I have a set of infinity IL50 and a denon avr5600 receiver. I wanted to have a good karaoke system and I NEED BIG HELP. First, how can I tell how many ohm's my speakers? receiver? Second, do the ohm from the speaker has to match the receiver's? Third, would it be better to run the speaker with the Denon 5600 or should I go with a preamp and amp? What's the differences between a receiver and a preamp or amp? What will be good (amp, preamp, receiver, and what brand and how many watts and what ohm?)for a karaoke system with the IL50? Sorry for soooo many uncleared questions . THANK YOU IN ADVANCE FOR YOUR RESPONSE!