I tried using the box calculator but really didn't understand so hear we go again I have a sub box it's for 2 12's it's 3.5cuft and the port is ( 14" length, 2" width,and 16.5 depth) it's a slot-port the wood is 1 inch thick. What is the tuning of this SLOT-PORT ? and can anyone give me exact measurements for a Slot-port for this box that is tuned to 45hz ? (3.5cuft box)