ok i drive a regular cab truck with 6x13x36 clearance behind the seats and i have subs that require 4 cu ft of space and have a 1.5 inch excursion. my solution was something between an aperiodic box and infinite baffle. i have a box 3x13x36 with the subs facing backwards directly into vents (not ports) that vent outside the cab. it all sounds good but im wondering if there is a way to tune this by changing the size or shape of the vents. i also wonder if its going to hurt my subs since this is basically free air and their meant for sealed which isn't gonna happen in my truck. i figure it wont hurt them since they have a really sturdy suspension.