Actually, and this is where it becomes fun,I was thinking of the M2 with one 5.25 mid woof.
the M22 with two 5.25s
and the non-existant M222 with three 5.25s
But you are right-the M222 would(if it existed)be a bookshelf, so...
Would a floorstander be an M...uh...
Oops..ok, it's not fun anymore!!!
Well, it was fun while it lasted!
Rich.