The Shure V15 V with a Jico SAS/B stylus VS The Soundsmith Hyperion MR and Lyra Atlas SL

It looks like my Prompts over the past year+ to a friend, encouraging them to revisit experiencing their owned Audax HD-3P Gold Dome Piezo Tweeter, has paid off, as when I went to the friends today to Drop off my Technics SP10 MK II Kaneta Design TT as a Long Term Loan. I was informed in advance there was a little surprise experience for myself to encounter.

It wasn't the Multi Tonearm Mountable P'holz Plinth for the SP10 MK II, which I am eagerly awaiting to experience, which will have enabled the experience using all the TA's that have been lined up to compare to each other, to be pencilled in as a date to occur.

What was in use as the surprise, is the individuals Speaker Design using the Audax HD-3P Gold Dome Piezo Tweeter.

After about an Hour of Listening to a selection of known to me tracks and a few new encounter tracks, I can say the HD-P3 is as impressive in this system as it has proven to be in my own.

For a reason I care not to try and understand, I'm just very happy to be present.  The Speaker using this Tweeter has the ability to immerse a listener into the music, the sound being produced has the capability to captivate ones full attention for the music being produced.   

I remain content with my assessment this Tweeter might be one the Best Produced Tweeters and it is a shame the design issue it developed was not sorted and it was kept in production.

The owner of the Speakers listened to today has made it known modern Parts used on the electronics will enable a much more expansive Soundstage, and the Xover is to be modified to a up to date design, using PC Triple C Wire within the Cabinet. It is hard to believe more is suspected to be able to be extracted in relation to the sound already being so impressive.    

I have learnt today the intent of the friend as a result of their impression oof the HD-3P, is to produce a OB with a Driver Array that will fully compliment the HD-3P, it has also been voiced that as there is a collection of the HD-3P Tweeters, a Dipole Array could be used for these.

The friend has also made it known that they are now seeing the time to take on the Kaneta Design SP10 MK II, with a much more dedicated commitment.

Hopefully something might happen with the TA Comparisons across the Xmas Hol's, where a Kaneta Design TT is the TT design selected for the comparisons?     

What speaker is being augmented by the piezoelectric tweeter?

@dogberry 

"Not really a problem if you obey the instruction manual that says to use (an) amp(s) of 40-100W power and no more. As you may recall, I have replaced all the panels in my 2905s, and while the older panels were short on glue, it was the case that one would fail and start to arc after playing too loudly."

I still have four out of twelve panels in their original condition.  The rest have been reglued (really much more than that as it involves new mylar and new slightly conductive coating, plus proper tensioning).  Panel failures have been revealed by a slight murmuring noise, or popping as a spark flies!  I have also had a high voltage failure in one speaker - the high voltage is on the same circuit board as audio.  In the end, I made up a piggyback board to produce 5.25-kV.

Initially I used a Quad 405-2 100-Watt amp, basically designed for the speaker.  Later I switched to a lower power amp, the Krell KSA-80.  Well, lower power when measured into 8-Ohms, at just 80-Watts RMS.  The Krell is about 9 times larger, but only 4 times heavier, than the Quad, which made 100,000 405-2 amplifiers, on top of 64,000 405 ones.

In my experience, transients tend to be faster on SACD, BluRay audio and 4K disks, for example West Side Story, Spielberg fashion. Any instantaneous input voltage over 56-V triggers the protection, regardless of amplifier power.  The Krell has an impressive slew rate!

@bdp24 

A couple of obvious issues apart from those @mijostyn has pointed out.

1.  They have two drivers offset spatially by a considerable horizontal distance, which will give rise to comb interference with frequencies in the crossover region

2.  They have a crossover!

The result according to the video is that they are very hard to position.  Coincident source speakers tend to be very tolerant of room positions, and have much larger listening sweet areas ...

Dear @mijostyn  : I really like ELS and especially Sounlabs and Eminet Technologies even that the faster transients where MUSIC comes developed is through horns, yes as everything has trde-offs at both frequency extremes but in its specific frequency range ( depend of manufaturers and models. ) ESL just can't beats it and yes : as always seated at near field position..

Why I don't own horns yet? because its agresivity that many times surpass the liove MUSIC natural agresivity.

Acapella top of the line is a ery good blend of different speaker drivers and really good and expensive ones.

R.