I recently purchased a YAMAHA RX-V1500 to power my 25yr old YAMAHA NS690-II's that will be used as the mains while I build a home theater system. I've since added an ASCEND CMT 340center. For us, audio and video has never been better! Now for the question... both these speakers have an impedance of 8 ohms, I would like to add the AXIOM QS-8's as surronds, these are rated at 6ohms. Is there a problem using speakers with different impedence ratings, why or why not? If not, what should the reciever be set to: 6 or 8, and why? Enjoying the learning experience, THANKS VERY MUCH for all the input!