I can e-mail you enclosure plans.
I like MDF myself, but you can use Baltic Birch on this cabinet.
The radius on the back side can be 3/8" to 1/2 on 3/4" material.
The best mods are upgrading the caps to Sonicaps and lining the cabinet with No Rez.
I also have two choices that would be cheaper for me and match my furniture.
I would like the front baffle to be the same thickness the full 48" length.
( That is what most of the pictures of the X-Statik looks like)
Can I do either of the following and if so what thickness from 1.5" to 2.5" would be ideal? Which would be the better choice if it would work?
This first on is 1" wide quarter sawn Red Oak 1.5" to 2.5" thick.

Or a solid 8.5" x 48" quarter sawn Red Oak board 1.5" to 2.5" thick?
It would be easier to make and finish the front baffle for both the X-Statik and X-Voce and fasten the woofer enclosures to them.
It looks like four sheets of No-Rez would just cover the three enclosures. Am I correct?
I am covering the last details to get a good idea of the total cost.
Thanks for all your help on this.