Angelo
To my eyes, this is a fairly horrific acoustic environment - reflective sidewalls very close and with no absorption, and horns firing straight down the room, parallel to the walls, from what I can see. Have you tried aiming them inwards towards the listening position and away from those acoustic mirrors? Did you do your listening experiments with this set up?
Dear Jean-Michel ,
the build of my horns is correct, as anyone can check at my website.
Neither had my S2's any problem , nor the actual Coral M100 i am using now.
I do not question Lynn's listen habilities. Neither do i the merits of LeCleac'h horn profile.Fact that horns can sound like electrostatics can have several meanings. I usually atribute to electrostatics the hability of sounding " transparent ", clean and holographic ( at least that was what caught my attention the few times i had the oportunity to hear them ). Saying that, i had the same impression, when listented Magico Ultimo's in San Francisco, with tractrix horns, and TAD-4003. It sounded amazing : very clean and transparent . During the years i had S2/LeCleac'h horns, i thought i had very natural/neutral tone, and that was the comment also of several visitors, most accostumed to direct radiator speakers. I observed the difference only, and what was possible, once i was exposed to the TPL-150 and direct comparison. I think it has to do with the fact, that our ear acostumes very easily to determined sound. I would have nothing against being proven wrong, Jean-Michel. I do not stick, and i am not biased towards a determined technology/brand/configuration etc. What counts to me , is only, what i enjoy most. I like the learning process, and evolution. One curiosity i have, is to know how horns would behave, small as used in Goto setups , in the 1-5khz frequency range. Since in that range the ear is most sensitive, i think getting that frequency range right is crucial. Have you had the oportunity to listen to the TPL-150 ? I will be in Paris between the 27th of september, and 1th of october. I could bring them with me. It would be a pleasure to meet you, and you could check out on site what it is , that i am talking about, making direct comparisons, and prove me wrong, if that is the case. As you can see on the thread at my forum, i am not alone, many are discovering the superiority of the new breed of air motion transformer based loudspeakers.
Angelo
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That is not my setup, but Tuyen's, from Perth, Australia. My setup, you can see here :
AV Eikon : finished - Page 3 - Audio Voice Acoustics
and here, many examples of setup's, that use the TPL-150 :
Beyma Tpl-150 - Audio Voice Acoustics
Matching the exit angle of the compression driver to the entrance angle of the horn throat is important. The reason that "mix-n-match" compression drivers and horns can give unpredictable results is due to this mismatch. It doesn't help that the exit angle is not usually specified by the manufacturer. I know that the Altec/GPA 288 is between and 7 and 8 degrees because Bjorn Kolbrek carefully measured his 288C's, and there's no reason for Great Plains Audio to change this key construction feature (GPA used to be the official Altec repair facility until the Altec name was sold to Sparkomatic of Taiwan).
I phoned and asked the chief technician at Radian what the exit angle of the 745 was, and the answer was 4 degrees. It's my understanding the new "throatless" JBL's have an exit angle much larger than this, in the range of 20 degrees or more.
If the exit angle is slightly narrower than the entrance to the horn, that's fairly benign, since the acoustic wave expands a bit as it makes the transition from driver to horn. An error in the other direction would be much more serious; there would be a compression "pinch" as the wave was squeezed down from a large exit angle to a smaller entrance angle. This is similar to the diffraction "pinch" of early constant-directivity horns (Manta-Ray, Bi-Radial) and the Altec sectoral horns, which has a disastrous effect on impulse response, as well as creating considerable ripple in the impedance curve.
I have heard - but do not know for certain - the Vitavox S2 is a British variant of the Altec 288 with a small error in the design of the phase plug, which causes ripples in the HF response. The difference in phase-plug may have been done to avoid infringing the worldwide Altec patent, or perhaps Vitavox was a British licensee and just wanted to do the phase plug their own way. In the late Forties and early Fifties, during the Austerity years, the UK had severe restrictions on importing non-Commonwealth technology; the British government was under severe pressure to improve its balance-of-payment situation.
