A rather productive if confusing morning. I took about 40 waterfall measurements with REW, most with all but the semi-permanent acoustic treatments removed.
Here is the baseline measurement for the listening position.
Listening position, no treatments
Listening position, MT and soffit traps installed--they don't seem to do much...
Listening position with 2 monster traps and 4" DIY 703 + mass-loaded vinyl trap stacked vertically behind listening position. Now we're getting somewhere, but it took 18" of high density fiberglass plus mass loaded vinyl, and the effect is only local.