I need a good box design for my 4 18s build in my Tahoe, the truck is a square body 4 door 1996. Max box dimensions are 22 inches in height, 47.5 inches in width, and 39 inches in depth. For the box I am looking to do a kerfed port design, or just a large open square port. Tuning frequency will be 32 hertz for 4 Fi audio BL 18s on 2 Twisted sounds 3.5ks. Looking to get about as close to 6 cubes per woofer as possible. Please contact me for more information on the build and truck. Thank you.