E82 2008 HiFi speakers cracking / buzzing / loud static noise

[andiez.ae]

Hi guys,

Long story short, my speakers started all of a sudden to produce a strong noise.
Didn't stop with radio off / ignition off (only after a couple of minutes) and it didn't stop - now it isn't that intense but some of the speakers / tweeters don't have any sound at all. It's like playing music from a 2005 Nokia.


https://streamable.com/k0bnl

I tried replacing the amp, no change.
I tried replacing the HU, no change.

Any ideas?

Thanks,
Andreas