MDF versus Baltic Birch?

Baltic birch is a better choice for rigidty than mdf.

How about both MDF and Baltic Birch My speakers North Creek Music Systems the Manifest has a cabinet built with Baltic Birch on the inside and MDF glued on the outside. The MDF is easy to veneer and you get the stiffness of the Birch inside. The two layers also give you a stiff cabinet always a good idea I also used Birch for ladder braces inside the cabinet for stiffness. George from North Creek uses a hard glue between the MDF and the Birch and a soft glue between two layers of MDF plus a layer of Birch for the front baffle 2 1/4 thick front with two layers of MDF , Baltic Birch + MDF 1 1/2 thick back and sides and 3/4 inch Baltic Birch for ladder braces. The hard glue is tight bond and his own soft glue hope this helps Marc

It might work. I haven't try it tho. I had a similar idea ones but instead of old plain MDF, I was thinking of using the product which name escapes me right now (I can find out its name if you want). It is a laminated MDF and Ply in 5 layers (top, bottom,mid MDF and Ply between). Cabinetmakers use it on special occasions when rigidity is of up most importance. It's the perfect material for your project, easy to work with and finish. Price might be an issue but I do not believe that it is more expensive then Baltic Birch (void free) Ply. If I had to guess, it might cost somewhere around $80 per 8'X4' sheet these days. (year ago it cost $60).

I hope it helps

Mariusz

As to glue "Q". I use exterior (water proof) grade woodworker's glue in most applications.

Mariusz

Most speaker cabinet makers use special dampening glue or material. Depending on the designer they may use braces or special glue to provide better rigidty for MDF or layered Birch.