My designs basically got shot down when i found out more stuff because I'm new to building this stuff and i want to do it right my first time...for the box DC says 3.5 cubic ft per sub and i want 4 so 14 cubic ft plus sub displacement for all of them which is .72 cubic ft and then everything else ...so i planned on a box 1.8ft x 3 ft x 3ft but i can change this (i need to fit this in and area thats 2ft x 4ft x 5 ft) tell me if you need any more info