i have a dcon 12 in a sealed box Internal box volume: 1.2 cubic ft Box Dimensions: 14-1/4"L x 14-1/4"D x 14-1/4" H Its amp is an mbquart 400w rms in a chevy 1994 blazer. it goes pretty hard but from what iv heard, it can go louder with a bigger box and a ported box. its facing the back of my car. Could i get some help on how big to build it / all of that kind of stuff? like dimensions, volume, ported size. i might take it to a local audio shop and have them build one but i don't know what sizes and stuff.