KR20050091192A - Method and the device that measure specisl quality of speaker - Google Patents

Abstract

The present invention relates to a method for measuring the characteristics of a speaker and the structure of the device, the impedance of the speaker to output the sound of the audible frequency band in response to the applied electrical signal, Sound Pressure Level (SPL), poor sound quality, etc. In the speaker characteristic measuring instrument which measures the speaker characteristic of

When the test signal generating means 10 for applying a test electrical signal to the speaker to be tested and the electrical signal generated by the test signal generating means 10 generates sound through the speaker, the sound generated from the speaker Sound detection / measurement means 20 for detecting and measuring a signal detected by a microphone by detecting sound, and arithmetic means 30 for calculating or storing data of the test signal generation means 20 and signal sound detection / measurement portion 30. And a display means 40 for displaying the value calculated or stored in the calculation means 30, and driving the speaker using a sweep oscillator with a frequency ranging from 20HZ to 20KHZ, The sound generated from the speaker is sensed through a microphone, and a FFT (Fast Fourier Transfor) is used to detect a bad sound or a bad sound for each frequency band of the detected sound. m) Detecting, data-forming, and defective coefficient (sound quality) by using an analysis unit, and also data-based, conventionally measured by using a variety of measuring devices can measure all the speaker characteristics with a single measuring instrument of the present invention, reliable quality control And it provides a speaker characteristic measuring instrument that can guarantee quality, and has an effect that helps a lot in productivity and reproducibility.

Description

Method and the device that measure specisl quality of speaker

The present invention relates to a method for measuring the characteristics of a speaker for measuring the characteristics of the speaker, and a measuring device for driving the speaker using a sweep oscillator with a frequency within 20HZ ~ 20KHZ, the sound generated from the speaker microphone It detects the sound through the FFT (Fast Fourier Transform) analysis unit for each of the frequency bands of the detected sound through the FFT (Fast Fourier Transform) analysis, and the data is conventionally used a number of measuring devices It is effective to measure the characteristics of all speakers with a single measuring instrument, and also to measure and substitute objective failure coefficients for the sound quality of speakers, so that quality control and quality assurance can be relied on. It's about a speaker characterization instrument that has a lot of benefits for productivity and reproducibility.

In general, the principle of the speaker is to tap the drum with a drumstick and the surface of the leather drum begins to vibrate. Due to this vibration, the air around the drum also begins to vibrate, and the vibration of the air propagates to the surroundings and can be heard through the human ear.

The medium for transmitting the vibration of the drum surface to the human ear is air, and the medium for transmitting sound can be transmitted not only through a gas such as air but also through a liquid such as water and a solid such as wood.

Eventually, we can say that the vibration of an object makes a sound. The sound of the object is shortened by tapping on the tree, but the sound continues for a long time by tapping on the drum.

In order to generate the sound, the material may be vibrated, but if it is slowly vibrated, low sound is generated. On the contrary, if it is vibrated quickly, high sound is generated. Use the principle to generate sound.

The general configuration of such a speaker is as follows.

The signal input to the speaker is an electric signal having sound information. The electric signal includes all information related to the sound, such as the loudness and the frequency, and is input to the electromagnet.

 In this case, the direction of the N pole and S pole and the strength of the magnet are different according to this signal.At the rear of the electromagnet, a permanent magnet with a constant strength of the magnet is located. In addition to pushing and pulling, depending on the magnet strength of the electromagnet, the pushing and pulling force may increase or decrease.

One end of the electromagnet is attached to a round cone in the center of the speaker, and the cone moves along with the movement of the electromagnet, eventually moving the cone attached to the cone.

Such a speaker is not only manufactured in accordance with its intended use but also differs in size and shape, and its characteristics are also different.

The characteristics of the speaker include a resonance frequency band, an impedance value, an output sound pressure level (SPL), a sound quality, etc., which is directly related to the quality of the speaker, and is also a measure of the quality of the speaker.

As a method of screening out defective products that may occur during the manufacture of a loudspeaker, conventionally, a resonant frequency measurement, an impedance measurement, a polarity measurement, a sound pressure level (SPL) measurement, etc. have been measured with each measuring instrument. It has been tested, which has been measuring each characteristic with each measuring instrument was consumed a lot of measurement time, not only low productivity, but also had a problem that is difficult to manage due to irrational inspection.

In addition, in the related art, in measuring sound quality, which is one of the characteristics of a speaker, it is possible only by human hearing. As a result, there is no objective criterion of the speaker, which makes it difficult to control the speaker defect factor (sound quality) for sound quality. Occurred.

