Check out Digital Designs 9500 series, my soundoff team is running 2 vehicles with 9515s. Meg's is running on a concept CC-D2400 1/2 ohm daily driver, 148.3 db, 1 15" sub, 1 amp. The other one is hitting 150.3 with one sub running at 2 ohms on a pair of strapped concept CC-D2400A s, 1 15, 2 amps. Both on an audiocontrol 3065. I tune boxes to the car, not the sub. run the sub in a box, outside of the car with the mic a foot from the box. place the sub in the car, then run it with the mic on the dash, see what freq you gain the most at, tune the box to it. I watched an owner of 2 15" L7s jump out of one of our cars because he couldn't handle the sound pressure level. I would find the nearest DD dealer in your area. If you call DD they will direct you(405)239-2800 is there number american made in Oklahoma City.