I bought a new active speaker but the current sound was very loud when I got it back. It was not there when I tried it. It was just in my room and not elsewhere?

This problem can be solved in three aspects:

1: When other electrical appliances are turned on, the speaker responds. It means that the sensitivity of your speaker is quite high. You might as well replace its audio cable with a shielded audio cable, which costs about 10 yuan. It is best to cover the power amplifier part (preamp) in the machine with a metal cover. Ground or earth terminal.

2: There is a popping sound when the speaker is turned on. The solution is to replace the switch with a bootstrap switch circuit, or turn on the speaker to minimize the sound first.

3: There is a buzzing sound. That means the capacitor used to remove the AC component in the rectifier part of your power supply is broken, or the inductor coil is short-circuited. Generally, it is the first capacitor in the rectified part, which is connected in parallel to the positive and negative ends. Just buy another one and replace it according to the logo above (do not connect the positive and negative poles of the capacitor reversely). Another possibility is that the audio cable of your signal source is not shielded, causing the electromagnetic waves in the space to interfere with the signal source. The amplifier amplifies this part of the clutter and creates a buzzing sound. Just replace the first one with a shielded wire.

If you don’t know how to do it yourself, the easiest way is: 1. Buy a shielded signal cable. 2. Just buy a power supply with rectifier and replace it directly. But the cost is higher than repairing it yourself.