I'm working on building a custom speaker box for the rear of the van. It will house 4 6x9's. I think I have everything to build it. My uncle is a carpenter and he is out of town, so I will wait until he is back to begin assembly.
Here are some pictures of the materials:
3/4" mdf, 3 bookshelvs, 2 8'1", 1 6'
5lb acusta-stuff polyfill.
Liquid Nails sealer, deck screws, wood glue, l brackets, more screws.
I still need some box covering.
Here is the speaker template from Alpine:
MDF:
Polyfill: