Paul S wrote:

I can report that the G2Si loses the "glycerin" at 10k with the ML2s….

I concur with this finding. Any ribbon tweeter that I heard has "glycerin" tone but it is because the ribbon mostly crossed too low. I would say that I still head some trace of the "glycerin" at 10K with second order but I have no trace of it at 13K. It would certainly wary from driver to driver but definitely a ribbon sharply closed at 10K sound nothing like a ribbon crossed at 6K. I still do not know what I will end up but I at this point do not worry about the ribbon's alien glycerin tone. Cross ribbon higher and use HF capable MF drivers -  it would be the best solution do not poison system’s sound with the “ribbonninnessththzzz”….

Paul

The entire pattern shrinks and grows geometrically, based upon the physical length of the edge of diaphragm involved. Please understand, this is not just a theoretical idea, I do and have done this process on many different types and sizes of drivers. I even have a basic amount of pattern application that is quite generic and has worked with equal success in all cases.

Please look above, for either the PDF or the link to a published copy and read the white paper for the EnABL process. It discuses the various types of causes for driver induced transient standing waves. There are some standing waves that cannot be treated with this process, but, since the driver engineering revolution two decades ago, there are very few drivers left with this sort of endemic limitation.

So, the pattern is applied with a technical pen, using a scaled pattern based upon the physical sizes involved, for the normally tiny drivers used in high frequency applications.
When the driver sizes scale beyond these pens I use calligraphy pens for their uniform flow rate and variety of sizes. With these simple tools I can treat anything from .5" in diameter dome to an 18" in diameter woofer with the same materials, though the material when used in the technical pens is thinned by a specific amount.
I am only interested in the few thousandths of an inch on any driver surface that comprises the boundary layer. And that few thousandths of an inch does control the rest of the drivers standing wave characteristics. This is really just a matter of having found the proper fulcrum.

I am located in the Seattle area, so we are quite far apart by horseback. UPS and FED EX do a pretty good job of carrying boxes full of speakers back and forth though......

Paul S wrote:

Piezos, anyone?Paul S

I have a local friend of mine lent me PHY TW37 tweeter. It is French-made piezo driver:

http://www.phy-hp.com/English/Products/TW37_E.html

I was running it last night and it was not as horrendous as I was expected. In fact it was almost nice. I do feel some “heaviness” in the sound of this driver, perhaps because it has fixed 12db/octave filter at 10kHz (too low for me) of because it users a relatively heavy paper cone. Also, the topmost region is kind of “dullish” to be a tweeter. I would feel more comfortable to use this driver as a “lower HF tweeter” then the “all-around tweeter”. I think that the “heaviness” in this tweet might be also because it futures a cone that sits in the moth of a little horn-like… horn and effectively acts as a reentry horn. The “horn-like horn” is filled with cotton that does absorb the highest frequency but should be less absorbent for lower knee of the HF.

Anyhow, dispute of everything, form this French-made piezo driver sounded more balanced then I expected. The biggest problem, in my case, was that this tweeter does have a deferent sound with my Vitavox S2 driver. If with Linaeum/TAD PT-R9 ribbons I might set them in a way that a deference between S2 and Linaeum/TAD PT-R9 would not be acknowledgeable then with PHY TW37 I was not able to do so It is not only about the fixed crossover point of the TW37 but rather different ability to be accelerated with dynamic and frequency range between this tweeter and my MF driver. All of this creates a different “feeling” of Sound…

Stull, the ribbons so far are leading the race…

Vitavox S2 does OK up to 12.5K ("strong, clean and in character") on it’s center but I never use this driver pointed directly to me but rather at good 20 degree off. (I hardly can tolerate any compression driver point directly to me). At my angle the S2 in my 400Hz horn is well attenuated, more civilized and behaves more or less appropriately. In my listening position S2 does approximately 10K but the numbers are kind of meaningless in there as the HF “transient feel” is still there. In fact juts with S2 and no tweeter is it VERY much listenable, I do not know how to explain it though. Any tweeter, of any topology that I’ve used, if I set it to 10-11K made everything too bright. Or better I would not say “too bright” but rather “too unnecessary” as it screw with the “S2’s transient phantom presents”. I feel that in the world of HF it is not exactly about measurements (at least to me) but rather to dial-in the exact necessary amount of HF’s touch – juts a very-very slight inflection atop and it is it. The S2 is not Altec and not JBL and it does not need “help with HF” but rather “a complement of HF”. I do not know now other people but when I try to add HF to S2 driver I always have problems with the fact that I drive a tweeter at so low level that it is become not effective at all. In any case, it is relay hard to describe it as it need to be heard to understand how it works. When I turn volume control on my dedicated separate Milq that drives now tweeters and when I set this volume at the level when I feel it is “enough” then my RTA shows many-many db down at 12K (and my instrumental microphone is well calibrated). I never had a tweeter that I would be able to listen at -3dB at 12K. Anyhow, I hope ribbons would help me to fix this tendency…. if it need to be fixed…

