MDF versus Baltic Birch?

MDF is poor choice for loudspeaker cabs. Sure easy to work with and afordable but veneers don't hold as well to MDF as ply its easy to veneer MDF but venners will lift off MDF. MDF will absorb water like a sponge. MDF strores energy which colors sound. MDF is easy to crush or dent unlike ply. Dont see to many ply cabinets with crushed corners. MDF also since absorbs water will form scary molds within days. Try it for yourself dampen MDF slightly, lay it so no light reaches damp spot in days dangerous molds form. If you intend on using loudspeaker in humid or slightly damp places like basements I would pass on MDF. You can do the same with ply and little to no mold forms and the stuff that does form on ply can easily be removed unlike MDF where mold will penetrate deep into material. When I use MDF I make sure MDF is fully sealed inside and out. I have open MDF cabs and found mold growing on inside of cabs. So my finding are PLY like Baltic sounds better, holds veneer better, lasts longer. Is far stronger and safer than cheap old MDF. And I too have tried layers of MDF PLY other materials and doubled Baltic has always come out sounding superior.

Wow, great info guys. The MDF sheet that I have is the kind that can stay submerged in water w/o swelling (it's for use in the humid islands here and the supplier has had a sample piece in a 5 gal. pail of water for 2 yrs for display purposes). But even so, it sounds like biting the bullet and buying more Baltic for re-enforcement is the best way to go overall. Thanks to all

What type of glue are you going to use?

I'm presently at sea working on a ship, but as I recall it's called "Tight Bond". It's light brown in color and water based, very similar to Elmer's cabinet making glue but slightly higher on the food chain - unless someone can talk me into something different.......

Titebond II or III is what I use.