The net result of the immediate postwar restrictions on importing American technology was that domestic UK companies supplied the replacement equipment for UK theaters, and German companies like Klangfilm played a similar role in postwar German theaters. In much of the rest of the world, in nations where there was no domestic equivalent, Altec was the dominant supplier of theater equipment from the 1950s through to the late Seventies, when JBL started encroaching on Altec's traditional markets.
So I am not sure why the phase plug of the Vitavox S2 departs from the Altec original; it might have been to avoid infringing Altec patents, Vitavox might have had their own reasons - who knows. But Vitavox was selling into a protected Commonwealth market, and did not have competition from Altec.
I grew up in Asia (Japan and Hong Kong) during the Fifties and Sixties, and it was all Altec over there, as it was in North America. (When I was in Hong Kong during the Sixties, it was an interesting exception to the Commonwealth preferred-trade zone. HK had free trade (as in zero duty or import tariff) with the rest of the world, as well as the Commonwealth zone, so there was naturally a lot of trans-shipping through the port.)
Returning to the Vitavox or other "unobtanium" collectibles, I'm not interested in designing around components that are only available on the audio-collector market; if a design of mine is successful, that would only result in further bidding-up the price on eBay and the exotic Asian markets. That's a sweet deal for the antique-equipment hoarders, who laugh at the rest of audiophilia, but not so good for anyone else.
Is the Vitavox S2 "better" than the Altec 288? I have no idea. I'm not willing to take another audiophile's world for it, unless I've heard their system and drawn my own conclusions. I've heard the 288, 416, and 515, as well as the Radian and RAAL, and it's a sound I like.
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This may sound arrogant but is certainly not meant that way. It's just that people run up to me and say "you gotta hear this!!!" and drag me into a store or hifi show demo - and, well, disappointment. Most audiophiles have different tastes than I do; I've become resigned to that.
It also means that nearly all equipment reviews are meaningless. I've driven away from $200,000 reviewer's systems and preferred the modest factory radio in my Toyota. The reaction could easily be mutual; only a small minority of audio nuts like direct-heated-triode amplifiers, large-format compression drivers on modern horns, and Altec bass drivers.
JBL throatless drivers have no exit angle per se. I think it should ideally be considered 0°, depending on the exact geometry of the phasing plug.
Hello Angelo,
I don't know the TPL150 but I know quite well other loudspeakers (AMT, Heill...) based on the same principle. I agree they have many qualities but they don't reach the high level of sonic qualities that I need and which ones, at the moment can only be reached using high quality modern compression drivers and horns having very low diffraction.
With such a dipole like the TPL150 or the Heil, you simply cannot achieve what we can describe as a 3D holographic image, what you obtain is a deep and probably wide soundstaging but this is not the 3D holographic image described by Lynn and described by myself many years ago (which requires also for the whole system to be low phase distortion).
I remember that before you choose to use the TPL150 you were using an old Audax 17cm loudspeaker (I hope my memory didn't failed ), a loudspeaker that I know very well since I was a teenager (Audax was a very famous French loudspeaker builder in the 60's). I was puzzled when I hear that you were finding the Audax more naturally sounding that the Vitavox/S2 combo and since that moment I developped a definitive opinion that your listening tastes cannot serve as reference. (But if the sound of your system please you, that's not a problem and I respect that, but it is only an isolated opinion, and also, be sure that Lynn and me are well aware of such psychoacoustical accustomance has you described, to trying to avoid it in multiplying the occasion to listen to as many different systems possible.).
As Lynn wrote : to match the exit angle of the compression driver with the throat of the horn to insure a continuous (1st order and 2nd order) continuity of the profile is needed to avoid diffraction at throat (and High Order Modes in other's language ). But also as you can see in pictures of the Grande Castine set-up (Musique Concrète, Marco Henry), the axis of the left and right horns should not be parallel one to the other but may cross some distance in front the listener (an advice I begun to give 10 years ago I guess). This is also a requirement to obtain the holographic image.
