| Air Motion Transformers (Heil's) and New Diaphragms - Click HERE for Original Thread |
| EchoWars |
I have had a pair of ESS Heil AMT's for many, many years. My latest speaker incarnation of them has them biamped with a couple of Dynaudio 20W75 in each cabinet (original woofers and cabs tossed out years ago...)
Anyway, my current AMT's have diaphrams that I bought back in about '82 or so. They have worked wonderful over the years and do not need replacing. However, I have found two much newer AMT's (the big ones, Great Heil's, as the ESS tech's call them) that have no diaphrams. I'd like to tackle another project with new AMT's but I am hesitant...
On another forum someone said that the new diaphrams that ESS sells are ****. More power handling, but bad rolloff after 10KHz. Seems odd to me. :scratch: These diaphrams are supposedly mylar or something.
I guess what I want to know is...who has heard the newer style of diaphram that ESS is now selling? Was I simply being ********ted about how bad they are? How do thay sound to you?? |
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| EchoWars |
I know there are guys in here that have experiance with the newer Heil's, so.......
--bump-- |
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| halojoy |
I think you have got a point. ;)
But all new things are not better,
but some really are.
So, I guess it could be done either way.
I am not sure, but ....
/halo - not quite sure but almost |
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| SY |
| Here's a simple check- see if you can get diaphragm mass or thickness specs from the seller for the replacement parts. Compare it with what you've got. If it's substantially the same, you probably aren't going to have some mysterious HF rolloff. New diaphragms DO need to be worked in before frequency response comparisons should be made. |
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| AMT-freak |
@EchoWars, thanks for your reply in my transistor replacement thread ;)
My AMT I are about 10 years old and I never had to replace diaphragms, but a friend of mine managed to damage one of his AMTs three years ago. He ordered two replacement diaphragms directly from ESS and first replaced only the damaged one to compare the sound of old and new. As far as I recall it, there were of course differences, but they were subtle and acceptable as his AMTs were also quite old. He then replaced the other one too and let them "burn in" a while. He still likes them and I account the only differences between the sound of mine and his mainly to his electronics. |
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| Nelson Pass |
As I recall the original Heil diaphragms were polyethylene,
not Mylar or Teflon. These later materials were tougher,
but never sounded as good.
The original, best sounding material was made from the
packaging material for airline peanuts, and may still be
in use in the food packaging industry. |
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| EchoWars |
Indeed, at one point I was told by ESS what my 'veiled' diaphrams were made of, but have long since forgotten. Hate to shell out $100 US to see if the newer ones are worth it, but perhaps that is what I may have to do.
As an aside, I can't imagine what it would take to smoke a Heil diaphram, besides some catastrophic amp failure. They get so loud with so little amp power that one would certainly have to be doing something stupid. I have used and abused mine for over 20 years, and they are still ruler-straight and sound like new, yet I have seen many Heil's on eBay with diaphrams that looked like they had been dragged behind a car... |
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| AMT-freak |
Overloading them is easier if you lower your crossover frequency. ;)
/ AMT-Freak - enjoys his Heil's down to 800 Hz in a two-way setup |
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| EchoWars |
Indeed, I have a two way setup here also, but crossing them at about 2.3KHz, simply because the Dynaudio 20W75's do such a nice job up to that point...
800Hz. Wow... :bigeyes: |
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| tomtt |
audio mart (on stateline rd in kcmo)was selling heils with
a pair of gauss 15"z ,x'ed at 800hz with cabnet in late 70s
demo-ed with supertramp's, 'school'
pant leg flappen good. |
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| EchoWars |
I had a buddy who worked there in the late 70's. He is actually the one who suggested I get the studio monitors that they had after he put a couple of the small Heil's into his AMC Pacer. Sounded great, I was hooked. Bought the Heil's and have considered my midrange and high-end covered ever since, though I have gone through many versions of woofers trying to find a match...
Have crossed mine over at a variety of freq's, and the Dynaudio/Heil combo sounds best letting the Dynaudio's do the work up to 2300 or so (it should, the Dynaudio's were hella expensive).
