[Click here to view inside the bottom of the box]
The reason that the bottom is removable is to accommodate the replacement of the rear mounted woofers - as they would not fit through the holes in the front of the box. There is no other way to get inside the box, because the rear woofers are screwed in from the back of the baffle, the mid bass is in its own enclosure and the midrange and tweeter are in small isolated chambers as well.
Once I am completely satisfied I do not need to get inside the box for a while, I will seal the gaps around the bottom panel with caulk. If needed, I could still get into it with a razor knife and a screw driver.
The fiber fill has not yet been added to this box, nor has the 1/2" of particle board been laminated onto the outside of the box.
You can see the bottom of the two rear mounted woofers, a couple of the 3/4" thick laminated (isobaric chamber) wood layers, the crossover, the port tube (4" id white) and the mid bass tube (6" id green). The plastic tubing used in this project is very heavy grade stuff - 3/8" to 1/2" wall thickness.