I dont want to spoil yoir illusions...
But what "flat" drivers are you referring to?
Are they driven uniformly over their entire radiating surface?
(Another point of fact, conventional flat drivers, are not driven uniformly, as a ribbon is...
That includes ESLs, planar magnetics - much optimisation is required to even approach a perfectly uniform distribution of EMF or Electrostatic charge.)
The simplicity of a simple conductor such as a ribbon, makes the challenge of uniformity very much easier, and it becomes only a challenge in magnetic flux uniformity, and not EMF/Electrostatic uniformity, in addition.
Think about it.
The points made regarding magnetic field uniformity, are certainly valid, but these challenges exist for ALL drivers, excluding ESLs and plasmas.
Bending modes too...i agree.
But then we dont have, bell modes, rocking modes, break up modes, non uniform drive.
A ribbon eliminates many mechanisms that are flaws of conventional electro dynamic systems - this is not to say, it does not have mechanical flaws inherent to it's own construction, but they are fewer.
And in my opinion, the flaws are more benign.
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Hi, ScottG
Most TRUE ribbon drivers have a very light moving mass, but what about the strength of the motor? Can you show me a ribbon tweeter that has over 1.5+ Tesla in the gap ? The ability of controlling the moving mass is just as important as the actual moving mass. I have or have owned some of the best ribbon drivers on the planet and none compare (in my experience) with top compression drivers, IN MY SYSTEM. In my particular case, the TAD ET-703, has come out the top of the heap !! There is a reason why these tweeters demand $2K++ used, if you can find a pair !! It is a real shame these tweeters have been discontinued. Of course, your particular speaker system and tweeter demands will dictate what is best.
Most TRUE ribbon drivers have a very light moving mass, but what about the strength of the motor? Can you show me a ribbon tweeter that has over 1.5+ Tesla in the gap ? The ability of controlling the moving mass is just as important as the actual moving mass. I have or have owned some of the best ribbon drivers on the planet and none compare (in my experience) with top compression drivers, IN MY SYSTEM. In my particular case, the TAD ET-703, has come out the top of the heap !! There is a reason why these tweeters demand $2K++ used, if you can find a pair !! It is a real shame these tweeters have been discontinued. Of course, your particular speaker system and tweeter demands will dictate what is best.
Several mylar ribbon foil high units, along them the famous Technics TH800 and the Philips varieties had to be extensively tested with various damping materials in the magnetic gap, before they started to measure reasonably flat and distortion-free. This was quite well known when these came available.
Well the Founteks I use, formerly Dynavox, seems to have had that sorted.
The manufacturers frequency responses, Polars etc are all easy to find on tinterweb.
As are the 3rd party measurements, CSD, frequency response etc, which show the "warts" that I am aware of, I.e. the cavity resonance and poor THD at between 1kHz and 2kHz.
Luckily for me, I did the ground work, and found these things out, at the outset, and worked with them.
Certainly, they best all of the tweeters I have used to date, within the same bounds of usable bandwidth and flatness of response.
All anecdotal, but nevertheless, it's good enough for me
(The only Phillip's "ribbons" I have heard, are the so called devices on my Phillip's Microsystem - which are actually magnaplanars. They're OK, for such a system, but not high end, by any means)
Anecdotally, I have never heard any Phillip's speaker, that didnt sound like gash.
The manufacturers frequency responses, Polars etc are all easy to find on tinterweb.
As are the 3rd party measurements, CSD, frequency response etc, which show the "warts" that I am aware of, I.e. the cavity resonance and poor THD at between 1kHz and 2kHz.
Luckily for me, I did the ground work, and found these things out, at the outset, and worked with them.
Certainly, they best all of the tweeters I have used to date, within the same bounds of usable bandwidth and flatness of response.
All anecdotal, but nevertheless, it's good enough for me
(The only Phillip's "ribbons" I have heard, are the so called devices on my Phillip's Microsystem - which are actually magnaplanars. They're OK, for such a system, but not high end, by any means)
Anecdotally, I have never heard any Phillip's speaker, that didnt sound like gash.
Philips once built very decent drive units that could compete with anything else in the market then. The company left the business of consumer electronics in the nineties though. After the compact cassette and the compact disc, that is...
"Mylar ribbon foil" tweeters are not the same thing as a "pure" ribbon tweeter which is being discussed and generally (although ambiguously) called a ribbon tweeter. Don't confuse the two.
The diaphragm in a ribbon tweeter like the AC G2 is a pure, very thin (0.01mm) corrugated aluminium foil. (Or aluminum for the Americans among you 🙂 )
100% of the diaphragm is conductive metal and this means the entire diaphragm is directly controlled by the magnetic field interaction.
A "ribbon" tweeter using Mylar has a thin mylar film typically with a layer of metallic foil or very fine wires bound to it or printed onto it. As the Mylar is an insulator it is not under direct control of the magnetic field and is just "along for the ride" in the same way a cone or dome attached to a voice coil is. Breakup modes can and do occur due to the interaction between the metallic voice coil component and the Mylar diaphragm which does most of the moving of air.
While superficially similar these two different types of ribbon tweeter have very different performance characteristics and can't be treated as equivalent.
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Philips built many very good driver units from the 60's until the mid 80's (my Dad built many speakers in those years using Philips drivers, some of which are still in use today) and then quietly walked away from the market altogether.
They also did a lot of basic research on acoustics and transducer design and published many reference books on the subject of speaker and crossover design.
Pity - they walked away from many other fields as well - in the 70's and 80's they made some top notch oscilloscopes and a lot of other test equipment, but I don't believe they make any of that stuff anymore either...
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DBMandrake,
I admit using the term ribbon to apply to all ribbon structures, be they pure foil, laminated foil, corrugated or not.
