Hi Ken,
Thanks for your interesting views on tweeters.
I'm just wondering if you've had the change to listen to the Magico S7 or S5 Mk2's modified diamond-coated BE tweeter? And if so, how did it rate against the other tweeters you mentioned?
Btw, slightly

fftopic:, but from my auditions of various high end speakers over the years, this would be my list of the best tweeters i've ever heard -
1/ Acapella High Violin which uses a horn-loaded Ion tweeter with no mass. Incredibly fast with seemingly unlimited dynamics. It is the best tweeter i've ever heard, and blended well with the horn-loaded midrange. Thought it should be noted the High Violins had bass integration issues due to the incredibly fast tweeter & midrange.
2/ Crystal Arabesque which uses a custom version of the superb RAAL 140-15D ribbon tweeter. This tweeter sounds incredibly natural, smooth, fast and has wide bandwidth & excellent off-axis response. Gabi has also done a great job of integrating the RAAl tweeter with the custom
Scan-Speak Illuminator bass/midrange drivers
3/ Magico S7's which use a MBD26 diamond-coated BE tweeter. Combined with the new 6" graphene-carbon Nanotube midrange & integrated midrange enclosure; the sound is completely seamless as Mike described, with excellent resolution, balance & sense of 'ease' which allows the music to flow. The S5 Mk2's MB7 diamond-coated BE tweeter should have similar performance.
4/ Infinity High Energy Emit which is a planar-magnetic ribbon tweeter. This newer tweeter was used in the classic Renaissance 80 & 90, IRS-Sigma, Omega & Epsilon models. Having heard my friend's Ren 90's, I was amazed how fast, smooth & resolving this tweeter was & how well it blended with the High Energy Emim midrange. In particular the Ren 90's had excellent off-axis performance & threw a wide, holographic soundstage.
Side note: I would expect the 28mm Diamond-coated BE tweeter used in the Magico M Project & Q7 MkII to be better than the S5 Mk2 & S7, and likely one of the best tweeters in the world, but I haven't heard those models.
Cheers,
Tom