///kinda suprised anyone remembers Audio Mart from back in the day... |
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| tomtt |
maybe yor buddy did the demo for me
did you see the rtr 25"woofers at mcgee
radio?
seemes like they were 225 each,1986 |
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| EchoWars |
RTR woofers? Hmmm...by 1986 I was in Boise, ID. In the 70's the only decent woofers McGee had were Eminence, and they left a bit to be desired.
My buddy was Steve Galpin(sp?) Used to play in a local band, and I ran their sound. He was drummer, about 5'10'' or so, a bodybuilder, and a cool guy. Always wondered what happened to him... |
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| planet10 |
| quote: | Originally posted by AMT-freak
AMT-Freak - enjoys his Heil's down to 800 Hz in a two-way setup |
What kind of XO are you usig? I'm looking for a (temporary i hope) passive design somewhere between 800-1.2k.
dave |
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| AMT-freak |
I was browsing the forum for some information on magnet material in my AMTs just to discover someone asked me a question about my speakers!
Hope you don't mind me taking about a year to reply: ;)
It's an active 24db Linkwitz-Riley XO since the woofers I'm using are great until about 800 Hz but have a large peak soon after 1 kHz, so... Also helps to reduce the load on the AMTs. Finding a low frequency counterpart for these tweeters is a tough job and I've seen many bad sounding speakers (including the original ESS). Having tried many expensive drivers I think you should definitely go two-way and let the AMTs play as low as possible.
Now for something completely different:
Does anybody happen to know what magnets they used in the old AMT-1 (the big ones)? I can only measure dimensions, but what about the material? |
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| RAWDON |
i want to obtain a set of replacement diaphrams for my 1980 vintage ESS AMT MONITORS...WHERE IS THE BEST PLACE TO OBTAIN THEM..have just had the bass units and PASSIVE radiators overhauled..after 25 years of use...
please help someone..
Steve Rawdon
Wellington
New Zealand |
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| Raoul |
Not sure if this is the BEST place to purchase them, but it is A place...
http://cgi.ebay.com/ws/eBayISAPI.dl...ssPageName=WD1V
Hope the link works. If not, search ebay for "heil diaphragm". By the way, I have never used them and do not have any information on the differences between the various incarnations of the heil diaphragms. It is a source, though... |
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| RAWDON |
i have just obtained a replacement set of d/phragms from the west coast of the states and they sound just like the originals in my 1980 AMT'S from ESS..I obtained them as spares to my original that still work fine..(all are teflon/mylar units..I cant tell any difference in sound quality..
Steve in nz |
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| EchoWars |
| Good to know Steve...thanks!! |
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| Magnetar |
| I replaced the old soft diaphagms with the 'new and improved' mylar disasters - the new diaphragms sound terrible in comparison. They have a yellow tint to them and are not soft but hard and brittle - just like they sound. |
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| RAWDON |
| mine are the same as the originals...black and white..no yellow tinge..I tried them out..they sound just like the originals which are still in use...tks for the post..cheers steve |
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| pooge |
| who did you buy them from? |
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| RAWDON |
how do you mean they sound terrible...does the material feel soft compared to you old diaphragms or sound soft ..can you please give me more details and which model speaker are you using..the yellow colour should make no difference..
Steve |
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| RAWDON |
| hi pooge..I bought them from Orange County Spekaers |
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| Urloony |
I'm glad I found this thread. Please forgive my newbieness, but I had just a couple questions.
I have a pair of heil tweeters, but unfortunately only have one of the original woofers. The cabinets seem to have been custom made as they are unfinished and transmission line construction. The volume of the box is about 1.2 cubic feet.
I was hoping you guys might have some ideas about what drivers to use in the box as replacements for the originals as well as crossover recomendation. I'm now using a radio shack special crossed at 2K.
The tweeters do not have a tone control. Is there a way to build one? Or is it not necessary. They do sound a little bright.
My last question is whether the impedance of most ESS Heil systems was 4 or 8 ohms or did they produce both?
any opinions appreciated |
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| hornaudio |
I have a number of Big Heils, as they are called by ESS, old and new. My spectrum analyser indicates:
The old diaphrams (silver looking) made on soft poly have a frequency response of 500 to 18K +- 1 db. The new diaphrams (yellowish looking) and made of a stiff material (kapton?) have a frequency resopne of 800 to 9k +- 3db.
I think they must have converted around 1999.
