I have a pair of ported 15's in it atm, only JL 15w3v2's running off a Sundown 1000d, but i want to do a sealed box this time. Mainly something different. and it's not everyday ya see 2 18's in a S-10, lol. My thinking is, i want to be louder than my current system, but still sound good, so i am thinking 2 x-con 18's off of a Sundown 3000 or 3500 should def. do the trick.