Glad we got the room size cleared up, I though you lived in a mansion. :D
The point about what the sub sees (or has to fill) still stands however since the walls are open. Essentially the sub has to fill the cubic space that is surrounded by walls.
Granted, the closer you are to...
"John, I have a Velodyne brochure which says the Vel SPL 800 is shielded."
Maybe they changed, or their website is wrong.
(look on the chart under "video sheiled" the 800 is listed as NO.)
Possibly they changed the...