How Do You Calculate The Airspace Of A Non-square Wall

[Sniper]

so i've been considering walling my first car, but im curious about something, how do I figure the box size for tuning?

it'd be a non-square box too, much like how Chicken's Hoopty is, well, it wouldnt be with 4 18s per side though, im probably gonna just throw 20 10s in a car or something, i'll figure out some way to do it. (What i've always said is All or Nothing & Start off with a bang)

so erm, yea, im curious how i'd measure the size when the corners would be sloped on the inside, and how to figure the displacement after all the corners have been 45'd (well, internal bracing 45s, and wooden dowels)

[Boon]

You can take 2 approaches...

The first is that because the wall is (relatively) huge a cubic foot either side isn't going to make much difference in tuning so just work it out near-enough and go with that

OR

Build the wall and get in there with a tape measure and work it all out If you learn to use something like Sketchup it can make it pretty easy too, build the wall, measure it, model it in Sketchup then use that to find out your exact volume.