Big difference!
You can make great new diaphrams yourself. see Speaker Builder 2/1977 |
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| cdfr |
About the diaphragm Great Heil replacements. I suggest that you get it from ESS itself: http://www.essspeakers.com/
The guys are nice and the service and price are fine. I have mad quite a few purchase from them.
I have a 1973 AMT1b and a 1994 AMT1E Monitor. I must say that for me the Kapton diaphragm (yellow) sound fine. The original one its true were physically softer but sound wise I cannot say that there's been a degradation.
This latest model was tested by the guys at "Prestige Haute Fidelite" and they were as impressed as they were back when the Gret Heil came out.
Any one tried to make a Heil speaker using JBL bass drivers, may be even K2 drivers (2x 12 or 1x 15 inch)?
CD |
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| cdfr |
| Just to illustrate here is the graphs from Prestige Haute Fidelite |
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| cdfr |
| Now a picture of the famous diaphragms |
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| cdfr |
| and a picture of my AMT1E Monitors with 2 Heils |
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| markp |
| What is the physical pattern of the layout on the heil diaphram? |
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| tomtt |
Originally posted by cdfr
Any one tried to make a Heil speaker using JBL bass drivers, may be even K2 drivers (2x 12 or 1x 15 inch)?
CD
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seen and felt Heils, with Gauss woofers,
and plenty of power, a real eye opener!
as in post #10 in this tread
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JBL's should work quite well
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Bart Locanthi worked at JBL and Gauss( and pioneer and Altec)
he may well be the father of the modern
low frequency loudspeaker- |
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| palomino77 |
| I have a pair of speakers M122 by ESS, I bought back in 1980 and like them very much. Recently I took out the woofers to get re-coned, the trouble started after I had take the woofers out,,, I checked the Heil’s to see how they sounded and turned up the volume until they started whistling,,, I turned down the volume and didn’t try them again until I put the woofers back in hoping I did not blow them out,,,, but I guess I did something wrong because now, every time I turn up the volume to about 10:30 on my dial even if their is no music or sound whatsoever they start to whistle, so I must have done something to them. They still sound great until they start to whistle,, I’ve had them for 26 years now and never had that problem before, is there something I can do? My amp is a pioneer SA -8800 non switching 80 watt continuous power per channel 1980:xeye: |
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| badman |
| quote: | Originally posted by hornaudio
I have a number of Big Heils, as they are called by ESS, old and new. My spectrum analyser indicates:
The old diaphrams (silver looking) made on soft poly have a frequency response of 500 to 18K +- 1 db. The new diaphrams (yellowish looking) and made of a stiff material (kapton?) have a frequency resopne of 800 to 9k +- 3db.
I think they must have converted around 1999.
Big difference!
You can make great new diaphrams yourself. see Speaker Builder 2/1977 |
For those of us who don't have a 30 year archive of speaker builder, can you describe how you do them? |
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| dshortt9 |
| My understanding is that the newer Kapton ones extend to 30 khz. Would also like instructions on "winding my own." |
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| badman |
Has anyone else actually measured the current drivers/ribbon (yellow mylar)? The 800-9k number seems very brutal :bigeyes: , making the driver almost useless, for those of us who can actually hear above 9k ;)
Do we know if the french magazine was measuring the mylar ones? |
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| dshortt9 |
| Hornaudio - your spectrum analyzer must be broken. There is no way these only go to 9k. Please provide supporting evidence. Here is a pic of my homebuilt speakers with yellow ribbons and the tweets are amazingly good and extended. |
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| badman |
I've got a buddy who's sending me some of the old style, so I'll be able to compare. I'm working on a test baffle with 2 Audax PR17OMO, open baffle, with the heils. 15" on the bottom, crossed over at... some point. First order for the heils and audaxes at 2.5k- they'll each extend an octave with a first order filter, then plummet like a brick (just what I want!) so I get a moderate overlap area but retain first order filters hooray!
So when I get that all together, I'll test the two heil ribbon types.
