The speaker in question was paid for a few euros online:

and has this noise during playback (often starting just a few seconds after normal use):
https://jmp.sh/qB5qZXsU

Where can this noise come from?
From the antenna?
From the power supply? (battery)
Maybe Bluetooth operates on the 2.4Ghz band and can interfere with home wifi?
Is there any way to remove it?

 

What is powering it? What is sending the signal? Does it work with another BT speaker?

 

What is powering it? What is sending the signal? Does it work with another BT speaker?

The pink battery powers the circuit and the signal is sent by the BT of my smartphone.
It is possible to recharge the battery with usb 5V

 

Does it work with another BT speaker?

I don't understand what you mean..
You mean send BT from another smartphone?

 

Does you phone send the same audio to a different BT speaker correctly?

Does a different phone work correctly with this speaker?

Does a different music source on this phone work correctly?

There is some component misbehaving. You need to find out which one. It is not RF interference. That would cause an entirely different symptom.

 

Does you phone send the same audio to a different BT speaker correctly?

yes

Does a different phone work correctly with this speaker?

no

Does a different music source on this phone work correctly?

yes

 

There is some component misbehaving. You need to find out which one. It is not RF interference. That would cause an entirely different symptom.

Any advice? Where would you start and how?

Thank you.

 

The BT speaker s defective. Hopefully you can get a refund.

 

The BT speaker s defective. Hopefully you can get a refund.

It is likely, however, at first it was going and only after a while did it stop working.

 

You get what you pay for.