Charlie,

One way to find out where the .1 goes is to use Avia or VE's test tones (or even any disc that has that THX 'optimization' test tone, I own 4 or 5, I think) with your speaker set-up. There is a discrete .1 signal with no other signal, so if you hear it, then it is re-routed. If you hear the main channels hiss, then a few seconds of silence, I'd suspect the .1 is indeed on the floor under your couch. . .

S.