg*Hsm0*{1/RM} is extracted during the calculation process.

Here, Rm is a proportional coefficient, which has nothing to do with the sound quality correction and can be deleted.

Eg and Hsm0 are factors known to the detection system, and therefore, Glr can be calculated as Rm*{1/Hsm0}*{Em-Ecan}*{1/Eg}. Glr is a display of the performance values of the design values and the precision measured values, all of which are completely unknown except for the proportionality coefficient Rm.

An important advantage of this patent is that, by measurement, the characteristics of the electronic circuit of the terminal device are known to be constant, the electronic signal of the earphone of the detecting terminal is a current source, and the microphone input force of the terminal device is used with respect to the high impedance of the earphone, and the terminal device is used. The high-impedance of the microphone input force relative to the earphone is a factor that cannot be measured according to the adaptive control, and the resistivity of the common wire of the earphone is removed with high precision.

Figure 3 is an explanatory view of the wires and the shared portions of the left and right earphones and the acoustic coupling. The earphones of the general earphones are used to display the acoustic coupling of the left and right earphones.

1 and 2 are the left and right earphones, 3 are the coupling elements, 4 is the input direction of the electronic signal for detection, 5 is the direction in which the reproduced sound of the left earphone is transmitted to the right earphone, 6 is the terminal signal of the right earphone, 7 is Headphone plug, 8 is the divergence point of the wires of the left and right earphones, 9 is the part of the common wire of the left and right earphones, 10 is the common terminal of the left and right wires, 11 is the wire of the left earphone, 21 is the wire of the right earphone, 12 is the left earphone The terminals of the wires, 22, are the terminals of the wires of the right earphone.

The length of the common part of the left and right grounding wires varies depending on the general type of the earphone, and one of the grounding wires is not commonly connected. Generally, the internal wiring of the earphone plug and the internal wiring of the portable terminal have a common grounding portion of the left and right earphones. Strictly speaking, all the common grounding wires of the earphones exist.

Depending on the general category of the headset, some have an attached microphone, but the microphone has or does not have a microphone terminal that is not connected to the detection system.

Fig. 4 is a practical example of the present invention, characteristic correction, calculation characteristics, correction characteristics, and corrected reproduction characteristics of four commercially available earphones.

The fine sawtooth characteristics are mostly due to the fact that the input signal is white noise. This is not a detection pair. The earphone characteristics of the elephant. It contains very fine ripples of local resonance, and these subtle sound quality characteristics are not felt in the general music. The expected reproduction characteristic Wexp is 1, that is, in the case where the expected characteristic is flat, the frequency band below 40 Hz of the characteristic map has significant bass attenuation, which is because of the characteristics of the FFT for characteristic observation, which does not represent the operation result itself. .

Figure 4(a) shows an example of the weakest regenerative strength of the lowest bass in the market.

Figure 4(b) shows an example of strong resilience of the higher-priced bass in the market.

Figure 4(c) is an example of the highest market price.

Figure 4(d) shows the result of an example of the most popular price in the market.

A1, b1, c1, and d1 are the calibration results of the voltage drop of the common wire.

A2, b2, c2, and d2 are the reproduction characteristics inherent to the earphone obtained from the electromotive force of the corrected side earphone after subtracting the voltage drop of the common wire.

A3, b3, c3, and d3 are the original reproduction characteristics of the earphone obtained based on the measurement calculation result, and the reproduction characteristics of the correction operation of the expected characteristic

A4, b4, c4, and d4 are obtained from the calculation results, from the original reproduction characteristics of the earphone to the correction characteristics of the expected characteristics.

The 4 headphones have their own characteristics, and the sound quality of the actual use is significantly different. In the case of the four types of Wex 1, after the characteristics are corrected to be flat, what quality is required after the corrected sound quality is corrected, depending on the user's preference, so Wexp is generally an arbitrary sound quality characteristic.

In addition, in the wearing state of the earphone, the depth of the wearing has a great influence on the reproduction characteristics of the bass, and the angle of the wearing state and the reproducing characteristics of the high sound have a great influence. For these reasons , expecting the default characteristics of the basic standard wearing state of the feature.

