I have a HK system in my Mini with a boost head unit(?)

The other day it started making a really loud buzzing noise from the rear speakers, you can still hear the music in the background but the buzzing noise is really loud. The front speakers are fine.

Any ideas people?

Let it rest. If it continues, then its probably the amp. A common problem.

Thanks for the reply docrc.

I took the amp out of the car, opened it up and got a hair dryer on it for a minute, plugged it back in and guess what.... It works!!