First qustion i no its pretty noob but to attach mdf together i predrill then add wood glue and screw in the predrilled holes correct.

also i am trying to make my corners rounded where two piece of mdf are meeting

also i got a ring so the sub would mount to and then i am going to attach it to the box so it will be flushed mounted do i do them as predrilling etc or do i need bracing

heres a link to my build log so you can kinda see what i am working with

My Nissan frontier build

sorry about grammar and spelling been a long few days of fiberglassing

Edited April 11, 201015 yr by klee7013

You should pre drill both pieces together, then glue, then install screws.

As far as the corner rounding , either use a router or a sander.