The sound you are talking about is a common problem in audio equipment. Most of it is a problem with the amplifier (power amplifier). There are many reasons for it, including unreasonable circuit design and wiring, inappropriate component selection, and component quality. Due to poor grade, adjustment problems, etc., it is normal to have a slight buzz in mid-range and low-end speakers. You can suppress it by reducing the volume of the power amplifier and increasing the input signal strength to minimize the buzz. In addition, lower the treble tone to reduce the output. A higher treble level can also reduce the buzzing sound. If you can't bear the sound, it's best to replace it with a better power amplifier.