Yes I found the 'sub' switch right after I picked it up but it did not do anything with the TV or SAT so I figured since I had fireplace it did not have a sub.
I put a DVD in for the first time a few days ago just testing. Found that there is a sub and it's great for finding the rattles in the fireplace. lol
Seems the sound bar is fed by the RCA jacks. But all those speaker wires go into the hole in the side of the cabinet. Where to? hmm, I'll ask the guys at the factory today and let you know what they say.
The drivers seat is a different story. Those 2 little tinny speakers. DW can stand it for about 5 minutes then makes me turn it off because it gives here a headache. But There is lots of room under the dash for adding amps and a sub. I can fix it.