Hummmmmmmmmm

Finally, the basement people seem to have fixed my subwoofer.  It's nice to not have a rattle or a squeak when the bass starts thumping.

But there's still one small problem.

The subwoofer hums.

I've looked online at several things and it appears that I have a ground loop problem.  I tried a ground loop arrestor between the receiver and the amplifier for the subwoofer, but that didn't seem to fix anything at all.  I went through the steps to troubleshoot the problem and I found the source of the problem.   Any time I plug HDMI cables into my receiver (either input or output) I get a hummmmmmmmmm.

I'm kind of at a loss here.  I don't know what to do about it just yet.  I could TRY component video cable instead, but that would be expensive.  It's a 40-foot run from my projector to my receiver.  I'm going to run component video to the front (down by the projector) already, but this longer run would cost around $125 or so.  And there's no guarantee that it would even make the hum go away.

A neighbor builds and installs home theater systems for a living.  I'll have to ask him what to try next.

In the meantime, I'll just have to put up with the humming, but only during the quiet parts of movies.