I heard the demonstration of the EnigmAcoustics Sopranino on top of Magico V3s at the California Audio Show and it was a nice improvement to the sound. We played a track without the super tweeter and then with it, and back again - did this on 4 or 5 different songs. Very nice indeed.http://stereotimes.com/post/enigmaacoustics-electrostatic-super-tweeter/
This is by no means a cheap item.
Here's is a link to an inexpensive product, from China I believe - Taket. Certainly cheap enough to try it out and see if it works for you before you spend big $.
I own the Townsend Super Tweeters. They add that little bit of extra air to the performance.
I have Tannoy ST100 on top of Esotar tweeter in modified Merlin VSM. Highly recommended. I suggest the version with the lower 14, 16, and 18kHz crossover points. This allows the roll-off to extend into the more audible mid-treble range if need be.
The Townsend ribbon Super tweeters that Ozzy mentions are widely praised. I know that I want a pair.
you may also look " home" for some JBL 2405 and with 2uF cap in series you can hear what it is all about.....
Super tweeters need to be design for particular loudspeaker used not just off the shelf one size fits all. More to it than just setting a box on your loudspeakers and saying good enough if you understand how they interact with the rest of the loudspeaker you would know I speak the truth. But posting such isn't what you all want to hear so it will be ignored. Forum posters want someone to agree that what there doing is right and generally only consider posts that agree to be of use. Sometimes I wonder why I bother so happy listening slap that ST on top its all good.
To begin with, a lot of these supertweeters do have adjustments on them, and since you are only augmenting the highest frequencies that are likely not even being produced by your speakers tweeter, it is not like you were adding a "super midrange" (if such a thing existed) which would cause all sorts of problems obviously.
In the end, many have found them beneficial to the whole sonic spectrum, and if that conflicts with measurements that say it shouldn't be so, who really cares, except apparently yourself.
I think that these super tweeters are helpful to the aging population of hi-fi hobbyists. As we age (50+) we loose some high freq. hearing ability. These ST replace what we are loosing, and we like it. We should all set up our systems the way we like them. If we then tire of it, we change it. If you strive to maintain perfectly flat response and end up with a perfectly "flat" sounding system, you will probably start to explore areas of improvement for yourself.
Can cause destructive interference due to to far a distance between drivers and from drivers covering some of the same frequency not to mention the time error. Then you have the very limited efficiency of most ST again not going to match your loudspeaker unless both are designed as a whole. A driver doesn't allow you to hear ranges your not capable of hearing if they could there would be no hearing problems for one could just use a aid and wow you hear normal doesn't work like that. Last I post good luck.
One thing I like about Tannoy ST100/200 is eight selectable crossover points and sensitivity settings. In my application this made them a much better match than the Chinese Lucy ribbons. Correct time alignment can be obtained by varying front-to-back positioning on top of the main speaker. I mount them on an elevated platform to decouple from vibrations across the top of the cabinet.
An ST placed in parallel with the main speaker will change the impedance load on the amplifier. This may effect which amp impedance tap sounds best-- assuming that your amp has the flexibility of multiple taps.
Be aware that whatever cross-over point and sensitivity level is selected, there will be downward embellishment all through the treble region. Tannoy uses a third-order crossover. Their manual includes frequency plots.
Bottom line, the ST is a tool I would not want to be without.
From JohnK - "A driver doesn't allow you to hear ranges your not capable of hearing if they could there would be no hearing problems for one could just use a aid and wow you hear normal doesn't work like that."
What I'm saying is that the super tweeter is the aid. It's helping listeners with high frequency roll-off due to age. It's not like being deaf, where no driver is going to make you suddenly hear. Rather, it boosts up the areas where we are becoming weak in our hearing.
JohnK is correct in his statements though. It's very unlikely that the placement of a super tweeter is going to be time aligned to the regular tweeter as well as the effects from two drivers far apart. This is all true and should be considered upon utilizing such a thing. It is a tradeoff, but most users probably realize this and allow the added/needed boost of highs to outweigh the negative timing and phase effects. Certainly our rooms play a much larger roll in negatively affecting the elusive "flat response" then an added tweeter.
That is true, but there are ways to compensate for that as well. In my case, my speakers are a D'Appolito arrangement with a large horn between two woofers. If I had a super tweeter, I would build a stand for it so that it was level with the mid horn, and placed farther back to compensate for the earlier arrival. There are options if you use a little imagination.