Using Plywood instead of Mdf-Acoustics Forum-Acoustic Fields Forum

I have started to Master Handbook of Acoustics and i noticed Diaphragmatic Absorber section when you can see the formula. It seems density of the “panel” is important factor in design one. I started researching Surface Density of Mdf and Plywood to put into the formula and noticed even tho in your diy plan says MDF, i noticed plywood has very similar surface density so my question is this ; Can plywood be used in your build ? rnrnAnd second question if you can share your knowledge to acoustic newbie… What do they mean by Surface density of the “panel” it seems only front panel density is important not actual density of the unit ? Because i know the actual unit must be heavy and i think it is important factor too. Can you show some light in this ?