Why periodically beep speakers?

Question

Electronics

Acoustics Sven sps 820, works for about a month.
Here is a video with a squeak , squeak at 4 and 24 seconds. It may not be so audible on the recording, but in real life it is a little louder and terribly annoying. What is it in general and how to treat?
upd sometimes the squeak disappears for hours, but then it reappears when I turn it
off from the computer - they don't squeak. I connect to the computer - they squeak even with the sound turned off in Windows.

Answer 1

First you need to figure out who is the source of the squeak, speakers or computer .... try connecting the speakers to another sound source (TV, laptop, tablet, phone, etc.) if there is no squeak, then the computer is to blame ....
If the computer is to blame - then there can be many reasons ....
Here are a few reasons:
1. Connect to other connectors
2. Computer power supply (swap with a friend for a while to check the power source)
3. OS (install ubuntu at your leisure, then return Windows)
4. Replace the motherboard (this should be tried first of all, but finding a replacement mother for a while is problematic)

Answer 2

Pickups from the body and sound card, poor screening....
the first thing that came to mind.

Answer 3

playing sound from a microphone into speakers can lead to a "beep"

Answer 4

squeaked microlab (microlab), started for no apparent reason, you can call it self-excitation, the frequency was more than a kilohertz (otherwise some buzz is called a squeak). So, the reason was in the glue, which, during assembly, stained some components of the amplifier board.