Re: 1 Obsidian Audio 12v2 Enclosure help.
That is about the same dimension I have to work with, and it is hard to fit a 12" sub in that space and keep your tuning around 30hz.
You can either raise your tuning, or carefully design a box with two 3" areo ports. I think it would come out to around 17" a piece. You would have to fire them out the sides of the box to keep it within the space constraints.
You might be able to get by with a slot port, but it will be a tight squeeze, even with 30" wide to work with... It will fold at least 1 time, 90 degrees... It should be around 23" - 27" of port, depending on displacement.... 2 x 12" slot.
'65 VW Bus
MA Hippo 122, (2) Aura Sound 8's, (2) SoundStream 6.5 coax, (2) Alpine Type-S 6x9's [rear fill], MBQ DSC1500.1D, RF 501X
'02 BMW 330xi (AWD coupe), every option
Harman/Kardon 12-speaker System Option + Dayton HO D4 10" and PPI Ion 650.1 in sealed box
And many more car audio goodies in storage