I got a great deal on a lsi c center channel from Polk, not realizing it is rated as a 4 ohm speaker. I'm driving it with a Onkyo TX-SR 608, which appears to be tested for continuous 6 ohm use but the specs say nothing about 4 ohm. Should I see this as a problem? Am I asking for trouble? Or is it a non issue? I sure don't want to fry my avr on it's first use.