Well, I'm thoroughly confused now, and no closer to figuring out what's causing the poor bass response with these speakers.
I did manage to find a spot where they looked alright in the bass department. It's a shame that it's on the floor, though.
Here it is in the same room, but off the floor about 2 feet
Finally, I tested a speaker lying around to see if the bass problem was part of the measurement, and this was the result. This is a relatively small ported...