could have platered it, could have fiber glassed one up, hell even bondo... but i work differently than most, after ALOT of studying on how to build boxxes (ive built many in the past) but i wanted to get this one up to air space dampen code., so i decided to replicate particle board, only mine is MUCH more dence, only 3/8' thick and the entire box weighs 1.1 pounds (yeah thats right) and the walls are dence enough that no matter what speaker/or amp they will not reverbarate, the enterior volume is exact minumum for a 10'' speaker which i ended up with 1.3cubic feet.