Many thanks for the advice. I don't know the damping factor of the amp, but I'm now thinking seriously of the "basement option." The speaker wires are already running along the basement wall just below the living-room floor and come up through small holes in the floor. So I'm going to see about getting very long interconnects from the preamp. It sounds like a workable solution.
I'm grateful for the help all around.
I'm grateful for the help all around.