Thanks for the response. Upon rereading my post I realize i didn't say what I wanted it to say. I listed my current speakers simply to give some background. I want to replace my Vega center right away. Secondarily I will be swapping out the yamahas. All my current speakers are 8 ohm. The Axiom 150 center channel is what I'd like to upgrade to. The question is: Can the onkyo drive a 4ohm speaker at the same time it is driving my remaining 8 ohm speakers? I cannot afford to get all the speakers at once, and if I can't drive a single 4 ohm + 4 other 8ohm speakers, I'll get the Axiom 100 center instead.