My bad, the height is about 20”
Here are my measurements : height is right at 21”, length is 4ft and a half inch, my depth at the bottom of my seats seems to be a good 11 and a half inches but narrows up 7 1/2 about halfway up the seats and near the top of the seats it’s gets to about 5 and a quarter inch deep.You should be able to fit some non-shallow mount subs in that if you can use that full depth.
Okay thank you so much!I would consider a full size 12 or a pair of 10's maybe. You'd have to see how you could do the port, that can be problematic because a lot of times you have to shrink the box to not suffocate the port.