Hi. Did you try replacing the screw in the subwoofer after you disconnected the TV cable? I had a ground loop problem with my EP500 caused by the cable TV. I ended up buying a Jensen Isomax SUB-1RR between my reciever and the sub. It solved the problem. The isomax was about $100. This fix should work no matter where the ground loop is. You can also get a transformer to go between the TV cable and the cable box which is cheaper. I was afraid of messing with the quality of my TV reception so I went for the SUB-1RR.
My first post.
