Quote Originally Posted by J Henry View Post
All I can say is I heard a world of difference when I added the extra layer of 3/4 ply.
OK, you're sure he used 11 or 13 lam Baltic Birch, Apple or = no-void plywood? Even the no-void marine grade Pine I used for decades is no longer of sufficient quality IMO. Cabinet grade, while very nice looking, has a MOE approaching MDF plus voids (at least around here). Regardless, I'm in the same position along with numerous others who have posted the same results I've (not) heard, so I leave it to the 'gentle reader' to either make their own choice and/or experiment to find what performs best to them.

BTW, what are the cab's design details? If its bracing doesn't tie all six sides together to ensure it can't 'breathe', I can believe you heard a difference.

GM