Nowadays, the speakers on the market are more than a thousand expensive, and you can buy them at a price of 30 yuan. So what kind of speakers are really good speakers? Next, I will talk to you about the relevant performance indicators of the speakers, hoping that these contents can provide you with some references when buying speakers.
1. Frequency Range
The full name of frequency response range is called frequency range and frequency response. The former refers to the range between the lowest effective playback frequency and the highest effective playback frequency of the speaker system; the latter refers to the sound pressure generated by the speaker when a constant voltage output audio signal is connected to the system. The phenomenon of increasing or attenuating, and the phase changing with frequency. This correlation between sound pressure and phase and frequency is called frequency response, in decibels (dB). The curves of sound pressure and phase lag with frequency are called "amplitude-frequency characteristics" and "phase-frequency characteristics", collectively called "frequency characteristics". This is an important indicator for evaluating the performance of speakers. It is directly related to the performance and price of the speakers. The smaller the decibel value, the flatter the speaker's frequency response curve, the smaller the distortion, and the higher the performance. For example, the frequency response of a speaker is 60Hz~18kHz+/-3dB. These two concepts are sometimes indistinguishable and are called frequency response. Theoretically speaking, the harmonic components that make up the sound are very complicated. It is not that the wider the frequency range, the better the sound, but this is basically correct for the middle and low-end multimedia speakers. The current speaker manufacturers generally label the system frequency response too large, and the high frequency part is not too bad, but the label on the bass end is extremely unreal, so I warn you that you must listen to the low frequency sound, and don’t believe it lightly. The value on the leaflet.
This indicator refers to the sound pressure level measured one meter in front of the vertical axis of the speaker plane when a 1W/1kHz signal is input to the speaker input terminal. The unit of sensitivity is decibel (dB). For every 3dB difference in the sensitivity of the speaker, the output sound pressure will double. The sensitivity of ordinary speakers is in the range of 85-90dB, below 85dB is low sensitivity, and above 90dB is high sensitivity, and the sensitivity of multimedia speakers is usually slightly lower.
The indicator is simpler, it is to feel how powerful the sound from the speaker can be. According to international standards, there are two labeling methods for power: rated power and maximum withstand power (instant power or peak power PMPO). The rated power refers to the maximum undistorted power that the speaker can emit within the rated frequency range of a continuous analog signal with a prescribed waveform, and the maximum withstand power is the maximum electrical power without any damage to the speaker. In order to cater to consumers' psychology, businesses usually set a large standard for music power, so the rated power shall prevail when purchasing multimedia speakers. The maximum power of the speaker is mainly determined by the chip power of the power amplifier, and also has a lot to do with the power transformer. You can roughly know the weight of the transformer by taking a look at the weight difference between the main and auxiliary speakers, usually the heavier the greater the power. However, the power of the speaker is not the bigger the better, and the application is the best. For an ordinary home user's room of about 20 square meters, the real power of 50W is enough, and there is no need to pursue high power too much.
The definition of the distortion of the speaker is basically the same as the distortion of the amplifier. The difference is that the input of the amplifier is an electric signal, and the output is still an electric signal, while the input of the speaker is an electric signal, and the output is a sound wave signal. Therefore, the distortion of the speaker refers to the distortion of the electro-acoustic signal conversion. The allowable range of sound wave distortion is within 10%, and the general human ear is not sensitive to distortion within 5%. It is best not to buy speakers with distortion greater than 5%.
5. Signal-to-noise ratio
This index refers to the ratio of the normal sound signal and the noise signal played back by the speaker. The signal-to-noise ratio is low, and the noise is serious when a small signal is input. The sound in the entire sound range becomes turbid and unclear. I don't know what sound is being sent, which seriously affects the sound quality. Speakers with a signal-to-noise ratio below 80dB (including subwoofers below 60dB) are recommended not to be purchased.
This index refers to the ratio of the voltage to the current of the input signal. The input impedance of a speaker is generally divided into two types: high impedance and low impedance. Generally, high impedance is higher than 16 ohms, and low impedance is lower than 8 ohms. The standard impedance of speakers is 8 ohms. The nominal impedance of speakers on the market is 4 ohms, 5 ohms, 6 ohms, 8 ohms, 16 ohms, etc. Although this indicator has nothing to do with the performance of the speakers, it is best not to buy low-impedance speakers. The recommended value is standard. This is because when the power amplifier and output power are the same, a low-impedance speaker can obtain a larger output power, but if the impedance is too low, it will cause underdamping and bass degradation.
7. Sound technology
Hardware 3D sound effect technologies are now more common, such as SRS, APX, Q-SOUND and Virtaul Dolby. Although they implement different methods, they can all make people feel obvious three-dimensional effects. Among them, the first one is the most common. common. They are all applied to the Extended Stereo theory, which is the additional processing of the sound signal through the circuit, so that the listener feels that the sound direction is extended to the outside of the two speakers, so as to expand the sound and give people a sense of space and harmony. The three-dimensional effect produces a wider stereo effect. In addition, there are two sound enhancement technologies: active electromechanical servo technology and BBE high-definition plateau sound reproduction system technology, which also have a certain effect on improving sound quality.