Are exotic speaker cabinet materials overrated?

@bartsw   then where is the resonance of a grand piano or cello going to come from, the room, the wall behind you? 

Not sure what your asking. The piano has a sounding board that amplifies the sound from the vibrating stings. Same as the cello resonating from the stings. These are instruments designed to PRODUCE sound. Has nothing to do with the room or back walls. The speaker box does NOT have the same function. It produces nothing. If it does that's bad.

there's such as thing as an alive speakers vs a dead speaker.

There is??? Can you give me an example of a speaker that's "alive" vs one that's "dead" ?

This is correct...

• Reduces Vibration & Resonance: A rigid, well-damped cabinet prevents the box itself from vibrating and distorting the sound, leading to clearer audio.

Hello hiendmmoe!  If speaker cabinets are builtf rom acoustically inert materials, they are great. I have been building small and larger cabintes for 15 yeqrs or so. You want stone coutertops such as used in kitcher remodels. Broken counter tops are available from fabricators of such things at very low cost. You won't have a choice of colors or size, but visit a few shops and you'll have what you need in a few weeks. They will cut them to size for you if you don't want to invest in a diamond saw. They are used to making precision cuts. I use silicone rubber to glue the pieces together. Front panels are plywwod and MDF sandwhiches. The backs can be mostly coutertop material cut 6" short to allow for MDF panels for mounting speaker terminals. If you think you will need access to the interior, use rubber weather stripping instead of glue under the lip of the top slab. Gravity will hold it down airtight. You can lift the top off whenever you wish. Enjoy the music.

P.S. Open baffles sound better and much easier to move.

http://scaena.com/speakers.html

I notice no boxy coloration with each driver enclosed in special ceramic compound. Thomas

Manufactures have been switching to lighter, thinner enclosure materials which makes lots of sense when they include the costs to ship their speakers to vendors or drop ship them to customers. They've taken advances copied from the British to make enclosure resonances consonant with those generate buy the drivers while they're reproducing music. The British took this approach because the BBC needed monitors to be light weight and mobile for onsite field applications.

Realistically in the home environment enclosure resonances aren't as important or obvious under most circumstances as listeners want to believe. Instead, engineers design them with heavier and more ridged materials or radiuses where they're needed, lightweight braces in strategic locations and in addition specifically placed damping materials along encloser walls (bitumen or tar) where they've detected uncontrolled resonances during the development phase.