Thanks, painttoad.

One problem with ribbons is that their dispersion characteristics (cylindrical) are sufficiently different from conventional drivers (spherical) that its dificult to mix and match ribbon driver-based speakers with others. The exception is, of course, within a single speaker, and even this is arguably difficult -- some audiophiles maintain it is not possible to do it well enough, and reject hybrid speakers as possible "high end" contenders for this reason. These same audiophiles purchase silver speaker cable at $250+ a foot, I suspect.

So, it's either an all ribbon system (as far as midrange-high frequencies go), or an all-conventional one.

I've found that both the Carver ALS and the Radia 520i are crossed at a relatively insensitive point that they work well as two-way speakers. Of course, the Carver ALS, with three 12" woofers each are clearly full-range speakers, whereas the 520i are not. IIRC, the Carvers will do 108 dB at 1 meter at 18 Hz, though I would not want to drive them that hard as a matter of course (nor risk foundation damage).

In my case, in a room with a flat drywall ceiling and hardwood floors, the cylindrical dispersion pattern counteracts the natural "brightness" well. Room treatments could have the same effect, of course. But, in the end, after some 20 years, I've become fond of ribbon drivers.