The appearance of the enclosure was the most important element of the project, so this is what I put the most thought into.more on that in the assembly. I chose 3/4" MDF for the structure and a combination of 1/4" and 1/2" red oak, and white poplar 2" and 3" wide boards for the "skin". I used the Parts Express woofer selection guide to determine that the volume for the Goldwood needed to be 0.8 cu. ft. for a sealed box. The width of each cabinet was governed by both the width of the woofer and the board placement. I wanted the oak to stand out a little more on the face, so I used the 3" wide oak boards which worked out perfectly with the width of the woofer. The depth was established by the width of the boards for the sides as well as the mounting depth of the woofer. Finally, the height was determined by merely wanting a decent spacing between the drivers for the wood to stand out. The inside volume ultimately ended up being a little larger than recommended for the woofer at about 1.3 cu. ft., but I felt the overall appearance was more important. Titanic kit.