Unsound - I believe that the wavy driver completely eliminates lobing at its cross point, leaving only the lower cross point to lobe. And the 3.7 lower point is so low that beaming is quite minimal, so the on and off axis response is effectively very similar, leaving only on axis ear height as a constraint, which is easily solvable - sit on a couch or easy chair. The flat wavy disc practically solves the hollow tweeter launch environment. Can you tell that I’m a fan?
My main reason for addressing the older models is due to their geriatric needs, the large quantities, and the greater room for improvement.