SUPER TWEETERS-anybody heard them?

Here in the UK -there are two main manufacturers of independant super tweeters (i.e attach themselves to existing speakers-these are by Tannoy and Townshend)-anybody on Audiogon any experience on going down this route?
I don't think anyone can hear a supertweeter.
They must be good then....
I have owned and used both the Sequerra and Apature super tweeters. The biggest benefit was with electostatics that rolled off in the top octave, but even with conventional speakers there was a noticible difference, though it would be a value judgement to say that the difference was an improvement. There are several possible explanations. First the built in crossovers have finite slopes so even a crossover with a 15K 3db down point, which is quite higher than my experience, is down only 15db at 7K if the slope is 12db per octave. This is clearly within the audible range. Second, beats, or difference frequencies can be generated through wave interferance in air and on the diaphragm. IE a 22K and a 23K tone will have a difference frequency of 1K, again within the audible range. Finally, I cannot site the source but I recently read an article indicating that there may be a response to frequencies as high as 50K in humans. I might also point out that in conventionally decoded redbook CD there ain't anything up there. In LP, analog tape and the new digital formats there is the capability of recording ultrasonic sounds.
I just sold a pair of Radio Shack Super Tweeters on E-Bay. Hardly used them. I had them hooked up to a pair of AR-90's because they were lacking high end definition. I realized upon upgrading to Carver separates that the receiver I was using was underpowered.

The sense of hearing is remarkable. I don't know what is my present upper frequency range, but at one point although I could not hear a 15Kc tone (pure sine wave), I could very plainly hear the effect of a 15Kc HF filter on broad spectrum sound. I think that I could have sensed an even higher frequency filter, but that was the highest one available in my electronics. I found this interesting, and formulated the following theory.

The difference between a 15Kc sine wave and a 15Kc square wave is the presence of higher harmonics. The sinewave vs squarewave difference in sound can be sensed even if the harmonics responsible for the difference would, by themselves, be inaudible. I think that the ear senses the rate of change of pressure, which can be high for a low frequency signal if the signal is not sinusoidal.

So, to address the question, I don't think most people can hear a supertweeter (higher than 20Kc) but I do think that they can sense its effect.
Not to side-track the thread, but in response to Czbbcl's comments about his AR 90's being "soft" on the extreme top end, these speakers are relatively linear out to appr 23 KHz. Some tweeters marketed at "super" tweeters won't even go this high. As you've noted, these speakers need GOBS of power to work their best. My experience is that if you can feed them with a real 350+ wpc @ 4 ohms, your starting to get close to what you really need : ) Sean
I have a pair of Rumata ES-103A supertweeters on top of my Wilson Watts3-Puppy 2 and they sound beautiful. The ultimate test in my view is when I dis-connected them from the main loudspeakers, I felt something is missing from the music; hence it justifies their existence, at least in my system.
Although the supertweeters don't really extend the frequency response as such as others had mentioned that our human ear is incapable of hearing beyond about 17kHz. But soncially they seem to make the mid-to-high frequencies just that little bit more tactile, a little more immediate (intimate ?). Someone descibe it as like the sparkles one gets with jewellery/gem stones under halogen light. You owe it to yourself to try a pair to see (hear) whether it works for you or not.
By the way supertweeters been around for a long time; apparently even before the existence of proper tweeters! A lot of them can still be found on those washing-machine sized JBL Studio monitors such as the 4300 series. The Japanese audiophiles love them till this date ever since they were launched in the 60s/70s or even earlier. Now, that said something....
I used to own the Tannoys, used them to add to some Lowther-based speakers I used.

They sounded great, and really did a nice smooth job extending the Lowthers. I crossed them over at around 16kHz, I can't remember the exact frequency. I used them for a while, then sold them. I found that, while they were very good, I didn't NEED them. I put up with the missing extra air and sparkle, but still enjoyed themusic immensely.

My recommendation: if you have a pretty good system now, it may not be worth the extra money. If you can find them used, go for it; you can always try and sell them later for little or no loss.

Good luck
I have a pair of Tannoy ST50 supertweeters on my Verity Parsifals and absoultely love them. Suprisingly, the imrovements are not so much in terms of added sparkle (although the treble does seem to extend higher up and seems more delicate and nuanced) but an overall sense of liquidity in the sound. The transients are also cleaner and quicker. A definite improvement, well worth the (steep) price.

