Fred, I was using about 30" sitting and 60" standing. Certainly not enough below or above mode minimum to explain anything like the reported bass effect, but I mentioned it.
I'm a bit taller than average but the numbers I use are 72" standing and about 54" sitting. With an 8 foot ceiling and bass source 6" off the ground (Riker, how far off the ground is the port ?) then that would put my ears right at the null when sitting (I think).
Presumably turning up the volume would make the bass come out a bit further from the speakers before falling to the ground, but I'm sure someone has already mentioned that
