Hi Earl!
You wrote,
"and thus has its output about five feet in the air - intentional to get it away from the floor."
Sounds like a good idea. Is the sub placed five feet from the walls as well to get less room gain? Might be good to do if you have space or?Isn't fs of B&C speakers too high to be used as subwoofers? How come you're not using for example Peerless XLS12, Eminence LAB12 or NHT1259?
/Mattias