[Trevor]

MDF is the best for creating acoustical energy in any room

What a stupid statement. VERY few musical instruments use MDF, (when was
the last time you saw a Piano made from MDF?) and even many good speaker
boxes use plywood rather than MDF.
In any case the sound from a speaker should come from the cone, not the
box, and apart from it's obvious drawbacks, concrete is far better than
MDF for speakers, so MDF can hardly be "best" for anything.
Acceptable, perhaps.

Trevor.