The corrected characteristics are not completely flat. How is the flatness in general, how much, how close to the expected attributes, and whether the degree is good or bad. The fine concavities and convexities depend on the local resonance and the standing wave in the wearing state, and enter the characteristic category in which the actual use state is unstable. Unstable characteristics are not natural sound quality effects. As an example of one of the correction results, the finer correction of the high frequency band has actually deviated from the small scale wave and has no meaningful sound quality. Fig. 3 is an example of correction of the practical range of moderate accuracy.

Claims (2)

A method for obtaining a correction characteristic of a reproduction characteristic inherent to an earphone into a desired reproduction characteristic includes: a terminal device refers to an output of an acoustic signal such as a smart phone or a mobile phone or a player or a computer, and the characteristic refers to a gain intensity of the frequency. , intensity refers to the corresponding value of the effective value or the average or maximum value, the maximum value of the signal or characteristic or gain, the detection signal refers to the white noise or sine wave scanning signal or square wave of the acoustic frequency can be used as the earphone The signal of characteristic detection; the mark +-*/ each represents addition, subtraction, multiplication, division operator and operation within {}, which takes precedence over {} external operation; F( ), F is function, and F is represented by ( ) Function and calculation of related variables; ( ) of ABS( ) indicates the strength of the internal variable; >> indicates that the variable on the left is greater than the strength of the variable on the right; the inherent characteristic of the earphone means that the specific earphone has its own acoustic input corresponding to the current input. The frequency response characteristic; the coupling component refers to the connecting component of the acoustic output end of the left and right earphones; the regenerative side earphone refers to the earphone that plays the electronic signal for detection; The out-side earphone refers to a headphone that connects the regenerative side earphone through a coupling element and converts the regenerated acoustic signal into a power signal; the acoustic coupling means that the electromotive force is generated through the coupling element and generates an electromotive force from the detecting side earphone; in order to perform measurement, the terminal must be used. The digital signal processing function of the machine generates digital signals to perform digital signal conversion and calculation processing; and the Eg is an index signal for detecting index signals. The first function is the function of generating Eg; the Em is the detection signal converted into the digital signal, the second function is the function of obtaining the Em; the ZS is the conversion characteristic of the index signal converted into the electronic signal; the Zm is the electronic signal The conversion characteristic electronic circuit is converted into a digital signal; Rm means that the regenerative side earphone needs to be connected to the series resistor in order to convert the signal of the regenerative side earphone into a current source signal, and the third function can use Rm in series; the Rc is the common line of the left and right earphone wires. Part of the resistance; Rl is the regeneration side minus the resistance of the common unit of the common conductor; Rr is the detection side minus the resistance of the common unit of the common conductor; Zl is the impedance of the electroacoustic conversion unit of the regenerative side earphone; Zr is the acoustic of the earphone of the detection side The impedance of the electronic conversion unit; the electromotive force of the earphone of the El-generation regenerative side; the electromotive force of the earphone of the ER-detecting side; the voltage drop of the Ec-based common-purpose earphone; the current flowing by the Glr-based regenerative earphone corresponds to the electromotive force generated by the detecting side earphone The coupling coefficient; k is a variable proportional variable; the use of the above symbols is as follows: Rm, Rc, Rl, Rr, and k are not plural The proportional coefficients with delay, Zm, ZS, Zl, ZR, Jep, Rep, Qep, Wex, Uep, and Vep are complex numbers, Eg, Em, Ec, El, Er, Emc, Eg0, Em0, and Ecan are digits. Signal, Hsm0, Glr are processed according to the digital signal of the terminal by complex and delay time. Constant; representative of Em system F (Eg, Zs, Rm, Rc, Rl, Rr, Zl, Zr, El, Er, Zm), which is relationship 1; condition 1 is Rm>>Rc; condition 2 is Rm>> Rl; condition 3 is Rm>>ABS(Zl); condition 4 is Rm>>ABS(Zr); condition 5 is ABS(Eg*Zs)>>ABS(El); five conditions of numbering conditions 1~5 above The detection electronic signal for the regenerative side earphone is a high output impedance signal source, so the