Custom Subwoofer Box Help JBL P1022

[RetroLite]

Hey i was wondering if someone could shoot me a few sizes for a box to spec for the JBL P1022 Subwoofer, Previously ive had boxes made but this time i would like to make it myself.

The Specs for the subwoofer are here

http://www.jbl.com/resources/Brands/jbl/Products/ProductRelatedDocuments/en-US/BoxesandParameters/P1022rev3_27_06.pdf

Thank you,
Dragos

[TheMaterial]

http://www.the12volt.com/caraudio/boxcalcs.asp

Just input the proper numbers and have fun.

[RetroLite]

Hey thanks Ive tried using AJ Sealed Designer 2.0 and having entered in the subwoofer specs from the manufacture it tells me that it needs a 32.2667 L box but why does JBL specs say it actually just needs a 21.24 L box (both being sealed boxes)? Which one is right?