Thanks for the reply. Is the DSP-AX757 I have, and after reading through the manual again (in particular those pages you pointed out), I'm still not clear.
It mentions that zone 2 is only available in the RX757 (using the presense speakers) version, but I have my front B speakers set up as zone 2, which is what confused me. I'll try those remote comands (p 77) again and see if I have any luck.
I think you're out of luck on Zone 2.
I believe it's only available on the RX-V757 and yes, you can select a different source. A pre-requisite is use of the analog connects and connection to the presence/speakers, if you want to use the internal amp.
Yes, it looks that way. I am able to set the B speakers as zone 2, so that if they are on and A are off, then the surround and sub are also off. Doesn't look to be any way to use a different source for A and B though.
Multi room is only usually available from the surround back speaker outputs, sacrificing 7.1 for 5.1. The A and B speaker posts, are the same amplifier channels so it would be impossible to send different sources down them.