Hello Ajax,
My living room, where I listen to music is about 12 by 16 feet, the dining room is adjoining and mesures 11 by 10 feet. The total size of the main floor, all open space, is about 4500 cubic feet. I do not have a RCA Sub out on my receiver. So if I understand want your saying, I have to connect the sub with speaker wire to the receiver and I also have to connect the sub to both mains?
Thanks a lot,

Colleen