Paul S wrote:

I am glad to hear that I am not the only one who is overwhelmed by compression drivers.  I tried the A7s way back when they were current and everyone's favorite, and I tried various modifications with like-minded friends; but I came to the conclusion that the only way to do the horn thing would be with theater-type "dedicated" amps driving narrow band horns that did not really load down into their horns.  It was just too much for me at the time, and I lost interest in the horns.  And now you say that you still have to listen well off axis...

In fact Altec drivers are too soft anyhow. The real secret in this (people juts do not get it) is to make the properly operating horn line-array, properly ingrate them and balance the entire sound, allowing the off axis equalization (particularly with phase plug drivers)…  But it would be a subject for other thread...

Paul S wrote:

I know one can't be certain in advance, but the way you describe your high frequency wants, it sounds like a perfect fit for either a small ribbon or a small 'stat, or an array of either. A lone ribbon may actually have some horizontal dispersion, but the electrostatic panel really benefits from the array, which eliminates that beam-y quality and that stupid in-and-out thing when you move you head at all.  I hate that!

I was thinking about the electrostats for years. I hate how they sound and I think that heard a lot of them. The problem is that to do the electrostats properly - direct couple them to 3kV plate - it juts too much work to do for a driver the will be covering 1/3 octaves…

Paul S wrote:

And I will say again that I'm not in this for DIY; I really would just buy everything if I thought I could wind up with what I wanted that way!

It is EXECLY how I feel. If I have somebody to whom I would pay to renders my requirements then I would never bother to educate myself on the subject HOW it might be done. Somebody who “can” is loosing a lot of money not to having my phone number in his phonebook.

Well,

I still do not know what the tweeter solution would be. I know exactly what I want to get: to soften the S2 driver and get HF extension but without introducing HF noise. I know exactly how it should sound I juts do not know at this point how it might be accomplished. Generally HF is a big problem as usually in “common audio” the present of HF is recognized by presents of the HF noise (99% of speaker out there). When Audio Morons hear a playback without the HF noise then they complain the there is no HF been reproduced.

Anyhow, the EnABL treated freaky Linaeums driver does fine but with it’s low sensitively it are hardly useable.  The ribbons do also very nice integration with S2 and I will continue to look in this direction, perhaps making a small array if I could sign in a good ribbon maker or find a ribbons with sufficient size of the magnets and flexible and light enough ribbon.

I will continue trying different tweeter solutions, however, the biggest accomplishment of this entire journey was that I eventually recognized WHY a horn tweeter should not be a HF transducer…

The more I conceptualize my view about tweeters the more I like sound of my playback without it. The last night there was a San Francisco broadcast with estimable Tilson Thomas on podium and I was shocked with stunning SFO’s tone. As many times I head that orchestra it never was so reach and so “stuffed” with noble sound. Then it hit me that I have no tweeters and it was perhaps why…. The last night I drive the HF channel of my Super Milq very hard (50mA hotter then usually) and used not tweeters. It was THE sound.

It is imposable just to turn down tweeters and listen as a LOT is gone with tweeters off. However, it is necessary to learn to listening playback with tweets off in order to make sure that a playback is cable to be musical and fulfilling … without tweeters.  What tweeters do in such case? Or more important: how to introduce HF space without introducing the Moronic and non-existing HF into music?

The answer is still pending. I started recently a very interesting project dedicated to making a conceptually “better’ tweeter. I do not know where it will bring me and if it will be the solution but I am have learned that it is much better do not have any tweeter at all then to have improperly performing tweeters. How a tweeter performs what it performs improperly? If you hear HF then you have a crappy tweeter. Welcome to the club…

I put a couple days ago a silk dome tweeter in the game.  I look in my storages to see what I had there among the traditional silk domes. I ended up pulling out my North Creek Music D25 driver.

http://www.goodsoundclub.com/pdf/NorthD25.pdf

I generally like the silk dome tweeters. They very forgiving and generally well balanced. So I decided to try.

