Super tweeter for FullRange Driver


I have a pair of Audio Nirvana 15in Alinco Classics that I just got done getting into cabinets. After some listening impressions, I've realized I cant live with the high frequency response these things put out by themselves. They only go to about 15k hz. and it's made music lose its sparkle and sense of space and spacial cues. I was thinking of buying a pair of Fostek T90As and pointing them at the ceiling for a more even dispersion and better integration with the Audio Nirvana driver. My main question is what  capacitor volume would you suggest? Where in the frequency response would you crossover to the tweeter? Would wiring the 8ohm tweeter and the 8ohm Audio Nirvana in parallel make me need to change my amp(Audio Note Kit 1 300b Set) from 8ohm to 4ohms? Any other brands of tweeters recommended for a fullrange driver that is around 96bd efficent? Sorry for all the questions, incredibly new to trying to implement crossovers with full rangers. If this sounds like a bad idea. Please speak up. 
akwilson501

Those tweeters are banned from import to the US. Ozone factories.


Really!!! someone better tell these guys they’re breaking the law, as these Lansche speakers also use Plasma tweeters, even though they are horn loaded and directional to get the db levels, the Magnat MP-02 are better, no horn and have a 360’ radiation pattern.

https://www.theabsolutesound.com/articles/lansche-audio-no7-loudspeaker/

https://www.stereophile.com/content/lansche-audio-51-loudspeaker

https://www.lansche-audio.com/p-series/


Nelson Pass on plasma tweeters
As Nelson Pass said of his massless “ion-cloud loudspeaker” described in the sidebar “[the speaker] gave new meaning to the word ‘transparency.’” And so it was with the Lansche Audio No.7. This loudspeaker’s midrange and treble reproduction was absolutely sensational, and different from that of conventional loudspeakers, whether cone, electrostatic, or ribbon. The Lansche simply disappears as a sound source, not just spatially (which it, along with many other great loudspeakers, does), but also mechanically. By that I mean the physicality of the loudspeaker’s operation—the mechanism by which is creates sound— disappears, replaced by the physicality of the instrument it is reproducing. It’s the kind of sound that produces a “fool-you” realism of timbre, as well as “fool-you” palpability and immediacy. There was an ethereal character to the sound, as though the music existed independently of any electro-mechanical contrivance—“conjured out of thin air” to use Jonathan Valin’s wonderful description.

Absolute Sound on them
The treble had the wonderful quality of being highly resolved without sounding bright. The No.7’s reproduction of cymbals, and of brushes on snares, was revelatory. The corona-plasma tweeter beautifully resolved the transient detail of the stick hitting the cymbal, the shimmer that changes character slightly as it decays, and then revealed the finest inner detail at the end of the decay. This lack of smearing of fine transient detail was spectacular and alone worth the price of admission. When combined with the top- end openness and transparency, this treble resolution produced a stunningly lifelike feeling of actually being in the same room as the instrument.

This is why I said my Magnat's doing highs, are like fireflys dancing in 3d space in front of you.

Cheers George
I’m using enigmacoustics sopraninios permanently charged electrostatic supertweeters to goo effect, if they are in your price range .  
I appreciate the feedback from everybody. Why I would love to try both the magnats and the enigmacoustics, I'm going to work with some fostex t90a's at first to see if I like what they add. If so, I will upgrade at somepoint, so thanks for the advice on those. I'm trying to cross my tweeter over around 15khz, wouldn't a .33uf capacitor be ideal, in a 1st order filter? Considering the 106 db on the fostex, and the 96db for the fullrange.
ENIGM Acoustics Sopranino electrostatic supertweeter

Never seen these before. Wow! killer load for an amp, like most esl’s in the highs.
https://www.stereophile.com/images/614EnSopfig1.jpg

"Sopranino’s magnitude increases with decreasing frequency. However, with the 8kHz filter setting, there is a very high inductive phase angle between 7 and 12kHz, a region where the impedance magnitude drops to less than 2 ohms. This makes the Sopranino very difficult to drive at this setting"
Cheers George