so i got my new btl 18 and i love it. I was not expecting it to have so much output but still keep its sound quality. Love it guys so keep doing what you do. So here is the box i built for it this last weekend. 7 cubes with disp tuned right round 34 htz. Most corners 45 with fiberglass with double baffle. The sub is ran off a Hifonics gx3000, and the set up is in a 1998 chevy astro... more 18s to come soon