Melquiades defiantly was not able to drive it up to reasonable sound quality.  I always with irony was reading the BS-articles of the idiots-reviewers who where drooling about sound of the teens watts SETs (Lamm ML2 for instance) driving sun 90dB sensitive speakers. As well I never understood why people go for SETs amp if they use speakers with sensitivity in 90s. Anyhow, the Lamm M1.1 was driving the North tweeter… with second and third order at 11kHz to 13 kHz…

Generally I liked what I heard. Wide, low ambience noise, accurate and very non-abusive. However there were also tow things that pretty much disqualified this tweeter from the game.

1) Own glassy tone. It has very accurate HF but those FH sound like they are made from grave-stone. Pretend you are blinded and you drink wine and then somebody instead of wine give you a distil water. It is exactly how D25 sounds in comparing to the Vitavox S2’s HF. Do not take me wrong – there was nothing wrong with D25 tone – there was juts no tone at all that might be considered tone. It was more like a soup without salt, paper, species, meat, fish or vegetables. It was a soup that was made by boiling a home Depot’s hammer for 3 hours…

2) Dynamic and it all that I can say. When I played my playback loud, and I like to do it (because I can) then when the music jump into ffff  then the tweeters dived into quite auditable distortions…. Very unpleasant… and I do not think that it was the Lamm M1.1’s fault.

So, the silk dome was exportable not it. I would need something with 20dB more sensitivity…

The Heil AMT drivers are well known in audio. There is a cult of people who follow them and they swear that Heil drivers are like nothing else. The Heil drivers were made by ESS, by Scandinavian, by German’s pro audio and by Russians. The do use deferent principle for sound reproduction (I will not describe it – it well described out there) and do have different type of sound.

http://www.goodsoundclub.com/pdf/heil.pdf

I experimented with Heil in beginning of 2000s and although I saw a lot of very interesting and useful sonic characteristics in Heil I did found them absolutely unusable for any more or less serious application. Nevertheless, since I’m nowadays in my typically-crazy “tweeter mode” I decided to give to the Heil one more try.

I had two Heils. One pair is very small that I took for some kind of speaker 15 years ago. Another pair is the largest AMT-1A, takes from the biggest ESS. The smallest Heils sounded very dead form all dimensions and has sensitively at sub 80dB level.  The biggest Heils were the matter of the different conversation.

Heil Air Motion Transducers sound very interesting. They remove any defects of HF reproduction out of Sound. Even time misalignments, overly bright microphones or HF clipping become practical not annoying. They literary problem free and very addictive solution for many nasty thing in HF. The biggest Heil is 100dB sensitive and it is approximately what I got from them. Melquiades drove them well at ~8K crossover.

Nevertheless, listening the Heil for a few seconds I instantaneously recalled the feelings that made me to discard them for the first time. The problems are that Heil makes all HF to sound absolutely alike. Heil has own very specific “generic HF signature” and it inescapably inject this signature to absolutely any HF note that Heil tries to reproduce. The very same “common Heil HF denominator” is getting created in each single tone of ANY orchestra, in each single inflection in EACH single, in each musical instrument and it become superbly annoying. As soon I “got” a reference to this tone then it so followed me that there were not other options then to trash the tweeter.

I think the problems is the in the Heil transducer has ribbons that are cocooned into a plastic “waved envelops”  (Polyethylene initially and Mylar later on) and I feel that this creates the Heil signatures. The ribbons are not shaking free but the “handled by” the plastic wrappers that severely colors sound by with that “commonly honey” influence. It is not surprise that cleanness of this plastic wrapper or even smoking in the room severely affect the performance of the Hail tweeter.

Can a driver that produces a “Generic HF” be used for audio installations where the purpose of playback is to make audio to “discriminate the differences”?  The answer is very obvious…

I was playing today with Stage Acompany SA 8535 Ribbon driver. It is truly 103dB sensitive little monster with crazily large 3 poll Neodymium magnet. I did listen the driver and there are some things that I like in it and there are some that I do not. I will not comment about the sound of this driver as this point (will do it later) as I would like to spend more time with it. However, juts looking at the design of the driver I can see that there is a lot in it could be made better for the sake of my specific application.