The present invention has been made in view of the above-mentioned problems occurring when measuring the characteristics of the conventional speaker as described above, driving the speaker using a sweep oscillator (sweep oscillator) of the frequency within 20HZ ~ 20KHZ, The generated sound is detected through a microphone, and a bad sound or a strange sound is detected for each frequency band of the detected sound using an FFT (Fast Fourier Transform) analysis unit, and data is conventionally used. It is possible to measure the characteristics of all speakers by using a single measuring instrument, and to measure and substitute objective failure coefficients for the sound quality of the speaker by using multiple measuring devices. It is an object of the present invention to provide a speaker characteristic measuring instrument that helps a lot in productivity and reproducibility.

The method and apparatus for measuring the characteristics of the speaker of the present invention for achieving the above object are as follows.

In the speaker characteristic measuring instrument for measuring the characteristics of the speaker, such as impedance, output pressure level (SPL) of the speaker that receives the applied electrical signal and outputs sound in the audible frequency band,

Test signal generating means (10) for applying a test electrical signal to a speaker to be tested;

When the electrical signal generated by the test signal generating means 10 generates a sound through the speaker, the signal sound detection / measurement means for detecting and measuring the sound generated by the speaker by detecting the sound generated by the speaker through the microphone. 20;

Calculation means (30) for calculating or storing data of the test signal generation means (20) and the signal detection / measurement unit;

The display means 40 for displaying the value or the value calculated or stored in the calculation means 30, the test signal generating means 10,

A sweep sine wave generator 110 for applying an analog test sound source signal to the speaker 170;

A voltage adjusting unit 120 controlling a voltage applied to the speaker;

A volume unit 130 configured to attenuate low voltage noise by combining with the electrical signal of the sine wave oscillator 110 and the power applied from the voltage adjusting unit;

An audio power amplifier 140 for amplifying the electrical signal output from the volume unit 130;

An impedance detector (150) for detecting current by detecting a current with a shunt included in the sound source amplifier 140 and calculating the output voltage;

A lowest resonant frequency (Fo) detection unit 160 for detecting a resonant frequency by combining real-time impedance for each sweep frequency applied by the sound source amplifier 140;

The speaker 170 is configured to output the sound by receiving the electric signal amplified by the sound source amplification unit 140, and the signal sound detecting / measuring means 20 includes a microphone for detecting the sound generated by the speaker 170 ( 210;

A sensing signal amplifier 220 for amplifying the electrical signal sensed by the microphone 210;

An output sound pressure level (SPL) detector 230 for measuring and displaying a sound pressure of the electrical signal amplified by the detection signal amplifier 220;

A fast fourier transform (FFT) analyzer 240 for analyzing sound quality from the electric signal amplified by the sense signal amplifier 220;

A sound signal amplifier 250 for amplifying the electrical signal amplified by the input signal amplifier into a sound signal;

The headphone 260 is configured so that the sound signal amplified by the sound signal amplification unit 250 can be audibly listened to, and a 16-bit 20HZ ~ 10KHZ sweep sinusoidal signal is tested through a connected analog sweep oscillator. When a signal is applied to a speaker, a test sound is generated from the speaker to be tested. The test sound generated from the speaker is detected through a microphone, and a gain value is detected by detecting a frequency component of 10 KHZ or more and dataizing the value. When measuring the speaker sound quality with the control and setting of, or applying 16-bit 20HZ ~ 20KHZ sweeping sinusoidal signal to the speaker to be tested through the connected analog sweep oscillator, a test sound is generated from the speaker to be tested. The test sound generated by the speaker is detected through a microphone and sweeped in real time. By detecting frequency components other than frequency components and making these values data, speaker quality can be measured by adjusting and setting gain values, as well as measuring resonance frequency, impedance measurement, polarity measurement, and output pressure level. Integrated measurement of SPL measurements

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1a is a block diagram showing the overall configuration of the speaker characteristic measuring instrument according to the invention, Figure 1b is a block diagram showing a detailed configuration of the speaker characteristic measuring instrument according to the present invention, Figure 2 is a speaker characteristic measuring instrument according to the present invention FIG. 3 is a diagram showing an example of measuring the characteristics of a speaker, and FIG. 3 is an exemplary table showing an example of a reference setting program of a speaker characteristic measuring instrument according to the present invention, and FIG. 4 shows the result measured by the speaker characteristic measuring apparatus according to the present invention. The speaker measurement result table is displayed.

