NEED help with square port

[jpar721]

I need some help with the size of a square port. I'm making a box for 2 type r 12", the box volume is 4.2sqf, due to limited space in trunk I'm only going to have 3" max for the port width, the height of the inside of box is 13.25", I want to tune the box to 31-33hz what will the length of the port need to be? any help will be appreciated,. Thanks.

[BIG MIKE]

port length: 20"

[hardhittingpunch]

lol

[jpar721]

Thanks..

[galacticmonkey]

and if you ever need it for future reference, here it is


http://www.carstereo.com/help/Articles.cfm?id=31