I have 2 Polk RT20P tower speakers. I have a Harman/Kardon AVR1650. The H/K is brand new. I hooked both speakers up and it was working perfect. Then the receiver shuts off and wouldn't come back on. Went into protect mode. I unhooked the speakers and it turned back on no problem. So I hooked up one speaker and it works fine. Tried hooking up the other and it shuts off again. I hooked them up individually to make sure each speaker was still functioning. They both are fine. So basically if I have one hooked up, the receiver works, if I try hooking both up, the receiver shuts off. I bought new speaker wire (12 gauge) and a new surge protector. Any suggestions?