box help please

[steve c]

gentlemen,
currently i have two alpine type r12's in my 08 scion xb. They are powered by 2 alpine v-12 600w amps. The box that I am using is a store bought sealed piece of **** that really sounds like crap.
I'd like to venture into the spl world with my current set up. Obviously i need to use a ported box but I'm unsure of the cubic feet and port area required to achieve some "nice bass"
any suggestions would be greatly appreciated
the workspace dimensions:
20" depth
40" wide
16" height

Thanks
-steve

oh a picture of the current set up. the only difference is the amps are mounted in the c pillars
http://img73.imageshack.us/img73/6537/l7937f43559af5b56627178xd1.jpg (http://imageshack.us)

[BASSMEKANIK]

4.5 cubes 72 ci of port.

[alvitae]

Let me find this nice calculator I like that gives freq graphs and cut out sheets and is really easy to use. brb

http://www.subwoofertools.com/calculator_display.ashx

There it is.

[steve c]

jesus i forgot how quick and dirty this site is... thanks guys...

just to make sure I'm not retarded 2.25 per chamber and a combine port area of 72" (36" per side)

Oh does anyone have a problem with this system firing up?
I don't think I have the room to face it towards the trunk lid

[BASSMEKANIK]

id do a comon chamber myself...

if you have room to fire them up then you have room to fire them back.

[BASSMEKANIK]

id do a common chamber myself...

if you have room to fire them up then you have room to fire them back.

[BASSMEKANIK]

id do a common chamber myself...

if you have room to fire them up then you have room to fire them back.

[alvitae]

Don't ya just hate the **** lag on this site :)

[steve c]

hmm so common 4.5

where should the port be?