You didn't specify whether it was a finished basement. If your room dimensions are less than ideal for the ceiling height it was recently suggested to me that leaving the beams exposed, installing a good padded insulation, and covering the whole thing with fabric would effectively eliminate the ceiling as a reflective factor in the equation. Furthermore, if the room is small you may also want to consider running non-parallel. The one great thing you have going for you in most basements is the solid floor. I'll follow this thread as I'm dealing with the same situation in our renovation of our house. I'd like to create a dedicated listening room in the basement and my ceiling height is 7 feet also. Rives should be able to help.
Marco
Marco