Hey everyone i'm new on the forum and Polk audio sub's. I've allways had pioneer's but it's time for a change now.I have a 2003 Ford Escape with a MTX 250D mono amp pushing 3 12in pioneer DVC'S in parelle in a sealed box. All my friends could not belive how hard this sys. was pounding.A week later I blew a sub so now I would like to change to a Polk but know nothing about them could you steer me in the right sub area on model and if I should use a single or duel vooise coil for my MTX 250D mono amp? And also I am change the OEM 5x7'S door speakers out to the EX572 5x7's with no amp just a Sony m630 head unit pushing a max of 52 watts x 4 to the speakers. Would these speakers be good and sound nice just from the head unit? The box fits 3 subs at 1.2 of air space per sub.