Many people, here in France, that did'nt followed such advices used to give bad opinions of the Le Cléac'h horns, so I am quite accustomed at opinions like of your's. (But to tell the Le Cleac'h horn is couloured when so many give testimony they are the less coloured possible, you should ask yourself what is wrong with such discrepancy between you and the others).
Best regards from Paris, France
Jean-Michel Le Cléac'h
I don't know the TPL150 but I know quite well other loudspeakers (AMT, Heill...) based on the same principle. I agree they have many qualities but they don't reach the high level of sonic qualities that I need and which ones, at the moment can only be reached using high quality modern compression drivers and horns having very low diffraction.
With such a dipole like the TPL150 or the Heil, you simply cannot achieve what we can describe as a 3D holographic image, what you obtain is a deep and probably wide soundstaging but this is not the 3D holographic image described by Lynn and described by myself many years ago (which requires also for the whole system to be low phase distortion).
I remember that before you choose to use the TPL150 you were using an old Audax 17cm loudspeaker (I hope my memory didn't failed ), a loudspeaker that I know very well since I was a teenager (Audax was a very famous French loudspeaker builder in the 60's). I was puzzled when I hear that you were finding the Audax more naturally sounding that the Vitavox/S2 combo and since that moment I developped a definitive opinion that your listening tastes cannot serve as reference. (But if the sound of your system please you, that's not a problem and I respect that, but it is only an isolated opinion, and also, be sure that Lynn and me are well aware of such psychoacoustical accustomance has you described, to trying to avoid it in multiplying the occasion to listen to as many different systems possible.).
As Lynn wrote : to match the exit angle of the compression driver with the throat of the horn to insure a continuous (1st order and 2nd order) continuity of the profile is needed to avoid diffraction at throat (and High Order Modes in other's language ). But also as you can see in pictures of the Grande Castine set-up (Musique Concrète, Marco Henry), the axis of the left and right horns should not be parallel one to the other but may cross some distance in front the listener (an advice I begun to give 10 years ago I guess). This is also a requirement to obtain the holographic image.
Many people, here in France, that did'nt followed such advices used to give bad opinions of the Le Cléac'h horns, so I am quite accustomed at opinions like of your's. (But to tell the Le Cleac'h horn is couloured when so many give testimony they are the less coloured possible, you should ask yourself what is wrong with such discrepancy between you and the others).
Best regards from Paris, France
Jean-Michel Le Cléac'h
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Hello Jean-Michel
if your reference point is the rather antique ESS Heil AMT driver, than i would say, you have no reliable reference-point. There has been made significant progress. The TPL-150 is a entirely different beast.
Well, then what i have is probably better described as wide and deep soundstage ( i actually thought a " 3D holographic image " and " wide and deep soundstage " would describe the same. But that might be just semantics.....
That was a rather premature description of a experiment, i made some time ago. Today , i would say, the Audax does not sound " better ", just different, with its own characteristics and strengths, which are appealing, but since its a entirely different technology ( direct radiating speakers ), its not appropriate to make comparisons. It sounds just different and can appeal more on a emotional moment. But if the only issue is " naturalness" , then i would say yes : It sounds more natural/neutral or correct to my ears, obviously because without horn honk or sort of that. But certainly not more
" precise ", or " distortionfree ", or " clean ", or " dynamic ".
You want to say, the horn channels should be a littlebit inclined , like forming a triangle ? the position of my horn channels are like this.....
