[mulveling]

I had ST200 with Kensington SE a few years ago, and now ST100 with Canterbury SE. Amplification with the ST200 was restored vintage PP tube amps in the 25-25W range (Heathkit W5 and Eico HF-87); now it's a high-power KT120 amp (Rogue Apollo).

I always start out liking it for a couple days, then go right back to without. I think Jim Smith is right that it takes extremely careful/precise setup AND a very precise seating/head location for best results. I (and I imagine most other owners) haven't had the tools/patience to get it precisely right. To some degree, I feel that if I don't like what it's doing with a "typical" setup (these are marketed as making a notable improvement in such a setup), then it probably isn't worth the effort to dial in to the micron.

The most noticeable effect is its contribution in the *audible* treble range, where you'll definitely hear more zing and sparkle. You can try to counterbalance this with the crossover settings in the tweeters and on your main speakers (if Prestige models), but the steps on my Kensington/Canterbury crossover are a sledgehammer like 1.5dB (way too big; not a fine gradation); never felt like I could get everything precisely dialed in.

Besides the issues with balancing audible treble energy, the sound with supertweeters can feel tighter and cleaner (this is why I like them at first), but this is at some expense to the musical flow of the speaker...which is probably why you bought big Tannoys in the first place. Also, if you have even a touch too much treble coming from the supertweets, then it's relatively easy to "locate" them apart from your main speakers.

Now when I had a working reel tape deck, the tweets were GREAT with that, but obviously the tape needs help in the upper audible treble range vs. a high quality vinyl source.