eddie7978

has anyone tried to close the big holes in the doors for more midbass?
thinking about maby then metal and some screws?

AdrianClayton

I used sound deadening material on its own and I feel it has made a big difference. the hardest part is not interfering with the door lock and handle rods. I recommend if you use metal that you sandwich sound deadeneing underneath to prevent rattling.

petr0lb0mb

Yep, years ago, I did it in my Integra with Dynomat. Was super easy and made a very noticeable difference reducing road noise, but a bit costly. I had baffles on the speakers too, though so midbass was unchanged for me.
Baffles are cheap and might help you accomplish your goal.