i am currently making a box for two l7 12s to go under my back seat. the majority of the box will be mdf, only half of the bottom will be fiberglass. so how many layers is enough???
it very shape Dependant, curved surfaces don't need that many layers to be solid, but if youre going to have some flat surface then going with about 10 or until you can push and it wont budge. thats the best way to tell.