thanks Atdamico. Yea the "hum" is coming from the sub/amp?, is nor really loud,but I can still hear it, maybe is normal. aso on the back of the speakers there are two rca inputs, do I suppose two use those? maybe to the preouts?, but I already have a sub hooked up to it. one of the RCA says 'normal' and the other says 'direct', right now I have them hooked up via wires, just like anyother sapeaker. Am I missing something?