Which material sounds better for speakers construction? Wood, Ply or MDF?

Here is what I would say about that.  How many CONCERT level instruments are made out of plywood or MDF?

Answer = 0

While a speaker is not an instrument in the sense that you can play it, it shares ALL of the concepts of a device, usually some type of chamber in which sound is projected for the audience to hear and enjoy.  

It would seem to me that Wood would be the obvious choice. 

@invcitus005  

You clearly do not know much about the live concert instruments.  I can not think of a string instrument that isn't made out of wood which is UNIVERSALLY individually selected.

For example, PRS guitars have 2 distinct level (this is very common among concert level instruments) General line, of which some are made in Korea and the remainder are made in the USA.  Then there is their private stock line where the woods are individually selected for their tonality SPECIFICALLY.   

That last word explains my VERY sound logic Invictus.  Woods have tonality properties that NOTHING else will reproduce. SOME have exceptional resonance qualities and these are selected by luthiers.  You know its why a Martin D45 that was made in 1941 is for sale for $350,000.00.

Its also why a 1957-1965 Les Paul sell routinely for $100,000-325,000.  New these guitars would have sold for $300-500.  I purchased my 1974 Les Paul for $350.00  Today, its worth 10 times that much.  As it ages it will continue to rise in value.

Anything that is resonating sound, AKA music, the type of wood matters.  The idea that wood vs MDF/Plywood doesnt matter is utterly absurd.  Sure you are going to pay through the nose for wood but it is a FAR superior choice.   

Just a guess, but Im betting these arent made of MDF or Plywood.

 https://www.audiogon.com/listings/lis8jgf6-cessaro-liszt-horn-speakers-full-range#&gid=1&pid...

@invictus... you clearly don't I am a professional musician  Not a single solitary vintage marshall or fender cabinet is made of plywood, MDF, or particleboard. They are almost exclusively made of Birch.  So you can flap your gums all you want but the actual fucking MUSIC is made with solid wood instruments, solid wood cabinets etc... END OF STORY