ok so I have used a few different calculators and got different lengths... the box is gunna be 4.0ft^3 for a 15" Q tuned to 32 HZ on carstereo.com calculator i got H 6"xW 10"xL 28" on winisd pro i got 6x10x 32.9 L?? what one should I got with or are there any other calculators I should look at? also what would my port area be looking at and would I be in the recommended 12-16" range? Thank for any help -Ryan