Influence factors of earphone sound quality
An earphone is a pronunciation system, and people's evaluation of the sound quality of earphones mainly depends on the sense of hearing, which is subjective. Different people may even have different opinions on the sound quality of the same headphones depending on their preferences.
Evaluate the technical parameters of earphones:
1.Distortion degree
Harmonic distortion, mainly cause sound hard, blast; Steady-state or transient intermodulation distortion mainly causes coarse, sharp and cloudy sound. Both of them deteriorate the sound quality. If the distortion exceeds 3%, the sound quality deteriorates obviously. The sound box of sound system distortion is the biggest, general minimum distortion also wants to exceed 1%.Phase distortion mainly causes the blurring of low frequency sound below 1kHz, and affects the sound hierarchy and image positioning of medium frequency sound.
2. Frequency response and transient response
Frequency response, refers to the gain or sensitivity of audio equipment changes with the signal frequency, with the passband width and inband uniformity (such as the frequency response of high quality power amplifier 1Hz~200kHz±ldB). The wider the bandwidth, the better the high and low frequency response: the smaller the non-uniformity, the better the frequency balance performance. Generally, the low frequency of 30Hz~150Hz makes the sound have a certain thickness foundation, the low frequency of 150Hz~500Hz makes the sound have a certain strength, the low frequency of 300Hz~500Hz sound pressure is excessively strengthened, the sound is turbidness, excessive attenuation, the sound is weak; In 500Hz~5kHz, the high frequency makes the sound have certain brightness, and when it is excessively strengthened, the sound is stiff; Excessive attenuation, sound scattered, floating; 5kHz~10kHz high frequency band makes the sound have a certain level, color; When overemphasized, the voice is sharp; Excessive attenuation, the voice is dim, muffled.
3. The signal to noise ratio
Signal-to-noise ratio, the decibel difference between the signal and the noise level, expressed in S/N or SNR (dB). The influence of noise frequency and signal intensity on human ear is different. Generally, the human ear is most sensitive to the noise of 4~8kHz, and the weak signal is more affected by the noise than the strong signal. And sound equipment is different, SNR requirements are not the same, such as Hi-Fi audio SNR > 70dB, CD machine SNR > 90dB.
4. Channel separation degree and balance
degree channel separation degree, refers to the isolation degree of stereo between different channels, with a channel signal level and the signal level difference into another channel. The bigger the difference, the better. Hi-fi sound separation is generally required to be > 50dB. Channel balance refers to the consistency of gain, frequency response and other characteristics of two channels. Otherwise, the sound track will be offset.
