I just got the new B&K AVR-507 receiver which is awesome " so many things i have no clue yet how to use". Anyway it has worked fine for the last three days and all of a sudden when i put it in sleep mode my RIGHT front speaker makes a wind type sound. When you put your ear up to it, it sounds like like a windstorm. It only does it on that one channel and when you turn the power back on it works fine. Anyone have a clue what it could be ?