Hi,
No, and I'm not sure if Ian has ever experimented with ribbons. As Tom Tuttle correctly noted, the dispersion of ribbon tweeters is quite different and less consistent than a dome.
Most audiophiles are fascinated with exotic tweeter designs, as indeed I am. There are quite a few types, including planar-magnetic tweeters that use a flat film diaphragm, first used on early Infinity speakers decades ago.
Then there are really exotic ones that use ionized gas, with no moving diaphragm--the Ionovac, Hill Plasmatron, and so on.
It would be fun to compare speakers using exotic tweeters, but in the end, I think it's careful adjustment of tonal balance and smooth even frequency response, control of resonances, plus wide dispersion that makes a great speaker.
Regards,
