Well this question is for zane but if anyone has any input please post. zane on the link you have on the bottom of your quote .I used the calculator to figure out what size box i need. The results were way off from what my book said that came with the sub. for sealed it was pretty close but for ported it was way off here is the info
HZ 20.2
Qms 3.44Qes 0.56
Qts 0.39 Vas(liters) 117 (cubic feet) 4.3
EBP 62
REVC(2 each@) ohms 3.6SPL 92.6
xmas 32
Levc(mH) 0.9

this is the parameters that are listed in the book. I made a vented box that I plan to put it in, but if your web site is right its gonna be way to small. I made it 2 cubic feet. The book says 1.7 so I went a little bigger .For sealed the book says 1.9 cubic feet. the Web site says 4.3 cubic feet for ported and 2.0 sealed . i really want to have it ported but i don't have the trunk space for 4.3 cubic feet. I made the box already except for drilling the port open . what should i do? Would adding a port be a mistake with having it 2.0 cubic feet or is my book right and 2.0 will be fine.If it helps the sub is an Audiobahn 1500x . Please let me know what you think