I moved the Boom from the study (a 2.5 m cube) to the living room (5m x 4m space) to see what effect the room size had and here are the spectra:
These have been calculated from a day of record, using 10 min windows and frequency averaging with side lobes of 5 points.
The study has a concrete floor, whereas the living room is fibreboard on 1 m high wooden piles.
Evidently there is oscillation in the study at 5.73 Hz and higher harmonics that is not replicated in the living room.
In the study, the Boom was at the wall on one side. If I put it in the very middle of the room, will it be at a node, where the amplitude is zero? I’ll try it.