My guess is that it is using the power from 2 speakers of the 7.1 setup to drive your Speaker Set B and hence it reduces it by 2 to 5.1

Option 1: Get real- there are no 7.1 DVDs out there yet ;) Stick with 5.1 and keep in mind 7.1 is only marketing

Option 2: Buy a cheap reliable stereo reciever (I like Yamahas- they are quite dependable and can be had from craigslist for about $50) and connect it to the Tape Out outputs from your main reciever. You can connect your speaker selector to the 2nd reciever

Thanks. The reason I'm trying for 7.1 and not 5.1 is that I plan to add the two ceiling speakers in the living room near the receiver to the surround sound instead of via the speaker selector unit as I'm maxed out with selector spaces. That will allow for three speakers up front, two floor speakers and the ceiling ones. Sound logical?

We've been 5.1 for a long time. I talked with a stereo salesman and he said that I should not upgrade to 7.1 unless my room was at least 30 feet long. I'd go with the music in each room and not worry about 7.1 sound unless you have an extremely large media room.

You do NOT need another receiver.

What you need is another amplifier.

1. AudioSource Amp300 ($599.00 MSRP) would work well.

2. Onkyo M282 Power Amp ($320.00 MSRP) will do as well.

Using the Onkyo 603 room 2 function, you would connect a pair of RCA connectors from the 603 (I believe the tape out is assignable to room 2 out) to the outside amp, speaker wire from outside amp to the slector box.

Thank me later......