*edit* Plummet like a brick: the heils roll off pretty severely below 1k from what I've seen, and at 2.5k the audax start beaming pretty good, so the off axis response is what I'm referring to in their instance. |
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| Neil Davis |
| quote: | Originally posted by hornaudio
You can make great new diaphrams yourself. see Speaker Builder 2/1977 |
| quote: | Originally posted by badman
For those of us who don't have a 30 year archive of speaker builder, can you describe how you do them? |
There was a follow-up to the article that described an easier method using etchant and drafting layout tape. Still not a very easy process, and it doesn't make sense to make them if you can buy the diaphragms at a reasonable price. However, the results can be good.
The homebrew diaphragms will start to get brittle after about 10years, but I'm not convinced the brittleness causes any deterioration in the audio quality except at low frequencies. The kapton diaphragms should perform well between 1K-20K--that is the material that A.R.T. uses and their measurements don't agree with what others here have reported.
I've wondered whether the tweeter in the picture was the largest Heil ever made...
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| studervox |
Hi
I have one old new stock pair Heil to buy by
http://www.essspeakers.com/
This is a good deal.
In 2 way system (very fine) the best low speaker is a Altec 420 A
Regards |
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| Terry Demol |
| quote: | Originally posted by badman
Has anyone else actually measured the current drivers/ribbon (yellow mylar)? The 800-9k number seems very brutal :bigeyes: , making the driver almost useless, for those of us who can actually hear above 9k ;)
Do we know if the french magazine was measuring the mylar ones? |
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| Terry Demol |
| quote: | Originally posted by Terry Demol
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Wasn't sure if that would come out. Yellow diaphragms, from memory
one of the plots was 2 stacked vertically and the other just one.
This is the later style thicker (3mm) lamination Heil.
As you can see they certainly do go past 20k.
We also tried sonic comparison of the older (soft clear) diaphragms
versus the newer yellow ones and the new ones were cleaner
sounding, but they both had their own slight character.
I have them ruunning with Altec 414c 12" alnico MB driver and
it's one of the few drivers that work with Heil.
cheers
terry |
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| badman |
| quote: | Originally posted by Terry Demol
As you can see they certainly do go past 20k.
terry |
Thanks! It's confirmed! |
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| tomtt |
| quote: | Originally posted by EchoWars
In the 70's the only decent woofers McGee had were Eminence, and they left a bit to be desired.
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they had many, many things (woofers) that they did not always
have in the catalog.
truly thousands!
listen to what were said to be a original, and a replacment
diaphram, seemed to be no diff- |
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| cdfr |
In this same post I attached the measures done with the later version of the Great Heil with Yellow cartrige and as you can see the measures are very good.
Post #28
http://www.diyaudio.com/forums/show...0521#post670521
I have had the 3 versions of the cartrige, the original "soft" from 1972, the clear version from 1994, and the last Yellow version.
There are no issues with the yellow version, they sound fine and go up to 20K no issues.
cheers. |
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| Braggi |
Greetings Heil AMT fans. I've had my Concept CE-Monitors (Pacific Stereo house brand made by ESS) since 1976. I'm still on the original diaphragms which sound like new even though they have suffered much use and occasional abuse. Since this thread began long ago many changes have taken place. Replacement diaphragms for original AMTs are no longer available from Orange County Speaker or elsewhere. The assets of ESS have been bought up by a German company now producing speaker systems costing $12,000 or more. Drivers can be purchased from a German Web based company for $690 Euros each (not a typo) plus shipping. Diaphragms do not appear to be available from this company. Oskar Heil's family founded a company in Switzerland also making an "improved" version of the AMT with systems costing $7,000 and up.
Those of us with vintage AMTs are out of luck if we need replacement diaphragms.
With that in mind I have begun the process of building my own diaphragms. I have purchased mylar in two thicknesses I'm planning on trying. I realize ESS started using teflon near the end of their time in Sacramento, but I can't figure out why, where they bought the teflon, or how they got their adhesives to stick. Teflon is a challenge to work with.
Quote from Nelson Pass in this thread from long ago:
As I recall the original Heil diaphragms were polyethylene,
not Mylar or Teflon. These later materials were tougher,
but never sounded as good.
The original, best sounding material was made from the
packaging material for airline peanuts, and may still be
in use in the food packaging industry. <end quote>
I will try the material used in cereal boxes, which we all know is indestructible and will last forever. So typical of our throw-away society. It is in the range of the correct thickness and should work fine. In any case it will be cheaper than the mylar I've purchased as long as I eat my Cheerios.
