My room is 20.5' long x 12.5' wide by 7' high (a basement). It's got three LF peaks, the most troublesome musically being right at 100 Hz. This is +3 dB in one channel and +5 dB in the other. Maybe a little more, as those are my parametric EQ settings, and usually I slightly under-correct.
I don't want more treble absorption, or even around 200 Hz, so the Scopus 100 with an Alpha plate looks like a good possibility. How many Scopus 100 would be needed to make an audible difference in the room, do you think?