I *think* this subject came up a year or two ago and someone from Axiom responded. The gist of it was that a ported speaker could play lower but a sealed speaker could handle higher power and higher audio output in the freq ranges which did matter for a center channel. Again, this is only vague recollection so it's possible the post did not come from someone at Axiom.

Also, it just occurred to me that the reason Axiom may not be using 6.5" woofs in the center channels is that the larger cone makes for poorer off-axis response. According to Alan (again, IIRC, YMMV etc.) the poorer HF off axis response of the 6.5" woof is why the M3/M40/M50 have a slightly more laid-back sound than the M2/M22/M60/M80.


M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8