I have not said that i disagree, that your horns sound less colored than
other horn profiles. That is actually where i would say relies the merits of LeCleach horn profiles. You have got probably find out the best possible solution . But it gets as far as it gets. And that means, the drawbacks are not entirely eliminated. In my view today, i would say it is probably physically impossible to employ horns in the most critical frequency range, where the ear is most sensible, that is in the midrange, without getting horn colorations in a certain degree. That might be a temporary opinion, until someone or a experiment teaches me better. As said, i would be curious to try a small horn as used in Goto setup's in the 1 - 5khz frequency range, to see if for example voices still sound as coming out of a tube. It is just a guess that this behavior might not happen, and then i would change my opinion. But so far, i keep saying : the Beyma is the best, most natural/neutral sounding mid/high driver i heard so far, it has brought a big improvement in my system, and i do not hesitate to recommend it to anyone that asks for my opinion. Sad you are not open for a update, but that is your choice.
some opinions from others in regard of the Beyma:
Hawthorne Audio • View topic - Silver Iris Reference AMT official thread
I talked with someone in the know who said that a custom pro speaker builder has switched from using TAD horn drivers in his line arrays, the ones used in concert situations, and in now using the Beyma AMT. It just sounds better. That is quite a statement as many have regarded the TAD horn drivers to be the top shelf.
http://www.diyaudio.com/forums/swap...e-any-price-raal-beyma-ae-aurasound-more.html
Beyma TPL150 Air Motion Transformers.
-Initially developed by Oskar Heil, these drivers combine incredible output capability with an insanely linear response, ultra low distortion, a potential 1khz crossover point, and a monopole or dipole radiating characteristic depending upon your preference. It's not too often you'll see a direct radiator spank a compression driver.
The gradual refinement of the horn plan - Page 3
The Beyma TPL-150H may not be a "real" ribbon, but to my ears it sounds truly great - much more natural and relaxed than the compression drivers I have tried so far above 1500Hz.
Hi-End and Hi-Eff loudspeakers system 2
Radiation surface four times the one of a tweeter or an equivalent compression driver, thanks to its folded geometry.
- Mobility transformer of air (Air Motion Transformer) because it causes in the air a speed four times greater than the one of the folds themselves (relation 4:1).
- This confers an enormous dynamics and an incredible transient response, vastly superior to that of any conventional tweeter, including ribbon tweeters and compression drivers.
All these characteristics make of the TPL-150 an authentic alternative to the conventional compression drivers, and contributing an enormous added value to any sound system that incorporates it.
http://forum.speakerplans.com/ribbon...837_page2.html
Look at Beyma TPL150 for an amazing "no compression" driver (different technology than Ribbon but same outlook and much more rugged). The dynamic and clarity without harshness is disturbing at first. Only problem, after some addiction to the TPL, all compression drivers sound crap afterwards...
Hello Angelo,
Since the Rice-Kellog loudspeaker (1924) improvements in loudspeakers proceeded by very small steps and always there was people arguing of "superior performance" of a given design that make all the previous models obsolete.
I cannot see how the improvements done by Beyma, which is a Spanish company more known for their replica of famous PA loudspeakers, could be considered as a revolutionary evolution of the Heill loudspeakers.
I am very suspicious about such claims. In the last years in France we used to have such a buzz about the "Janus" loudspeaker which one was presented by many as a "revolutionary version" of a design made by Paul Paddock. Even it was presented by so called audiophiles as "the best loudspeaker ever". As for your Beyma TPL150 it was said that it was far better than any compression driver + horn. Interested, I went to listen to 3 different systems using those Janus (one of them being a Swiss version of which was sold something like 100.000USD) and also I used to perform some measurements. What resulted from that experience is that the Janus loudspeaker gave a pleasant comfortable sound with a (much) simplified character and no 3D pin-point image but a wide and deep soundstage with long decays of notes and erasing of the rapid transitories. For all the voices, from different records I know well, the differences were drastically reduced between one to the other voice, all the voices sounded nearly the same. I was puzzled that the owners of those systems used to generally consider that a system that sound pleasant whatever the record is bad or good is positive when it should reproduce nothing more than the intrinsic quality of the record IMHO. When I gave a detailed report of my listenings with much details, it was as if I committed a sacrilege! Even I was insulted for that. (Even during a "European triode festival which is private, the main builder-seller of the Janus came to meet me and he tried to apply some pressure on me in order that I admit in public that "I was wrong and this loudspeaker is the best". You can imagine that I am not sensible to such pressure and refuse to continue to discuss with the guy... )
At the moment, anaother buzz is becoming popular : the DML (Distributed Modes Loudspeaker)... Well I really think this will lead to a same quickly vanishing fame...
