I bought an RCA Sub from Radio Shack (they had 3 - I got the middle size - not sure of the model) Anyway, If the Reciever is not playing (tv,dvd) the Sub will randomly make a load skreetch (about 1/2 sec - Discharge)I can have the Sub unplugged from the Reciever and it will do it (still plugged into the wall) or the other way around (in the stero but NOT powered!) and it will do it. About every 1-3 hours. Very weird. Any Ideas? Sounds like a needle skipping on a record (if you guys know what a record is!)