What is your favorite material for loudspeakers?

Johnk, the goals of cabinet construction for a string instrument and for a speaker are subtly different. . . a luthier uses the entire case of the instrument as a mechanically active amplifier. . . As such laminates like timber plies make for inferior student instruments because they lack the ability to propagate/amplify mechanical vibrations, not to talk about particle board which simply is anathema in cello/violin construction. The top of a cello is usually made from carved and finely graduated thin spruce. . . the bottom plate from almost equally thin maple or poplar. . . the two are mechanically coupled by an oaken post. . . . then of course there is the coupling to the strings through tailpiece, neck, and elastic maple bridge. The instrument is incredibly light and thin-walled, and vibrates and rings like it's going out of style. I haven't seen too many speakers that attempt to do the same. Hence, invoking the Cremonese masters is effective markcom, but. . . G.

Paino Black with Clear Coat paint.

I have to agree with Eldartford. No cabinet is the best cabinet. I love my stats.

Guidocorona
I suspect you could build a speaker enclosure to operate like a fine string instrument.
You could make one, or perhaps even a matching pair.
There is almost no possible way, for a reasonable amount of money, to mass produce such an instrument.

As for a practical (advisory) perfect enclosure, why not concrete? Heavy and inert, it would add nothing to the sound of the drivers. Add dampening to taste.

I'll stick to my panels.

Cerrot, How is your stat held? By frame metal or wood so is resonates just like a cabinet thus has coloration just like a cabinet. Don't believe place a stethoscope on material holding stat play music.. Also stats can have forward backward movements as membrane moves forward and back this cause planar to rock. Most designs don't fully address this thus all the aftermarket stat stands. And Guidocorona I fully understand the differences in musical instrument construction and loudspeaker cabinets. And a few loudspeaker in the market today have cabinets similar to a musical instrument construction. I don't offer for I feel designs are to colored.