"xrongor" wrote in message news:HeDYb.212095$U%5.1223717@attbi_s03...
When the receiver is
powered on, the hum's volume increases more. The receiver and the
subwoofer are configured to plug into different grounded outlets.
Both outlets are properly wired.

(snip)

but i would first try this. disconnect any cable tv sources you have and
see if it goes away.

A cable TV connection somewhere in the system (such as connected to
your TV or VCR) is often the problem, although other posts in this
thread may also be useful.

If you have cable TV, try disconnecting the cable from your system. If
that solves the problem, then go to www.google.com and search web and
newsgroups for fixes. Search terms such as:

cable TV
hum
ground loop
subwoofer

A few searches will probably lead you to more info and simple fixes.
Fixes for this sort of problem are often cheap or free.

If the cable TV is the problem, also call cable TV company and ask for
advice.

If you can't fix the problem, here's another resource:

rec.audio.tech

But I think your problem should be easy to fix, although it may
involve a little trial and error and plugging in your gear a few
different ways until you find something that makes the hum go away.

if that doesnt work, do what robert bass said. either
isolate the ground plug, or put em both in the same exact outlet and see
what happens. you also didnt say if the different outlets are on the same
circuit..

lastly, before taking it back to the shop, take it down to bare bones, and i
mean bare. just plug in the sub, and use the radio on the receiver and
disconnect everything else. if this fixes it, bring it up one at a time
until the hum returns.

randy