influence of Rc, Rl, Zl, Zr and El can be neglected, which is why it is a current signal source; condition 6 is ABS ( Zm input impedance)>>Rc; Condition 7 is ABS (Zm input impedance)>>Rr; Condition 8 is ABS (Zm input impedance)>>ABS(Zr); three conditions of the above numbering conditions 6~8 The terminal voltage of the detecting side earphone is Rc and Rr and ABS (Zr) are unaffected high input impedance measuring circuits to some extent, and the eight conditions of the numbering conditions 1 to 8 described above are relational expression 1; Em=F(Eg, Zs, Rm, Rc, Er, Zm) is a expression obtained by using the relation 1, and Ec=Ec*Zm is measured by Eg*Zs*{1/Rm}*Rc*Zm. The digital signal, which is the relation 2; the current flowing through the head of the regenerative side uses the formula Eg*Zs *{1/Rm} is calculated, Er is the current flowing through the head of the regenerative side, and is the value obtained by multiplying the coupling coefficients of the left and right earphones. Er is Er*Zm, that is, using Eg*Zs*{1/Rm} *Glr*Zm calculates the measured digital signal, which is the relation 3; according to the relationship 2 and the relation 3 Em is the addition of Ec*Zm and Er*Zm The value of Em can be expressed by {Eg*Zs*{1/Rm}*Rc*Zm}+{Eg*Zs*{1/Rm}*Glr*Zm}, which is relation 4; Eg0 is detected. The side earphones are connected to the headphone output terminal and the microphone input terminal to reproduce the digital signal. Em0 is the digital signal detected by Eg0 through the electronic circuit of the terminal. Hsm0 is Em0*{1/Eg0}, and Hsm0 is Zs*Zm. That is, any signal that uses Eg in the detection range is a constant characteristic, and the inherent constant of the terminal electronic circuit on the path through which the signal is detected is detected from the signal source. This is the relation 5; the method obtained by Hsm0 is Disconnect the input terminal of the detecting end earphone to the microphone terminal of the terminal, and connect the regenerative side earphone terminal of the terminal to the microphone terminal. The fourth function is to obtain the function of Hsm0; the relation 4 is substituted into the relation 5, and Em is The substituted representation is {Hsm0*Rc*{1/Rm}*Eg}+{Hsm0*Glr*{1/Rm}*Eg}; Ecan is k*Hsm0*Eg is a digital signal, and the fifth function is to generate Ecan The function of the ABS (Er*Zm)>>ABS (Ec*Zm-Ecan), which is the minimum of ABS (Ec*Zm-Ecan), ABS (Em-Ecan) is minimized, Ecan is used to find the intensity coefficient of k, kmin is equal to k at this time, and the sixth function is to find the function of kmin; kmin is actually used for Em-Ecan={Hsm0*Glr*{1 In the formula of /Rm}*Eg}, that is, the minimum Em-Ecan of ABS (Em-Ecan); Glr is the coupling coefficient of the left and right headphones, Rm*{1/Hsm0}*{Em-Ecan}* {1/Eg} can be used as a measurement. The function of the seventh function is the coupling coefficient Glr of the left and right earphones; Rm in this coupling coefficient Glr is a proportional coefficient, which is the sound quality of the coupling coefficient with the earphone. The unrelated factor, the formula after the removal of Rm {1/Hsm0}*{Em-Ecan}*{1/Eg} represents the result of the left and right earphone measurement calculations for all known value items obtained at the terminal side; Pep*Pep Equal to {1/Hsm0}*{Em-Ecan}*{1/Eg}, Pep is the measured sound quality characteristic of the earphone, which is the relation 6; Wexp is the corrected characteristic obtained by the sound quality correction operation. , Wexp is a case including 1, assuming a selectable characteristic; Qep is equal to {Wexp/Pep}, Qep is the correction characteristic of the sound quality Wepro inherent to the earphone, and the eighth function is the function calculated by Qep; the ninth function In order to consider Qp's proportional coefficient together, A is a specific constant, and A*Qep is the function of the sound quality correction characteristic inherent to the earphone; the 8th and 9th functions are all functions determined by the sound quality correction characteristic; the 10th function is The sound quality correction function determines the function, including the 8th function and the ninth function, which can be used or used at the same time; the second function generated by the digital signal of the measurement signal, the second function of the digital signal of the detection signal, and the serial connection The Rm conversion signal is the third function and terminal of the current source signal. The fourth function of the fourth function of the digital signal and the electronic signal conversion control unit, the fifth function of the signal for eliminating the electromotive force of the common line of the earphone, and the sixth function of the coefficient of the signal for determining the electromotive force of the common line of the earphone, The seventh function of calculating the coupling coefficient of the left and right earphones, and the tenth function of calculating the inherent sound quality correction characteristic of the measured earphone, through the combination of