Best regards from Paris,
Jean-Michel Le Cléac'h
Since the Rice-Kellog loudspeaker (1924) improvements in loudspeakers proceeded by very small steps and always there was people arguing of "superior performance" of a given design that make all the previous models obsolete.
I cannot see how the improvements done by Beyma, which is a Spanish company more known for their replica of famous PA loudspeakers, could be considered as a revolutionary evolution of the Heill loudspeakers.
I am very suspicious about such claims. In the last years in France we used to have such a buzz about the "Janus" loudspeaker which one was presented by many as a "revolutionary version" of a design made by Paul Paddock. Even it was presented by so called audiophiles as "the best loudspeaker ever". As for your Beyma TPL150 it was said that it was far better than any compression driver + horn. Interested, I went to listen to 3 different systems using those Janus (one of them being a Swiss version of which was sold something like 100.000USD) and also I used to perform some measurements. What resulted from that experience is that the Janus loudspeaker gave a pleasant comfortable sound with a (much) simplified character and no 3D pin-point image but a wide and deep soundstage with long decays of notes and erasing of the rapid transitories. For all the voices, from different records I know well, the differences were drastically reduced between one to the other voice, all the voices sounded nearly the same. I was puzzled that the owners of those systems used to generally consider that a system that sound pleasant whatever the record is bad or good is positive when it should reproduce nothing more than the intrinsic quality of the record IMHO. When I gave a detailed report of my listenings with much details, it was as if I committed a sacrilege! Even I was insulted for that. (Even during a "European triode festival which is private, the main builder-seller of the Janus came to meet me and he tried to apply some pressure on me in order that I admit in public that "I was wrong and this loudspeaker is the best". You can imagine that I am not sensible to such pressure and refuse to continue to discuss with the guy... )
At the moment, anaother buzz is becoming popular : the DML (Distributed Modes Loudspeaker)... Well I really think this will lead to a same quickly vanishing fame...
Best regards from Paris,
Jean-Michel Le Cléac'h
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Although it sounds like semantics, it isn't. The two are similar, but not the same. Once you've heard a "holographic" soundstage, you'll remember it. It's such a remarkable illusion that it leaves a lasting impression. Good speakers can do wide , very good speakers can do deep, but few can do pinpoint and fully rounded images. I.E. and instrument or voice is not only located in the X,Y,Z axis but had the correct shape and size - like the rela thing. It's a little hard to describe.
I have no idea if the Beyma driver can or can not do this, it certainly looks like a really good driver. At nearly $500 each, I won't be testing any soon. Tho I know you got a very good price on yours.
hello Jean-Michel
the technical data and explanation at the website i linked to, together with the comments from various people, some very experienced, speak a strong word. When i decided to try them out, i did leave all preconceptions on side, and let my curiosity speak louder. They might not be a technical revolution or innovation, as you say, rather a evolution of a concept known already many years, but thats not what i am looking for anyway. But they have given me many hours of satisfying listening pleasure. Not looking back to compression drivers.....
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Once you've heard a "holographic" soundstage, you'll remember it. It's such a remarkable illusion that it leaves a lasting impression. Good speakers can do wide , very good speakers can do deep, but few can do pinpoint and fully rounded images. I.E. and instrument or voice is not only located in the X,Y,Z axis but had the correct shape and size - like the rela thing. It's a little hard to describe.
I feel very lucky to have had this experience on Pano's system. I've never heard anything like that again, even on extremely good all-horn systems. My own system does things pretty well, except that last thing where you are transported to another place with every recording. Where you can point to the cello that's playing 20 feet behind the front wall. I think Pano's secret is as much in the equipment he uses as it is in the way he sets it up.
