I've been grousing about the lack of low bass in expensive speakers. My expectations when paying 5 or 6 digits for a loudspeaker would start with full range and go up from there. Such is not the case.
But one positive thing I have observed is the cabinet and just how much attention is paid.
The perfect speaker cabinet adds nothing. Place a set of drivers in a cement wall and you'd get close to what we're hoping for—the vibrating drivers don't excite the cabinet.
Most expensive loudspeakers handle this wonderfully and it is one of the central reasons they sound extraordinary in the frequency range where they work. Like Magico, YG Acoustic, Wilson Audio, lavish attention to detail on cabinetry pays off in spades. You can break a knuckle testing rigidity.
Lower cost speakers do their best with bracing, varying densities of materials, clever architecture. But they're not inert and you can hear the difference.
The greatest contribution a speaker cabinet has to make is nothing.