Ok. Outter Dims are 20 tall, 44 1/4 wide, 32 deep. I only need 8 cubes so if necessary take from the depth. I want to run 4 audioque sdc2.5 12's. I want to do 3 aero ports and i want to tune to 38 and also i am going to buy 3 more aeroes and make them a different length so i can swap them out to tune to 35
Im not absolutely sure this will work since i dont know the outer diameter of the sub. but it is a guess that the outer diameter of the subs are 12.45" and the mounting hole needed is 11.1875". if the subs outer diameter is greater than 12.45 the box will have to be made wider. by .5" to accommodate it.
Box is 44" wide, 20" tall, 21.5" deep, 3 ports 4x5.75" for a tuning of 38.3, box is 7.98ft^3 (including port and .28ft^3 for the subs.), Subs and ports are on the top.
Yea most 12" subs have a cutout of 11.1875 but their outside diameter can range from 12.25 up to 13.25 so the cutout doesnt help much when placing subs.
The ports have a vent mach of, ~.05 at both 35 and 38 tunes. if you went with 4 ports, it would drop it to ~.03 not much of a difference, when i build boxes i like to keep it .05 or lower. only reason why i didnt suggest adding a 4th one.
Basicly It has to do with the resistance of the air flow going through the port(s). When your port is too small the Vent Mach goes up causing you to hear the noise of the air going in and out of the port. Normally anything under .06 you can't hear because by the time you get the sub pumping hard enough the sound of the music is drowning out the port noise unless you got your ear right up to it. Anything over .10 your just asking for trouble, although some people say .15 and lower is fine. I beg to differ, if your vent mach is at .15 your just going to kill yourself cause you can't stand the noise. I try to keep my boxes at .05 and lower