Is 3.75 CUFT too much for a single 12" X/Zv4? Technically it would be 3.83 CUFT. The box would have a slot port that is 4" wide, 25" long, accounting for 0.83 CUFT of space, reducing box volume to an even 3.0 CUFT. Port area is 60 SQIN, resulting in 15 SQIN per CUFT of box volume. It would be tuned to 35 hz. Too big? Am I good on the port?