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

@helomech Thanks for the informative reply.  Clearly you have found the items that work best for you in your room and for your musical taste.  As a former dealer, THAT WAS JOB 1 for us!  I suggest the boxless speakers only because we had much success with them and when A-B comparisons were made in our shop, they came out best.  Remember, this was in the '70s-'80's, so life and speaker technology  has improved dramatically since then.  I have seen $200,000 speakers for sale for homes...no comment.  Interestingly, I have noticed that many manufacturers are either raising their speakers on stands or designing them to be 6' tall.  I wonder where they got that idea???

Finally, a listener is NEVER WRONG!!!  You like a, I like b.  If we all liked a, life would be boring and only one company would make speakers, not over 300 at any given time.  I love the hobby for many reasons...some because I am retired from the business!...and respect everyone who is involved from any perspective.  It is a great hobby with music at its core.

All I can suggest is that you find a super-high-end dealer in your area who has the latest 30.7's running in a proper set-up and give them a listen.  Of course they are ridiculously (to me) expensive, but seeking the best and then buying what you can afford that gets you as close as possible is what the hobby is all about, IMO.  I hear you loud and clear that you found better than the 1.7 units.  Possibly the company has heard you as well and has figured out how to fix that--at an outrageous price.  Then again, that is the way of the world.  Race cars pretending to be daily drivers cost a bundle but don't do any better getting you from a to b than cheap cars.  But a prancing horse on your car costs a ton more than a bow tie!  Enjoy the music...

Cheers!

Laminated bamboo is the best sounding loudspeaker cabinet material I've heard.
My Bache Audio speakers have 3/4" bamboo cabinets.  Devore Fidelity also uses bamboo. 

It looks like my pick is also aluminium. Heard many designs sounding superior. Genesis 7 is one of them

There are a ton of excellent speakers made of many types of materials.  In the end, as long as a cabinet is well designed with the cabinet included in the design,  the drivers and crossovers are still more important to the overall design than the cabinet material itself. 
Again, well thought out, well designed speakers that include the cabinet material in the design. 

As to the question of the OP:  the heck if I know.

But just from user experience:  I've had tons of speakers of all sorts of designs, from the "we let the specially selected wood resonate with the music" (Shun Mook speakers), to Harbeth (Super HL5Plus),  to many MDF boxes (Hales, Audio Physic, Meadowlark, others), to Quad 63,  MBL radialstrahler with their carbon fibre petals, to Waveform (currently Mach MCs -which are almost a solid giant egg of layered MDF), to my current Thiel 3.7 and 2.7 speakers which use curved plywood cabinets.

They all sounded great!   I'm a "tone first" guy, and the MBLs have gorgeous realistic tone and presence, so do the Waveform speakers, so do my Thiels.  And I've been listening to Devore speakers quite a bit recently the O series made of plywood.

I'd say that a common thread among the "let the box resonate" speakers is a rich, full warm tone.   Though it can be hard to untangle that somewhat from the fact most of them have wide baffles, so presumably they are sending more direct sound towards you which may account for that added size and presence as much as any box resonances.

But one common characteristic among the singing box designs is that I seem to hear the box a bit more, sometimes overt, sometimes really subtle.  They rarely totally disappear as much as the more inert speakers.

I found a comparison between my Harbeth SuperHL5plus speakers and my Thiels quite interesting.  Both have beautiful organic tone.  The Harbeths being known for this.  And the Harbeths sounded rich and full - yet really open and seemed to "disappear" quite well, much better than one would expect looking at them.

But compared to the Thiels, the Harbeths had a sort of texture that ran through and behind everything, even in the space between instruments.
It didn't stick out as obvious box ringing, but when I played the same material on the Thiels, for instance an acoustic guitar quartet, the sound seemed to clean up of any blur on the Thiels.  Instrument tone was essentially as rich, but became even more distinct because of the higher precision in the sound.   All the instruments and their character that much easier to hear.  

My feeling after that (and selling the Harbeths) was that the singing box method certainly can work, but it seems to me that the most likely path to advancement in realism lies in reducing the influence from the speaker cabinet, as most designers are trying to do.

That's not to say that I automatically prefer the super dead cabinet sound.  I've fallen for the Devore O series somewhat for their richness and dynamics and they are not of the dead-box variety.  But I am also a bit more aware of the speaker than I am with speakers like my Thiels which can really be "invisible" as sound sources.