Yeah you're dead on mane! I think my box was too big. DC suggests that each of my drivers require 3.5 cubed ft. So I built a box that was 8.00 cubed, subtracted the sub displacement and bracing and ended up around 7.09 in my estimation.
Now here's the thing. I didn't use a divider. Do you suggest using one? Also, My subs' displacement is .23. Now I know that I need to subtract that from the enclosure volume, however does the displacement change when you're using a double panel face? (Using 3/4 MDF)
That may be a problem as well. Even though displacement is .23, when using a double panel that number might be less. Therefore less should've been subtracted off the box volume when factoring in displacement.