Looking to purchase plans for an id12 box for my van. 2 cubic feet tuned to 30hz. Max dimensions are 14 high 12.5 deep I could do 13 here if I cut an inch off the height and 40 long. Can cut 45s as well. I would like the sub to fire up if possible the mounting diameter is 11" but don't know if that is safe on 12.5 or 13" post here or pm me with price. I really need to get this done asap.