Thanks Big for the info, still a little confused though. Here is an actual picture of my breaker box, are you able to tell what is what? Not sure why the picture is sideways.. isn't that way on my computer. But the one labeled HT Lights is actually for the lights and sockets in the HT, so the subs are plugged into this. The one below it labeled basement sockets actually doesn't go to anything in the HT. Then the two below it are as they are labeled for the media closet.
Also, no satellite or cable is coming into the media closet. I have fios that runs into my HD Homerun's in my network closet, then from there all TV goes over ethernet to my HTPC's in the house. I tried disconnecting the ethernet just to make sure but that had no effect.
This is my Subwoofer cable (I also have a monoprice 50ft cable but it has the same issue), https://www.amazon.com/Mediabridge-U...rca+cable+50ft
I am beginning to think its the cable causing the problem more and more now. I have another subwoofer same make and model, with the same make cable, but only about 15 ft as it runs to the back of the room near the media cabinet and didn't need to be as long. That sub doesn't hum like the sub at the far front of my room. I noticed it says copper clad, so it does have a steel core
But with all that said, why would the subwoofer hum go away when plugged into the 20amp circuit as my other gear?
So here is where I am at as of this morning.
All AV components plugged into left socket at media cabinet. Projector is ground lifted for now as the HDMI out causes a hum in all speakers (can reduce it with ground wires connecting processor and amps.. still working on this one though but for now using a temporary fix). Both subs are plugged into the wall sockets (15amp circuit labeled HT Lights). Right now with this setup I seem to only get a hum out of the front subwoofer, it happens as soon as I plug in the RCA cable to the sub.
If it is indeed the long 50ft run of RCA cable any recommendations on a specific cable to try instead? Also what if I got a wireless rca adapter for this sub, is that even worth considering? I found this one which looks really good, even has a ground attachment point.. any thoughts on that?