To analyze the usage, there are a few reasons explain why the speakers emit buzz sound or noise:

1. Speaker is a passive component, and the drive circuit decides the sound. Therefore, giving the correct power and waveform to the speaker is the basic request.
The too large power will lead to the too big amplitude of the diaphragm. The slight problem is distortion, but the serious problem is that the diaphragm might hit the mechanism or the magnet and cause the buzz sound. The basic waveform to drive the speaker is sine wave, if we give square wave or other waves, the efficiency of the speaker will reduce and easily get heated, the buzz sound may happen as a matter of course.

2. The enclosure design of the product will also affect the quality of the sound. The well designed enclosure can improve the frequency response curve of the speaker.
The area of sound apertures of the enclosure at least request over 1/8 area of the surface. We need to keep enough vibration space between the case and the diaphragm to avoid the diaphragm hitting the case when it works and emits the noise.