the first, second, third, fourth, fifth, sixth, seventh, and tenth functions, Avoid the influence of different errors of the left and right electronic circuit units of the terminal, and correct the influence of the inherent characteristics of the terminal, and remove the influence of the voltage drop of the common wires of the left and right earphones with high precision, and increase the measurement of the acoustic coupling characteristics of the left and right earphones. The accuracy and the inherent reproduction characteristics of the obtained earphones are obtained by converting the correction characteristics into the expected reproduction characteristics. A method for obtaining a correction characteristic of converting a reproduction characteristic inherent to an earphone to an expected sound quality characteristic, comprising: a Pep represented by an eighth relational expression of the request item 1 is a specific feature of the earphone, smoothing a minute unevenness having an intensity characteristic, and a smoothing The characteristics and functions of the smoothing function, the smoothing function smoothing characteristics are used for smoothness, the inherent earphones are characterized by a smoothing function, the smoothing characteristics of the frequency of a certain point, and the average functional frequency of the representative functional characteristics in the vicinity thereof are used for calculation. The average of the full-band obtained by the average of the intensities, the eleventh function is the characteristic averaging function; it is represented by a plurality of parameter groups, and sets a monotonic function that satisfies a plurality of predicted boundary condition groups, monotonous with respect to frequency The function and intensity characteristics, the intensity characteristics of the monotonic function satisfy the boundary condition group, and the monotonic function of the parameter group satisfies all the frequency bandwidths within a specific frequency range in which the representative intensity characteristics are closest to the fabrication conditions, and an average characteristic can be obtained The monotonic function group has the full frequency band as the characteristic function representation function, and the 12th function is the characteristic. The number performance function; the smoothing function can express the function using the 11th function averaging function and the 12th function function function, the 13th function is the smoothing function; the Uep is the smoothing characteristic obtained by the smoothing machine; Vep and { Wexp/Uep} is equal, Vep is the inherent smoothing sound quality correction feature of the headphones, the 14th function can calculate the function of Vep; the 15th function is Vep taking A as the specific fixed scale factor A*Vep as the earphone The inherently balanced sound quality correction feature; the 14th and 15th functions determine the function for smoothing the sound quality correction; the 16th function determines the function for smoothing the sound quality; Select one or use at the same time; according to the request 1, the second function of measuring the timing value of the signal generation timing, the second function of the measured timing value of the detected signal, and the series Rm conversion signal are current source signals. The fourth function of the third function and the terminal to obtain the integrated characteristics of the digital signal and the electronic signal conversion unit, the fifth function of the electric cancellation signal for generating the common line of the earphone, and the electric cancellation signal for determining the common wire of the earphone The sixth function of the coefficient, the seventh function of calculating the coupling coefficient of the left and right earphones, the tenth function of calculating the inherent sound quality correction characteristic of the earphone to be tested, and the 16th function of calculating the inherent sound quality smoothing correction characteristic of the earphone to be tested, The combination of the first, second, third, fourth, fifth, sixth, seventh, tenth, and sixteenth functions avoids the influence of different errors of the left and right electronic circuit units of the terminal, and corrects the inherent characteristics of the terminal. The effect is to remove the influence of the common wires of the left and right earphones with high precision, improve the measurement accuracy of the acoustic coupling characteristics of the left and right earphones, and obtain the inherent reproduction characteristics of the earphones. According to the regenerative characteristics inherent to the obtained earphones, the smoothing correction characteristics are used to correct the characteristics of the fine concavities and convexities, and the high-quality sound characteristics are obtained, and the method of converting the reproduction characteristics inherent to the earphones to the correction characteristics of the desired sound quality characteristics is obtained. .