well i had 2 mmat p3.0 12's in a 4.1cf total tuned to 38hz if i remember correctly been a long time since i built the box. any way it was built for the 2 mmats. i was running a 1000.1 mmats. now i have the same box with no subs plan to run the new subs(12's) on a kicker 750.1 so must be available in a fashion to allow 2 ohm operation. wanting to use the same box. the rest of my system is jl 5464e (6454e?) running 3 pairs of ID ctx 6.5 components got those temp. in the car so i have some decent tunes until i find me some woofers and do a permanent install. i can never decide i have been looking for a few months now. i am intereted in trying ultra. looking for that elusive sql sub. and i tend to stay away from jl subs. any suggestions? i can run 375x1 on that kicker too. also i am rather abusive to my equipment so durability is a must.