Hello, I have a new 5.1 system connected to my TV. I have definitive technologies speakers (front left/right, center and 2 surrounds) and a pioneer vsx 525 AV receiver. It works fine in terms of sound production (actually it sounds great!) except there is this terrible buzz/hum sounds that comes out of the front left/right and center speakers whenever the receiver is turned on. The surrounds are fine. It is always a constant decibal level and doesn't matter what volume I have the receiver set at. I have read a lot about ground loops and while I don't entirely understand it, I have tried a few steps to see if thats the problem - disconnected the Verizon Fios box/wire, disconnected various HDMI, etc... However, nothing seems to make the buzz stop. It is present on all input settings on the receiver (Sat/Cbl, DVD, game, etc...). Any advice on what to do? Is it a problem with my receiver? My speakers? Thanks!