Hi All, I have a Yamaha RX-V640 receiver, with Yamaha surround speakers 5.1 (front,Cnt,Rear & Sub) & a pair of floor standing Jamo X-550 speakers. When I turn up the volume some times I hear distortion in the rear left speaker. I tried replacing the speaker with the one in the front but still there is distortion at the rear left side. All the speakers are 6 ohms (Yamaha+Jamo). Is this a speaker issue or a Receiver issue. I am thinking of upgrading my rear speakers with Yamaha P-60 6 ohms model (Rear + Center) But I am not sure will this solve the problem. Regards, Mazhar