To be honest. I had 2-8's in a 7th order bandpass box, the box was 1.5 for each sub. .5 for the front of the speaker, 1.0 for the back of the speaker. I had two of these moduels with a amp rack in the middle behind my seat. My system was like this. MB Quart 6/4/tweeter comp set, MB Quart 6/tweeter comp set. 2 8"s Rockford Fosgates. Each door had 2-6"s/1-4"s/tweeter. The other tweeter from the comp set went into the dash location. The 8"s behind my back. I competed in 93 in IASCA, won alot of local events, got creamed at Bigger events because my system was just a put together system, no motors, no tricks, just a plain system. I got invited to the sound off in Stone Moutain Georgia and met Richard Clark, and he open my eyes to a whole new world, about sometimes less is better. But you gotta be happy with what you got, but a good set of 10"s behind you will do the trick. Oh yeah, I used to boom and things, even with 8"s, someone dragged my car off from Toys R Us one night and I have never seen it again. Sometime Less is better.