stereo probem

I got a new 600 watt home theattre system for x-mas and hooked it up and it worked fine for about a month.now the subwoofer humms very loudly when activated. i swithched the left front speaker with my subwoofer and the left front started humming. then i unpugged my vcr, i still had humming,unplugged my tv still had humming, then i unplugged my digital cabal box and the humming finnally stopped.eveidently its my ditital cable box. i moved my subwoffer to the fartest corner away from my tv and it still humms with the cable box hooked up. what do i have to do to keep my ditatal cable box and run my new home theatre at the same time. ive already tied all the wires and cables together.? will it do me any good to insulate around these appliances.? any help would help

 

sounds like ground loop hum. I'm not totally up on the fixes for this problem, but I believe that the cable coming into your house isn't grounded properly. Could try calling the cable co to check that out, or get a ground loop isolator.

 

You may have a bad patch cable comming from the Cable box to your reciever. Swap the cord and see if that corrects it. jonny