I did a troubleshoot for a guy this morning who has this receiver, Polk rt1000p towers, m series rears, and cs center.

At the receiver and at most of the speakers, they meter about 4-5 ohms and seem to work. The problem is his Yamaha has recently started to shut off. I told him I thought it was the load on the receiver (being not the 6-8 ohm range) and it had just finally started to get unhappy and quit on him.

Looking at all the Polk manuals, they all basically said "works with 8 ohm speaker output" or something to that effect.....but no real impedance rating on the speaker itself....another strange thing, I thought.

He will probably buy new speakers and re-purpose the old, but I wanted to pick brains first.

Thanks!