Right-on Rich,
Always use in this order of preference for connecting source video to TV based on your equipment capabilities:
A) Component video (Y, Pb, Pr)
B) S-Video (little round multi-pin job)
C) Composite video (the 'yellow' video cable with RCA phono plug)
D) Channel 3 or 4 (coax)
For audio to the amp, use coax (digital audio coax) or optical as a first choice, then left/right (RCA phono plugs) as second choice, and bringing up the rear is channel 3/4 as last choice.
An excellent treatise on explaining the difference is
here.
How about this for a test - get/buy/borrow/make a long left/right audio cable (with the 'standard RCA phono plugs) and connect directly from the left/right audio jacks output of the DVD player to the Q Surround amp left/right inputs. Have the TV hooked up to the DVD video output so you can see to start the movie (at this point you don't care about the video except to be sure you started the movie.)
How does it sound now?
I took some extreme closeups of the Q Amp on the Horizon we were looking at. I'll find the picture and post it to my web site if it shows switch settings and connections clearly enough so you can compare.
**Update**
Here is the best closeup that I have. Unfortunately, I didn't get a good shot of the other end.
You really should try to find another dealer that carries Winne products and listen to a couple of other sound systems. Sorry that we don't have our coach yet so I can't tell you how ours sounds (I'll let you know next week
-John