Blackhawk20

I have a 2001 ML55. The problem I have is with the Bose sound system.It started out with going over a speed hump I get a crackling/buzz come through the speakers. Then the system went dead, except that I still get a buzz through the system even when it is turned off. I thought it was the command centre originally, but now i am not so sure, seems more amplifier to me.
Any suggestions? I think I found the amp next to the computer just behind the main fuse box.
Has anyone had similar problems?

Regards from Australia
John