The super tweeters I used were rated to 40kHz. But you are correct when feed with enough power they are very nice and obviously do not need the super tweeters. I still have them with no plans to part with them. I do need to buy new woofers for them though.

I just checked out information on the Tannoy supertweeters, and was surprised by the high price. Considering that you can get a decent tweeter that goes to 20Kc for $100 or less, why should it cost so much more to extend to 30 or 40 Kc?

Seems to me that piezoelectric technology is perfectly suited to this application, and piezoelectric supertweeters are made. Their low cost may be an embarassment, but do they do the job?
Piezo tweeters can really extend response for very little money. The big problem is that current execution of the technology completely throws away phase response. These are among the least phase coherent drivers on the market. They also have a bad name due to the terrible sounding ones made by Motorolla. They can be heard in, among others, the Dayton-Wright XG-8 series and venerable Dahlquisdt DQ-10.
Viridian...thanks for the info. I figure the wavelength of a 30Kc signal to be less than 1/2 inch. Even if the Piezo driver were perfect regarding phase, how could one ever get it time-aligned with the other drivers of the system? Maybe the phase problem isn't important.

If I were to try out a Piezo, is there one brand that you would suggest? I would just hide it behind my MG1.6 speaker, and bounce its sound off the ceiling.
There seems to be a related effect at the other extreme also which has been noted with RELs Sub design. Even though we do not actually hear the effect there are things happening below both thresholds of 20-20K.

Here is a dialog taken with the REL Designer.Sorry this is getting away from the question,but both extremes should be explored I thought. Having true intergration must be addressed using either exterme I imagine.If not I would think there would be unwanted overhang which would muddle up te effect or benefit of using a either a Super Tweeter or Sub-Sub Woofer!
This is to answer to a question I think sbg had about the article I had alluded to in a thread about Bass Reproduction with subs. The initial question I had was why most speakers that were on the market could not have the kind of extension I would want .Another words Full Range for an affordable price. There are a few exceptions like speakers from VMPS. This is the article I had mentioned.It was from ABS not S-phile.

If it was not sbg then excuse the reference to him.
The Absolute Sound –Feb.\Mar. Issue P.73 of the Kharma Ceramique Ref. Monitor 3.2 review by JonathanValin

Putting aside enclosure and room-mode issues, with a large multi-way you are confronted with the problem of trying to make drivers of unequal size ,mass and material composition sound like one unit. Though crossovers are theoretically designed to do just that, anyone who has ever yoked subs to an electrostat or good mini-monitor can tell you that what’s true in theory is not true in fact. Just listen critically to the midrange of any such speaker before and after you’ve added subs.I don’t care what sub it is or what slope or filter you apply; you’re going to losse something in the way of soundstaging, transparency, dynamic speed, dynamic speed and nuance, and inner detail—in short, you’ll lose a significant amount of what you bought the the speaker for.(Of course you gain something , too,in the way of body ,midbass authority, instramental weight, and low bass extension but let’s not pretend that these things don’t come at a cost that some of us are unwilling to pay)
Regarding Low Frequency...In any large hall used for recording there is a very low frequency rumble that is always present even when the musicians have gone out to lunch. It represents the natural frequency of the hall, and is excited by such things as the air conditioning system and passing road trafic. This subsonic noise is plainly audible on some recordings if you have suitable speakers and you don't activate your rumble filter.

But is it "noise"... something undesirable. It can be argued that this "hall sound" is part of the musical experience, and reproducing it adds to the realism of the recording. I find that is true for some recordings and not for others, probably depending on how severe the background rumble is.
If you had read the links which I provided I think there were comments related to tings like the hall or room effects that occur in recording studio's.

The point that was being made from discussion was that there is info that does happen at both extreme's that does influence mood or perceptions.

I think threre was a review by by Anthony Cordesman that also reflects this point wehn reviewing the new KEF's which also use a Super Tweeter.

There just might be an undercurrent that pulls you into the music that we do not acctually hear.
Sequerra HF 1's...I sit them on whatever speakers I the DQ10's, ELECTROSTATS LIKE MY DAYTON WRIGHTS etc....other people's speakers AND THEY ALWAYS ADDED "AIR" AND A BIGGER, DEEPER, TALLER PRESENTATION....ALWAYS!


I also have a pair of the Tannoy supertweets and like them a lot: the soundstage became deeper, everything sounds smoother and cleaner. They definately help.