I wasn't aiming that at you HHNET, after you called the switcher a router, I went and did a Google search and noticed that some do call a matrix/switcher a router now and being in this type of business, had never heard it referred to as a router. The newest HDMI standard is now a two communication, so if the devices being used support this standard, then your method will work fine. I replaced my ceiling speakers in my older Jayco that I no longer have with some residential 6" speakers ( had to cut the hole larger ) and they sounded 100% better. One of the originals was bad though. That TT had a Jenson DVD deck in it. My current Pinnacle has a Jensen unit as well, but I never use it. I installed an LG Blu-Ray HTIB ( Home Theater in a Box ) system, used the 2 front's that came with it, put the subwoofer in the back wall of the tv lift and disconnected the "B" speakers from the Jensen for my rear surround, and all works great. The sound is 100% better than the "A", and "B" was thru the Jensen. I don't even use the outside speakers because I have a bluetooth Boombox that also plugs into my Directv receiver that is mounted in my underbelly compartment.
2012 36REQS Pinnacle w/ Reese GooseBox
Stays at Lakehills, TX on Medina Lake most of the year!!
Chevy Silverado 3500 Duramax Dually