Yes, John, that's what was happening.

Chris, instead of a CD player, I used my portable MP3 player (or in my case, FLAC).

I know the back drivers work because they were operating when I would put it into DPLIIx Music mode. However, I put my system back to how it was before I tested that the DSP was outputting the rear driver information. I had double-checked that they were going into the correct multi-channel inputs on the back of the receiver, but even so, there's that little bit of doubt that makes me think I should have triple-checked. So it could be either of those things (or a glitch in the receiver's functionality), but I think I really will wait for the amp this time. I'll tell you what, though; I really can't wait to have an equipment closet with easy access to the back of all of my gear via the room on the other side. That will make all of this reconfiguring so much less of a headache.

By the way, my dad had a big sheet of wood that we cut to block the entry behind the left LFR, so that should give me reflections on that side, at least. It's not pretty, and I still don't have the space to play much with placement, but at least it will give me an idea on the LFR sound.