I should have my first prototype done within a week. I'll post results here. If successful, I plan to make small production runs of these diaphragms which I will make available to Orange County Speaker. If there is enough interest, I will follow that with new AMTs complete.
Meanwhile, if anyone reading this has ever blown a diaphragm, please post what the circumstances were, how old, and if possible, what material it was made from. I've read elsewhere how fragile they are, but in my experience they can take a serious beating without harm. 30 years later mine still crank like new. |
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| SilverFox |
I haven't checked to see if this company actually has them in stock, but they do show the proper part number of 689-1107 for the Great Heils.
http://www.speakerrepair.com/ocsdiaphragms.html
I bought my AMT1's brand new in the early 70's, and they are still my favorites today. I've never had to touch the Heils and they sound as good today as back then, but I did replace both of the woofers due to age disintegration of the surrounds (I bought new ones directly from ESS about 10 years ago when they were still in business in California).
I jump in here because I have recently picked up another pair of the Heil units that came off of a set of Rock Monitors. I'm planning on using them as the starting point for a set of homebuilt speakers, and I'm thinking of cloning the "Kithara" speakers shown here:
http://www.unitedhomeproducts.com/id101.htm
I'll be back with some questions for those of you who have built your own using the Heils. |
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| Braggi |
Note the "NLA" by the part number. No Longer Available.
They've asked me to supply them should I get into production.
Cloning the Kithara will be a fine project should you get it right.
Keep us posted.
That Syrinx looks like a beautiful thing too and more reasonably priced. Interesting angled woofer in these speakers.
I have a pair of AMTs in that flat configuration. They're not as efficient as the "Great Heils" but the sound quality is the same. I have no idea how old these AMTs are but I've not seen anything from ESS in that shape, but then, ESS made a lot of different speakers. I plan to use them in a ceiling mounted OB system with the AMT mounted on/below the bottom of the baffle. |
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| SilverFox |
I can't believe I missed the "NLA". I guess I was thinking of something else... like how I get to play online while at work sometimes. Life is good. :)
I've decided on the Kithara design for sure, and I've begun the AutoCad drawing and am filling in the blanks as I go along.
However as you suggest, I have a lot of research to do if I am going to do it right.
Since the Heil is going to be mounted at the top, it doesn't really need any design considerations having to do with the speaker box itself, but I'm having to give some serious thought to the bottom section and how it will perform with the 10" driver.
Of course, the manufacturer gives no clue about the interior design they use, probably for competitive reasons, but I doubt that it's just an open bottomed box (they do state that the bottom is open ported).
I'm toying with the idea of working out a transmittion line design for several reasons, and I'm open to ideas about that.
For me, deciding on the interior design of the bottom box is the most difficult part of the project. |
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| Braggi |
| Best of luck on that part. There are many good TL boxes out there and ESS even made a few. You should know these AMTs are very particular about the crossover network you employ. It will be a sweet speaker to bi-amp using an active adjustable crossover. If you choose to go passive you might want to buy a used ESS crossover on ebay as a starting point. |
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| Jonathan Bright |
| Hi Braggi, greetings from the underside of the world (Australia). I have just picked up some old ESS units (SP12 something). They had a 12" bass unit with a foam covered Aux bass radiator mounted at the rear of the box. I'm familar with the "Greater Heil" from mag' reviews and early promos many years ago. I guess what I have bought are the "Lesser Heils" They look similar to the units in the 'Syrinx' or 'Aulos' models that are on the "unitehomeproducts" website. If so, they look like they run from about 1k Hz and are 4 Ohms acording to the combined system spec'. From your experience can you confirm that please? and can you give me any further info' on them. Thanks Jonathan |
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| Braggi |
G'day Jonathan,
The new Syrinx and Aulos are new products from a new manufacturer and we shouldn't assume they compare to any of the old ESS models exactly, although they might be upgrades from the old ESS lines.
All of the "Great Heil" drivers and systems I'm aware of have a nominal impedance of 6 ohms. I do have a pair of those flat ones as I mentioned earlier which I'll have to investigate with my meter to give a DCR. For now assume the system is 6 ohms.
