I've modified the dimensions slightly. The plans call for internal dimensions of 7.25 x 11.25 x 17.25. I decided to go closer to the golden ratio and came up with 7 x 11.25 x 18. The baffle layout is identical to the original, except the center for the tweeter cutout is 3 3/8" from the top of the baffle, as opposed to 2 5/8" in the original design.

Other things that may actually have an effect on the sound of the finished product - I plan to line the top, one side and the rear panel with 3 1/2" R-12 fiber glass and coat the exterior surfaces with this stuff:

http://www.duplicolor.com/products/truckbed.html

I have a neighbor who is a serious woodworking hobbyist, and he has agreed to help with corner rounding, driver recesses, and hole cuts. I repay him with stuff from Lee Valley - circle jigs, router bits, etc. - the arrangement is beneficial for both of us. Anyway, on to my question.

Does the 23 liter gross internal volume for the one pi design include allowance for internal bracing? I'm asking because my implementation of the design doesn't use any braces. This is my first vented box project, and I don't want to muck it up Thanks!