The driver does not look as pure ribbon but rather an array or ribbons (with impedance of 12R, no transformer) enveloped in some kind of plastic. Then this plastic is damped on it’s back with some sort of felt. The driver has very large back chamber, way larger then I deed for over 12K tweeter and the chamber in additionally damped. All of it could be done differently for my HF-only application and I did try to lower the size of the back chamber – it did sound better.

Generally I have good impression about the driver but they designed it to use from 2kHz and with higher power… Let see how the sucker will behave in a few days…

I was keep listening my Dutch-made SA8535 tweeter.  There is a lot of deferent with this tweeter and I think it is a good time to pass my early observations about the tweeter Sound.

This driver is not a ribbon tweeter as the Stage Acompany fraudulently claims but rather an isodynamic tweeter. But who care what it is - the sound of this thing is more important.

First experiments with this driver indicted that it hugely affected by the type and the slope of crossover - in fact it is more sensitive to it then any other tweeters I have seen. It does have a good tone and clean with no colorations HF.  It does have good sensitivity and dose very well with low power Melquiades. It behaves very very good, practically perfect, when it stressed and when it operates at higher volumes. It maintains very flat impedance and it very easy load for Melquiades. It does sound compatible with Vitavox S2 when it is directly on axe. It does go very high and it is not juts bogus numbers the manufactures love to publish but it is actually quite auditable. Also while it runs high and clean it does it very reasonably, without unnecessary accents or enunciations.

Something that I do not like. The driver foam bumps near the exit of the  “ribbons” that meant to accommodate the Stage Acompany’s own horns. I do not use the horn, as I do not need any LF extension, but still did not remove the foam “borders”. I presume that the “borders” severely screwed this driver’s ability to sound wide. It sounds well exactly at axe but literally 20-30 degree on right or left it develops a LOT of HF noise and very unpleasant “fuzzy HF fatness”. Another thing that I do not like that it is too much wiling to dive into MF – I need a high order crossover to hold it. Also, the SA8535 does not have that HF delicacy that I observe in TAD PT-R9 driver. The PT-R9 driver by 100W has delicacy and refinement, sophistication and classiness. No one other tweeter that I tried recently has this level of noble stylishness. The SA8535 does not have it. The SA8535’s highs are colorations-free but they lack of certain gracefulness, charm, distinction and fineness. They are very good on their own but they are not as good as they “might be”. PT-R9 has this fineness, Linaeum is perfectly balanced but does not go where “it” would be critical and the SA8535 dose “it” …strangely….

The SA8535 has some kind of own way to sound and I really could not put it in worlds. What I feel with it this the driver make some of the HF not really “recognizable”. I men when any other driver I heard goes up my inner-me anticipate “something”. This “something” to one or other degree get fulfilled or expected. With the SA8535, while I was listening music I was very frequency catching myself that sometime in HF happened some kind of events that I never heard nether in reproduced sound nor live sound. It is important to note that those “alien events” were not necessary bad – but they were “alien events for my listening consciousness. It was like scratching a cat’s belly and then suddenly detect that it has
A sharp metal object hidden inside her fur… Unexpected? More then just that!

Still, I would like to spend a little more with this driver as it is the first of my “high sensitively success” driver. Definably when a sensitively of tweeter does up then there is a LOT of very interesting things going on with our listening awareness. It is relay nothing could beat a clean tweeter at very high sensitively driven by no-feedback SET. I will open a little a veil of secrecy and will tell you that a truly ribbon driver that is being made for me will have ~ 112dB sensitivity. I do not know hoe it will sound but the SA8535 clearly indicate that the more dB per watt the merrier results are.

I left the SA8535 burning for entire day and nigh, driving it with HF “torture” signals.  Interesting that the driver become much more civilized with those “alien sounds” completely evaporated. Honestly it become to sound much better… but at the same time much …softer. It does perfectly mate now with S2 but since it slowly breaks in it moves toward the soft side. I do at this point to have the SA8535 to be a little more “contrasty”, but very-very little …Perhaps I need when it will be fully “cooked” play again with crossover and slope…

Still, it turning that the SA8535 become to sound like a very good tweeter. Ad to it a little delicacy and refinement and it will be completely perfect. Who know, perhaps I will be able dig in the minor satellites of the SA8535 operation and get more gracefulness out it. If to cross the TAD’ PT-R9’s tone and refinement with SA8535’s sensitivity, ability to care stress and dynamic capacity then it would be a perfect tweeter for my case.