Forget everything I said.

This receiver is meant to work with five speakers for surround in one room.

Period.

Anything else you do will be hokey, cumbersome to operate, and might blow the amp. I don't know Sony receiver models (except to avoid anything stressful on any unit that's not an ES) and I thought this was a real receiver meant to work with whatever speakers you choose, with real outputs and speaker A/B switching. Doing what you want with this system is like milking a bull: if you do figure out how to do something that vaguely resembles what you want to do, what comes out will NOT be what you wanted!