How to match professional audio and amplifiers is better? Study


In theory, a professional amplifier rated power is 400W resistance 4Ω, four speakers, and the rated power is 100W resistance 4Ω. The four speakers are connected in series and then connected, the total impedance remains unchanged, or 4Ω, but the total rated power can reach 400W. From the perspective of impedance matching, the speaker parallel or chanting can save the number of power amplifiers and save funds. But in actual operation, the theoretical knowledge may not be able to do it.

The amplifier and speakers are connected with the four -factor power amplifier and speakers to pay attention to the warm and warm, and the soft and hardness to achieve the neutrality of the whole set of equipment restore. This is only artistic. However, the elements considers from the technical perspective are:

First, power matching.

Second, the power reserve volume matching.

Third, impedance matching.

Fourth, matching coefficients.

If we recognize the above four points during the connection, the performance of the equipment used can be played larger and most fully exerted.

Power matching

In order to meet the requirements of high -fidelity listening, the rated power should be determined according to better listening sound pressure. We all feel this: the volume is hour, weak sound, thin, dynamic, no gloss, low frequency lack of lack, poor plumpness, the sound seems to shrink inside. When the volume is appropriate, the sound is natural, clear, round, soft and full, powerful, and dynamic. However, when the volume is too large, the sound is hard, rough, and has a tie. Therefore, the repeat pressure level has a greater relationship with the quality of the sound. It stipulates that the sound pressure level of the sound zone is better at 80 ~ 85DB (A margin). The rated power of the speaker and the rated power of the amplifier.

Power reserve volume matching

Speaker: In order to withstand the impact of the strong pulse of the sudden pulse in the program signal, it is not damaged or distorted. Here is an empirical value for reference: the selected speaker nominal rated power should be three times the power of the manager theory calculation.

Portom amplifier: Compared with the amplifier of electronic tube power amplifiers, the power reserves required are different. This is because: the overload curve of the electronic pipe amplifier is relatively smooth. For the high -quality music signal of the lotus, the electronic pipe power amplifier does not obviously produce the phenomenon of cutting waves, but just turns the high quality of the peak. This is the flexible peak we often call. After the transistor is placed in the load point, the non -linear distortion is increased rapidly, and the signal is severely cut. It does not turn the peak round but cut it neatly. Some people use resistance, inductance, and capacitance composite impedance simulation speakers to test the actual output capacity of several high -quality transistors. The results show that when the load is shifted, there is an amplifier named 100W, and the actual output power is only 5W when the distortion is 1%! The selection of the reserves of the transistor power amplifier:

High -fidelity power amplifier: 10 times

Civilian high -quality power amplifier: 6-7 times times


Civil mid -range power amplifier: 3 ~ 4 times

The electronic power amplifier can be larger than the above -mentioned ratio.

With a reasonable desktop HIFI system

For the system’s average sound pressure level and higher sound pressure level, there should be a large amount of surplus level, and it should be dependent on the content and working environment of the broadcast program. This redundant amount is 10DB. For modern pop music, busudi and other music, you need to leave 20 ~ 25DB redundancy, so that the audio system can work safely and stably.


It refers to the rated output impedance of the amplifier, which should be consistent with the rated impedance of the speaker. At this time, the amplifier is in a better design load line, so it can give a large unpleasant power. If the rated impedance of the speaker is greater than the rated output impedance of the amplifier, the actual output power of the amplifier will be less than the rated output power. If the rated impedance of the speaker is less than the rated output impedance of the amplifier, the audio system can work, but the amplifier is risk of overloading. It is required to have comprehensive overcurrent protection measures to solve it. For electronic pipe amplifiers, the impedance matching requirements are more stringent.


The matching coefficient of the damping coefficient

The damping coefficient KD is defined as: KD = power amplifier rated output impedance (equal to speaker rated impedance)/amplifier output internal resistance. Since the internal resistance of the amplifier output has actually become the magnetic device of the speaker, the KD value determines the voltage amount of the speaker. The larger the KD value, the heavier the engine is. Of course, the KD value of the amplifier is not bigger, the better. The KD value is too heavy to make the speaker molecurant too heavy, so that the establishment of the front edge of the pulse increases, and the transient response indicators are reduced. Therefore, when selecting the amplifier, we should not pursue a large KD value.