Referring to the test signal generating means of the speaker characteristic measuring instrument according to the present invention as shown in Figure 1a and 1b, the analog sweep oscilator is controlled by the software of the computer, and output through the sound card of the computer do. At this time, when outputting an analog sweep signal at a low voltage, an analog sweep signal including a lot of noise components of the computer is generated. The output of the sound card installed in the computer is maximized to remove the noise. By controlling the voltage control unit of the I / O card to control and output the DC voltage of 0 ~ 10V, the amplitude modulation circuit (AM modulation) for modulating the amplitude of the signal and the DC voltage is controlled to gain The controller adjusts the volume to remove the noise component, amplifies the signal from the audio power amplifier, and applies the signal to the speaker to be tested.

At this time, when a sine within 20HZ ~ 20KHZ amplified by the audio power amplifier is applied to the speaker to be tested, a current flowing through a resistor shunt is detected and a voltage supplied to the speaker is detected. The impedance of the speaker may be measured by computing the current and the computer, which is a substitution means.

And

Because of

The impedance of the speaker can be obtained by induction.

V: Output voltage of the sound source output unit Vsp: Voltage applied to the speaker

Vr: Voltage applied to the classifier R: Resistance of the classifier

Rsp: Speaker Impedance

Therefore, if any one frequency is selected within 20HZ ~ 20KHZ, the impedance of the frequency set by the impedance detection unit is displayed on the screen through the display means, and the pass / fail determination is made by comparing whether it is within the preset range.

If the speaker impedance is continuously measured in real time within 20HZ ~ 20KHZ and displayed on the screen through a display means, the impedance change for each frequency of the speaker to be tested can be seen, and the impedance at the lowest resonant frequency Fo is detected. The resonance point is found by changing the initial resonance point, and the pass / fail decision is made by comparing with the area already set. At this time, the pass / fail range of the output sound pressure level (SPL) may be set in units of 0.1 dB.

In addition, looking at the signal sound detection and measurement means, by detecting the connection sound generated in each frequency band within 20HZ ~ 20KHZ generated from the output sound of the speaker through the microphone, and applies the detected signal to the detection signal amplifier. The sound pressure level (SPL) displayed on the screen is displayed on the screen through a display means, and the signal applied to the detection signal amplification unit is preset in the computer, which is the computing means, and compared with the data value stored in the database of the computer. By calculating, the pass / fail determination of the speaker output sound pressure level (SPL) to be tested is made and displayed on the screen.

When the signal amplified by the detection signal amplification unit is applied to an FFT analyzer (Fast Fourier Transform), a frequency component of 10 KHZ or more is detected and the value is converted into data to adjust and set a gain. By measuring the sound quality or detecting frequency components other than the frequency components that are sweeped in real time and making data into these values, the speaker sound quality is measured by adjusting and setting the gain, and calculating the pass / fail determination. The comparison is performed through the means, and displayed on the screen through the display means.

In addition, in order to improve the objective and subjective measurement reliability of the present invention, the signal generated by the detection signal amplification unit is applied to the sound signal amplification unit and amplified by reproducing the connection sound generated in the speaker to be tested with headphones, the present invention is a calculation means The measurement reliability was improved by allowing automatic pass / fail inspection and the pass / fail judgment by the inspector's hearing.

As an exemplary embodiment of the present invention, as shown in FIG. 2, the microphone is installed on the lower side of the jig in which the sound absorbing material for removing the reflection sound is installed inside the speaker to be tested, and the speaker to be tested is hypothesized on the upper side.

And, as shown in FIG. 3, the reference item setting and the measurement item of the speaker to be tested can be controlled by a program. The configuration includes the product information (a), the upper and lower setting (b), and the reference data for the agreement of the SPL. (c), preview (d), SPL inspection frequency range (e), sweep setting (f), Fo / Ze setting (g), inspection (h), voltage setting (i) and so on.

The product information (a) is to input the information of the speaker to be tested, that is, the model name, lot number, serial number, etc., or sequentially assigned, the upper and lower setting (b) is the sound range of the speaker to be tested Setting performs the function of setting in dB unit.

And, the reference data (c) has a function of loading data of the speaker characteristics already input or storing data of the tested speakers, and when setting the output sound pressure level in the SPL test frequency range (e), the preview In (d), the set output sound pressure level is displayed in a graph.

The sweep setting (f) performs a sweep method, a sweep time, a start frequency, an end frequency, a sweep frequency, and the like, and the Fo / Ze setting (f) sets a resonance frequency band and a Ze frequency band. The function (h) performs a function of setting a characteristic item of the speaker to be tested, and the voltage setting (i) performs a function of setting an applied voltage to the speaker to be tested.

Setting the test item setting and range of the speaker to be tested as described above, and testing the speaker, the characteristics of the speaker are displayed graphically as shown in Figs. 4a and 4b, the pass and fail of the characteristics It is determined and displayed on the screen.

