I've got a fiberglass bottom box for my spare tire well. It's difficult to measure the volume but I pulled the driver out and did an accurate conservative measurement on it today.
It's 1.77cu ft without driver.
I just ordered an elemental designs e5.12 12" sub.
reccomended sealed enclosure size 1.2cu ft ( I verified this by running the numbers 1.12+ .08 for the driver)
recc vented ideal 1.5 @30hz
recc vented db loud 2.0 @35hz
driver displacement .08cu ft
I'm torn I don't know what to do. I like low bass and It's not going to hit very low without being ported. I'm kinda confused about calculating the stuff for ported boxes.
If I do a port it will have to be 3" and will need to have at least one 45degree elbow maybe 2. My box isn't very deep (only 9.25" at the deepest place), so I definitely need a bend in the port.
here's some pics of the box to give an idea of the shape
and here it is with the cover on. there is about 3 inches between the box and cover.