I have a 2016 Ram 2500 cummins that i am attempting to put a system in. The local stereo shop sold me a pair of JL 10W1-v34's and a box that fit under my rear seat. they sold me a JD600/1mono amp which i have since replaced with a XD 1000/5vd2 amp. I have a kenwood DDX 8906s deck and kenwood component speakers in the doors. when i first heard the subs i was incredibly disappointed. It sucked. after looking at the box they sold me it looked to small for the .55 cu ft that each sub requires in a sealed box. I wasn't sure because i don't know how to calculate air space on such a irregular shape. I decided to build my own out of fiberglass after watching several videos and it turned out great. i molded it to the same shape that fits perfectly under my rear seat and added a spacer for the rear seat and could tell i had way more air space, it's 100 times better than it was but it just still does not sound quite right with some distortion and sounds kind of loose to me. i fear the box is now to big and overall I am still not impressed and was hoping for louder better sounding bass. i've heard good things about the subs and i just feel like its the box but dont know where to go from here. any help is appreciated and yes I am definitely a novice when it comes to car audio.