As described above, according to the speaker characteristic test method and the measuring apparatus of the present invention, a speaker is driven using a sweep oscillator with a frequency within 20HZ ~ 20KHZ, and the sound generated from the speaker is transmitted through the microphone. Detect bad sound or audible sound for each frequency band of the detected sound using an FFT analysis unit, and convert the data into a single measuring instrument that is conventionally measured using several measuring devices. It has the effect of being able to measure the characteristics of the product, and it is also possible to measure and substitute objective defect coefficients for the sound quality of the speaker, so that it can reliably control quality and guarantee quality, and it is very helpful for productivity and reproducibility. Have

Figure 1a is a block diagram showing the overall configuration of a speaker characteristic measuring instrument according to the present invention.

Figure 1b is a block diagram showing a detailed configuration of a speaker characteristic measuring instrument according to the present invention.

Figure 2 is a block diagram showing the concept of measuring the characteristics of the speaker by the speaker characteristic measuring instrument according to the present invention.

Figure 3 is an exemplary table showing an example of a reference setting program of the speaker characteristic measuring instrument according to the present invention.

4 is a speaker measurement result table showing the results measured by the speaker characteristic measuring instrument according to the present invention.

※ Explanation of symbols about main part of drawing ※

           10: signaling means 20: beep detection / measurement means

           30: arithmetic means 40: display means

           110: sine sine wave oscillator 120: voltage regulator

           130: volume unit 140: sound source amplification unit

           150: impedance detector 160: resonant frequency detector

           170: speaker 210: microphone

           220: detection signal amplifier 230: output sound pressure level detector

           240: FFT analyzer 250: sound signal amplifier

           260: headphones

Claims (4)

In the method of checking the characteristics of a speaker, when a signal is applied to a speaker to be tested by a sweeping sine wave signal of 16 bits of 20HZ ~ 10KHZ through a connected analog sweep oscillator, a test sound is output from the speaker to be tested. In this case, the test sound generated from the speaker is detected through a microphone, and the speaker sound quality is measured by adjusting and setting a gain value by detecting a frequency component of 10 KHZ or more and dataizing the value. Speaker characteristic instrument. In the method for checking the characteristics of a speaker, a test sound is generated from a speaker to be tested when a 16-bit 20SZ to 20KHZ sweeping sinusoidal signal is applied to a speaker to be tested through a connected analog sweep oscillator. It detects the test sound generated from the speaker through a microphone, and detects a frequency component other than the frequency component that is sweeped in real time and makes a data of this value to adjust and set the gain value. Speaker characteristic instrument, characterized in that for measuring. In the speaker characteristic measuring instrument for measuring the characteristics of the speaker, such as impedance, output pressure level (SPL) of the speaker that receives the applied electrical signal and outputs sound in the audible frequency band, Test signal generating means (10) for applying a test electrical signal to a speaker to be tested; When the electrical signal generated by the test signal generating means 10 generates a sound through the speaker, the signal sound detection / measurement means for detecting and measuring the sound generated by the speaker by detecting the sound generated by the speaker through the microphone. 20; Calculation means (30) for calculating or storing data of the test signal generation means (20) and the signal detection / measurement unit; And a display means (40) for displaying the numerical value calculated or stored in the calculation means (30). The method of claim 3, wherein the test signal generating means 10, A sweep sine wave generator 110 for applying an analog test sound source signal to the speaker 170; A voltage adjusting unit 120 controlling a voltage applied to the speaker; A volume unit 130 configured to attenuate low voltage noise by combining with the electrical signal of the sine wave oscillator 110 and the power applied from the voltage adjusting unit; An audio power amplifier 140 for amplifying the electrical signal output from the volume unit 130; An impedance detector (150) for detecting current by detecting a current with a shunt included in the sound source amplifier 140 and calculating the output voltage; A lowest resonant frequency (Fo) detection unit 160 for detecting a resonant frequency by combining real-time impedance for each sweep frequency applied by the sound source amplifier 140; The speaker 170 is configured to output the sound by receiving the electric signal amplified by the sound source amplification unit 140, and the signal sound detecting / measuring means 20 includes a microphone for detecting the sound generated by the speaker 170 ( 210; A detection signal amplifier 220 for amplifying the electrical signal detected by the microphone 210; An output sound pressure level (SPL) detector 230 for measuring and displaying a sound pressure of the electrical signal amplified by the detection signal amplifier 220; A fast fourier transform (FFT) analyzer 240 for analyzing sound quality from the electric signal amplified by the sense signal amplifier 220; A sound signal amplifier 250 for amplifying the electrical signal amplified by the input signal amplifier into a sound signal; Speaker characteristics measuring instrument, characterized in that the headphone 260 is configured to listen to the sound signal amplified by the sound signal amplification unit 250 in an audible manner.