what does it mean with a front mount displacement and a rear mount displacement. there are two different values for these. the rear mount's value is larger. i know it has to do with how you mount your sub but i don't know which one it is. i'm just going to mount mine regularly, not reverse mount. i'm calculating my box right now and need help.
front mount displaecment is how much volume the sub takes up inside the box if you mount the sub from the outside of the box, with the outer ring of the sub outside, screwed to the box. like dropping the sub into the box to mount it.
rear displacement is if the sub is mounted to the box from inside so the speaker sits fully enclosed in the box.