Thanks a ton for this!
I am looking at maybe buying an Empty Sunn 6x12 Cabinet and if I am successful I would likely load it up with some 12" speakers (2 sets of 3 speakers in parallel, with those 2 sets in series) to drive the Coliseum Bass at a full 2 ohm load.
I just need to find some good 4 ohm 12" bass speakers... hmm.