These were homemade subs, built, owned, and operated by someone else. I know all about boundary loading, and being concrete, there was nothing transparant about the walls. I prefer not to boundary load and instead use more subs. Its not like the mouth of hte box is flush with the wall. Sure, we're talking about long wavelenghts, but its approaching 80 hz that im not cool with the wall technique so often.
So, were these guys likely just facing their subs the other direction for more protection against destructive guests? I cant imagine their polar plots were anything but omnidirectional, but have seen cones punctured with pens.