When choosing a power amplifier, you must first pay attention to some of its technical indicators:

1. Input impedance: usually indicates the size of the anti-interference ability of the power amplifier, generally between 5000-15000Ω, the larger the value, the stronger the anti-interference ability;

2. Distortion degree: refers to the degree of distortion of the output signal compared with the input signal. The smaller the value, the better the quality, generally below 0.05%;

3. Signal-to-noise ratio: refers to the ratio between the music signal and the noise signal in the output signal. The larger the value, the cleaner the sound. In addition, when purchasing a power amplifier, you must make clear your purchase intentions. If you want to install a subwoofer, it is best to buy a 5-channel power amplifier. Usually 2-channel and 4-channel speakers can only drive the front and rear speakers, while the subwoofer only It can be equipped with another power amplifier, a 5-channel power amplifier can solve this problem, and the output power of the power amplifier should be greater than the rated power of the speaker as much as possible.