A lot of work!!
You can use as much wood as you can and do the rest with fiberglass and Dynamat the inside of the box.
Here some of the boxes that I built, and the front panels for my sub box.....
[IMG]
[/IMG]
[IMG]
[/IMG]
[IMG]
[/IMG]
[IMG]
[/IMG]
[IMG]
[/IMG]
[IMG]
[/IMG]
[IMG]
[/IMG]
[IMG]
[/IMG]
[IMG]
[/IMG]