First time I heard this effect was with a Nestorovic system 16. The holographic image was just as good 90 degrees off axis as on axis. This was an all direct radiator system and this characteristic was one Mile' sought with every system he designed and we produced. I will never forget that 5'8" black women singing Jazz and Creole..... For those of you with EnABL'd full range drivers, take one channel of the full range portion, in the box, and lay it on a surface with the driver pointing up. Listen to it from about 30deg off axis. This may be your first time too...
Bud
Gee ra7, now I'm embarrassed. Thanks for the kind words. I don't remember exactly what was running while you were here, but it certainly employed some of BudP's terrific transformers.
Buzzforb: I run a pair of Altec VOTT A5. It's a cinema speaker from the mid 20th century. Basically the famous Altec A7, but with a big multi-call horn instead of the smaller sectoral horn you might have seen. When ra7 was here I was running 8 cell, 300Hz horns. Now I'm running 10 cell, 500 Hz horns. Compression drivers are Altec 288 (ferrite) and the woofers are the Altec 416A (Alnico) with the late 16" frames. Fane bullet tweeters come in at about 7500Hz. Passive crossover of my own design. Amp is whatever I'm in the mood for.
Today I finally got a buddy from work to stop by for a listen, he'd been promising for a year. Was anxious to have him listen, as he has great audio perception (and perfect pitch). He was a monitor engineer for a lot of national acts but can still hear. When he left I asked him what he thought.
He said "Well.... usually when I go to listen to something like that I sit and make a list of all the things that are wrong with it. But damn, I couldn't find any." Instead he decided to figure out my crossover points and went up and stuck his head in the woofer and the horn, back and forth. "I can't figure it - 600 Hz or 800Hz?" I laughed. "725 Hz". He now wants to come sleep on my sofa in the music room.
Buzzforb: I run a pair of Altec VOTT A5. It's a cinema speaker from the mid 20th century. Basically the famous Altec A7, but with a big multi-call horn instead of the smaller sectoral horn you might have seen. When ra7 was here I was running 8 cell, 300Hz horns. Now I'm running 10 cell, 500 Hz horns. Compression drivers are Altec 288 (ferrite) and the woofers are the Altec 416A (Alnico) with the late 16" frames. Fane bullet tweeters come in at about 7500Hz. Passive crossover of my own design. Amp is whatever I'm in the mood for.
Today I finally got a buddy from work to stop by for a listen, he'd been promising for a year. Was anxious to have him listen, as he has great audio perception (and perfect pitch). He was a monitor engineer for a lot of national acts but can still hear. When he left I asked him what he thought.
He said "Well.... usually when I go to listen to something like that I sit and make a list of all the things that are wrong with it. But damn, I couldn't find any." Instead he decided to figure out my crossover points and went up and stuck his head in the woofer and the horn, back and forth. "I can't figure it - 600 Hz or 800Hz?" I laughed. "725 Hz". He now wants to come sleep on my sofa in the music room.
What's different from the LTO is that Pano's woofer is front loaded with a big horn. There are several advantages to front-loading the woofer with a horn.
1. More efficiency. You no longer have to pad the upper horns down by 10 or 15 db.
2. It moves the acoustic center of the woofer further back. Makes it easier to design a passive crossover (although, it is still pretty hard to get it right).
3. And finally, it controls directivity to a fairly low frequency. This last one is crucial for getting that holographic imaging, IMO. Not having early reflections in the 100-1000 Hz is key. Most direct radiators in this region are omni and that first reflection from the front wall is always there.
It would be great to see some polars or off axis curves of Pano's system as well as Lynn's.
1. More efficiency. You no longer have to pad the upper horns down by 10 or 15 db.
2. It moves the acoustic center of the woofer further back. Makes it easier to design a passive crossover (although, it is still pretty hard to get it right).
3. And finally, it controls directivity to a fairly low frequency. This last one is crucial for getting that holographic imaging, IMO. Not having early reflections in the 100-1000 Hz is key. Most direct radiators in this region are omni and that first reflection from the front wall is always there.
It would be great to see some polars or off axis curves of Pano's system as well as Lynn's.
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