This is incorrect. Solid wood resonates more than plywood or mdf.
Scott
MDF is less resonant than wood indeed, so it can be better suited to multi-ways boxed loudspeakers, where an inert or affordable material is wanted, but MDF has the known characteristic of the emduff bass, or duff.
However, the wood can warp, which does not happen with MDF.
In the 70 years my first bass guitar body was in MDF, and the tone was bad, non musical, I also already tested an e-guitar in transparent acrylic from Korea and the sound was horrible, just OK for glitter Rock Stars.
Then I came to conclusion that the resonance of well dry wood from a mature tree is very benefical to the sound of speakers, mainly no xover fullrange speakers, where the transparency is so sensitive.
I read on web about the HDF sound may be better than MDF thought, but I not sure.