why not? ha!
mostly because it's a SQ set-up and didn't want the subs to overpower everything by having them pound directly into my back or right behind my ears...
the meter numbers?

i haven't metered it. i won't meter it. i have no interest in the SPL numbers - more interested in the frequency peaks/valleys and the imaging of the front stage for overall sound quality. (i'm more old school that way...) don't get me wrong... i'm sure it would 'meter' well. i mean, they're two resonant engineering 12" MX's with a solid supply of power!
(sipping beer...)
at one point i was even thinking about putting the subs in an acoustic suspension enclosure to maximize SQ - but didn't have the mono power from the M2 to feed em' what they'd need in that type of environment (less efficient enclosure). In the end, I went with the bass reflex enclosure for more efficiency, but again, didn't want em' pounding directly into my back/ears so up they went!
besides, i had *really* good results from my two mtx 10's in two decware deathbox's that had ports firing up (granted different enclosure, etc., etc...)...
(sipping more beer...)
the spl craze is sad to me. Just my view. There's more to music than trying to figure out how much money you can spend to loose your hearing in the shortest amount of time...
i dunno. i need another beer... ha!
(it's been a rough day).
-biju.