The Fountek I use are, IF I am correct, a laminated foil, not vapour deposit film conductor, nor a pleated foil.
So I guess despite being driven across its while surface, the BL factor would be reduced, and fragility also reduced. I imagine.
I admit using the term ribbon to apply to all ribbon structures, be they pure foil, laminated foil, corrugated or not.
The Fountek I use are, IF I am correct, a laminated foil, not vapour deposit film conductor, nor a pleated foil.
So I guess despite being driven across its while surface, the BL factor would be reduced, and fragility also reduced. I imagine.
IIRC the nonlinearities were caused by the tension of the membrane. On ribbons vs magnetostats vs electrostats vs mylar foil vs AMT’s I am aware of the differences. Fact is that all have their merits and cons. We’ve not yet been discussing the step-down transformers needed for the Decca like types 😉
Anyway, there’s another place on this forum for planars and the like... speaking of which, Charlie Laub performed measurements on a few contemporary units lately. Not impressing, if I may say so. Just to stress that quality often is in the execution, not in the principle.
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Actually most motors in ribbons (that are at least 94 db) are very strong (some use n52 bar magnets), but because of the design very little force gets applied to the ribbon. It's a wide gap, and not much of the ribbon near the gap when compared to a convential design. My guess that Bl is under 1 for most ribbons. 😱
I've not heard the 703, only the JBL 2405 (..and for TAD the 2001 in a very small horn covering super-tweeter-only range). Both sounded artificial to me: a bit "zippy" with sound that was artificially "fast" but lacked decay. 🙁
I had thought of using the fostex ft96h at one point (because of it's very wide dispersion), but never did. 😱
BTW, plasma's are still the best high freq. driver I've heard: they don't have much of a "sound" at all except for the dispersion pattern. I always wanted to hear a 360 plasma tweeter - that would likely be my "best of best". 😎
Actually most of the rest of the world pronounces as Aluminum. ..seems Aluminium is mostly for people who drive on the wrong side of the road. 😀
The non-reinforced pleated designs (that measure worse) often have the best sounding decay character at very higher freq.s. To much damping factor though and it can sound "whispy". It also doesn't have much mass for any appreciable "force" character that some crave.
Basically if you've got a small good SET amp. hooked up to a good pleated ribbon then you are likely enjoying at least part of the audible spectrum that 99.99999% will never have heard to that level of quality. 🙁
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Aluminum is the American and Canadian spelling for the silver-white metallic element (number 13 on the periodic table) abundant in the earth’s crust.
Aluminium is the preferred spelling outside North America. Neither term is superior to the other, and both are etymologically and logically justifiable. Aluminum is older, while aluminium is more consistent with other element names such as helium, lithium, magnesium, and so on (though let’s not forget there are other -um elements—molybdenum, tantalum, and platinum).
Aluminium has the edge in scientific writing even in North America. This is primarily because several influential scientific organizations and publications prefer the spelling.
Aluminium is the preferred spelling outside North America. Neither term is superior to the other, and both are etymologically and logically justifiable. Aluminum is older, while aluminium is more consistent with other element names such as helium, lithium, magnesium, and so on (though let’s not forget there are other -um elements—molybdenum, tantalum, and platinum).
Aluminium has the edge in scientific writing even in North America. This is primarily because several influential scientific organizations and publications prefer the spelling.
Hi, Scott
I have heard the Acapella plasma tweeters several times at audio shows over the years and almost bought a pair. These tweeters sound excellent but come with their own unique problems. They are very inefficient and do not play very loud ( compared to a good compression driver ) without distorting. The efficiency was low to mid 90's and not a good match for my system. I had a plasma tweet built for me by a friend using an 813 power tube, sounded great, but the ozone generation was very unhealthy after 20 minutes of playing !!! There are also maintenance issues, very expensive, and a possible fire hazard. No young kids playing around these babies !!!
acapella ion TW 1S plasma tweeter measurment and impression
I have heard the Acapella plasma tweeters several times at audio shows over the years and almost bought a pair. These tweeters sound excellent but come with their own unique problems. They are very inefficient and do not play very loud ( compared to a good compression driver ) without distorting. The efficiency was low to mid 90's and not a good match for my system. I had a plasma tweet built for me by a friend using an 813 power tube, sounded great, but the ozone generation was very unhealthy after 20 minutes of playing !!! There are also maintenance issues, very expensive, and a possible fire hazard. No young kids playing around these babies !!!
acapella ion TW 1S plasma tweeter measurment and impression
-it's probably also the preferred pronunciation. 😱
I've heard a few Germans (when discussing CNC manufacturing and materials) use the North American pronunciation - but they were likely pandering to the American in front of the camera. 😀
Of course it doesn't really matter. I personally like the sound of Aluminium's pronunciation better, but it's just to obtuse to say it like that when compared to Aluminum. Brevity in communication is a really nice bonus (..where comprehension is paramount).
..when speaking to an audiophile listening to plasma tweeters:
"say, I know your white - but you look REALLY white, like Dracula white". 😀
Helium use or catalytic conversion is the more "commercial" route for plasma tweeters.
you'll laugh, but I have a foam matress, a thick one. makes a pretty decent early floor reflection. but then thats hard to integrate in a living room lol
Nope. It's pretty much only North America which uses Aluminum. Every other English speaking country uses Aluminium.
That should probably be some good drivers. I uses a lot of them and many were mediocre.
dave
Well said.....and I share your observations and conclusions....there’s a dare is repeat ‘subjective’ experience with a ribbon......which I theorize is a result of the weight of the membrane.
Nowadays with recent improvements to full range type drivers, the available of “suitable’ drivers to cross to a ribbon are much better......the well regarded Scanspeak 10F would be an most acceptable candidate.....but there are suitable less expensive options as well.
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