Do you know if the Heil unit in yours is open behind the diaphragm? The AMT-2 (If I have that right) is the model with the magnet assembly directly behind the diaphragm and only fires forward. Then there's the flat one which ESS used in bookshelf speakers with the sealed tube behind. Although I've heard the AMT-2s and they do have that sweet AMT sound, the dispersion is hampered severely by the design. The flat ones (need to find the name of these) can be removed from the boxes, have the tube removed, and remounted on top to give the full 360 degree dispersion the Heils are famous for. I recommend it highly.
BTW, regardless of many folks' comments to the contrary, the old ESS woofers are worthy of refoaming so don't toss them out if the surround is looking bad. Mine have the 12" pulp cone woofers and came with 14" flat passive radiators. When my passives died I had to replace them with 15" cone passives since they never made replacements for the 14s. I think the bass response is now deeper and fuller so it was a fine thing to do. If you like chest thumping low bass, you'll need to add a sub but I think that's the case with most speakers from the '70 and '80s so no surprise there.
Good luck bringing them back to spec. |
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| Braggi |
Oops, forgot to mention the crossover: AFASIK, all the greater Heils were crossed over by ESS around 1,000 hz. I've heard the AMT-2s were crossed at 2,000, but I don't know that for certain.
I'd be careful running them much lower which could smoke the diaphragms. I understand when overloaded the magic smoke that makes them work is released and that it smells real nasty.
Take care, mate. |
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| Jonathan Bright |
Hi Braggi, Thanks for the prompt reply. I've done a bit of searching since the last post. You're right, mine are clearly not the same as the "Syrinx" et al. Mine have 6 slots in the face plate and I think their's have 8. The ESS model number is PS 12-C. The bass and passive unit are both 12". The active unit looks a bit "CTS ish" and is in good condition. The Heil unit has a fairly substantial mild steel face plate that is over an 1/8" thick and measures roughly 21/2" by 4" There is a plastic cavity behind the unit that would hold about two cigarette packets or a bit more. There was also a larger plastic cover over the front of the high frequecy units that can only have "muddied" the sound while trying to improve the aesthetics. I haven't done a wiring diagram yet but there are 3 coils and 3 capacitors which look pretty fragile. It may be a third order c-over but its complicated by a pot to adjust level and a small item that may be a thermal cut out. Will explore more tomorrow.
I've run a frequency sweep through them and they are clean to 12.5kHz with nothing after that which I think means I can still hear up to 12.5k! which was a pleasant surprise.
I'm probably going to run them at a higher frequency in a three-way rather than a lower cross over. As the complete pair of boxes cost me 56 little Aussie dollars (about $46 US) I felt I've got a reasonably cheap bit of history.
On a less thechnical note I notice that your begun your reply with "G'day" and concluded with "mate". Does this mean you are familar with Australia or just watched too much of "The Crocodile Hunter"? Thanks again Jonathan |
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| Braggi |
Naw, never saw "The Crocodile Hunter." Used to watch the Paul Hogan Show when I was a kid. I haven't watched TV since 1975. Here in the US we all want to be Aussie, at least to try it out. Paul Hogan makes it look like a lot of fun. Would love to come over and spend a few weeks there.
Check these out: http://www.springsguide.com/classif...ayAd.asp?id=450
They look like nice little three ways, but I'm not sure that's better than leaving the Heils covering a wider frequency range. You'll have to let us know how your project turns out.
12.5 K? Yeah, my HF hearing drops off fast above 12 K as well. Damn. I drove a very noisy old bulldozer for a few months when I was 17 with no ear protection. Of course, it's a male trait anyway that our hearing will be less sensitive in HF as we age, but I don't think the industrial age has done men a lot of good in that department. Means we need to have young ladies come by and listen to our systems to make sure the tweeters are working correctly. :)
Good luck on your build. |
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| cdfr |
Hi,
I wanted to come back to Jonathan and Braggi's mail about the impedance of the Great Heil.
I measured the resistance of the Great Heil cartrige (I assume that it is purely resistive, not capacitive or inductive) and I find 3.5 to 3.9 Ohms (there is variance, I measured 8 great Heil cartriges).
