JimJ 5,000+ posts
Tangled Up in Blue
A local lumberyard should stock it...most home improvement places don't stock anything over 3/4" in MDF or BB...
JUST THROWING IT OUT THERE.....BUT....couldnt you just get 1" MDF, get a bunch of sheet metal, throw dynamat on the sheet metal and then sandwhich that in between the 2 pieces of 1" MDF, so it wont resonate.?