Right i have a 12" 1200 watt max and 400watt nom pioneer sub http://www.pioneer.eu/eur/products/TS-W307D2/print.html

i know it needs to be a 24 - 49,6 litres sub box but, does it need to be ported and what would you go for

anygood http://cgi.ebay.co.uk/12-WEDGE-ROUND-SUBWOOFER-ENCLOSURE-ALL-SUBS-BASS-BOX_W0QQitemZ320335183470QQcmdZViewItemQQptZUK_Audio_TV_Electronics_In_Car_Entertainment_GPS_Car_Speakers_PP?hash=item4a9576fe6e&_trksid=p3286.c0.m14&_trkparms=65%3A12

sod that one there you could make it ya self much cheaper than that!

It depends on what sort of bass you want dude.........it doesn't mention anything about port size.
It says it is a speaker for enclosure rather than a free-air type.
If you don't port the box you will get a tight punchy bass, wheras if you port it you will get a more rich 'boomy' sound.

i like my bass booming lol if that makes sence, ben anygood at makeing them im not lol, i need one for my sub asap

can be that hard its a friggin box! lmao yeh should be able to knock something up wont be asap thou sat at the soonest but im off nxt week so could sort something out then

Also if you do port the box the longer the port (to a point) the deeper the bass.

ummm just the price of a sheet of mdf 12 or 18 mm i spect and what ever the ports cost if ya want em, doubt ill need paying in kind from yourself at a later date would be enough

you can buy the port cones

http://www.nexxia.co.uk/Hi-Fi_Accessories/bass_port_tubes.htm

hmmm port flange

illl await to see the outcome!

If you build the box on the smallish side to save space in your van but then fill the box with insulation it 'fools' the sub into thinking the box is bigger than it actually is.
I would say use 18mm MDF rather than 12mm.....