The AMT 1 A, B, C , D, E and Monitor woofers are around 6 Ohms impedance (from litterature)
Cheers,
cdfr |
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| Jonathan Bright |
| Somewhere recently I came across a German site that has some data on the big one and almost nothing on the AMT-2. It is www.hifisound.de or something similar. www.mywebpages.comcast.net is also worth a look. The guy diyed some. |
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| matt28sr |
Hey guys:
I have been thinking about trying to make the "689-1107" diaphragms also. But I must admit I've noted some things about them that discourage my confidence in a successful outcome:
First of all, the conducting traces on all but the very early diaphragms are not single aluminum strips, but rather two side by side "serpantine" tracings that appear to be etched, or more likely printed on to the mylar/polypropelene/whatever membrane surface.
The back of the tracings appears to be coated with a black material (teflon?), or perhaps the entire tracing is some kind of conductive material that is black, though I don't know what that would be.
The circuit that these tracings form is more complicated than a simple "square wave" patern. It appears to double back on itself at least once over the entire membrane surface.
I have recently met a DIY member, here in my neck of the woods, who claims to have this circuit recreated as a CAD file. Nevertheless, I personally do not have the means to print this circuit onto a membrane...How would one go about that?
Then of corse, there is the membrane material issue, that has been addressed here, but not really resolved. But should we be able to work out all the other issues, that would leave one free to experiment with all sorts of materials....I can tell you that I was once told by an ESS tech that the all-Teflon-coated diaphragms were a disaster.
There is the problem of the mesh grid that is adhered to the top edge of the pleats on both the front and back of the mounted diaphragm. What is it? Where can we get it? With what adhesive does one attach it? (You can't see any excess adhesive around the mesh at all, and it's quite solidly attached to the membrane.)
I do know that ESS claimed this 'gri'd was necessary to keep the diaphragm operating within spec for any period of time.
Finally there is the matter of the correct surface tension to keep while mounting the diaphragm into the frame. Does anyone have any idea of what this should be, or how to measure it?
I have been told that by design, Heils do not require as strict of tolerances as other types of audio drivers (as the electric signal will force the "push-pull" pleats into alignment), but they do require some reasonable tolerances, none of which I know in the least.
Not to discourage anyone, but all this does present quite a challenge for even the most talented, educated and well equiped DIYer, any of which I certainly am not. Still, circumstances may force me to attempt it anyway. If anyone knows the answer to any of the above questions please post replies....
Meantime, something has occured to me: The void left by ESS is quite a considerable market for a third party part maker, or another speaker manufacterer. After all, the Heil AMT patent has expired, there is obviously a large demand for this part, and it shouldn't be that difficult for a technical facility to re-create it...so why not?!
All we need to do as a group, is figure out who would be the best candidates to approch for making the part. Then we all write to them 'en masse' until one of them caves!
Perhaps Parts Express, ScanSpeak/Tymphany, or Madisound would be interested. These companies are well aware of Heil AMTs. I'm sure you all can think of quite a few others.
What do you folks say? If anybody thinks this is an idea worth giving a try (or not), post a reply. In following the rules of this forum, should we decide to go ahead with this, we'll start a new thread.....
After all...we need a reliable source to get AMT digaphragms from! Do you really want to spend all your speaker-building time and effort trying to re-create this single, complicated part?! |
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| Braggi |
Matt!!!
Shhhhhhh!!!!
Nobody's looking, right?
I think there will be a new source of AMT diaphragms soon.
OK?
Patience, my friend. |
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| tomtt |
| quote: | Originally posted by Braggi
Matt!!!
Shhhhhhh!!!!
Nobody's looking, right?
I think there will be a new source of AMT diaphragms soon.
OK?
Patience, my friend. |
ESS/HEIL AIR 689-1109 RIBBON DIAPHRAGM-AMT-5
1-5/8"x2-15/16"
Air Motion Transformer
(Temporarily discontinued) $89.00
NLA
ESS/HEIL AIR 689-1107 RIBBON DIAPHRAGM-AMT-1A/1D
1-9/16"x5-9/16"
Air Motion Transformer
(Temporarily discontinued) $89.00
NLA
from here-
http://simplyspeakers.com/12diaphragms.htm
11596 |
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| c2cthomas |
tomtt:
I emailed Simply Speakers back in Jan.
"To: info@simplyspeakers.com
Subject: ESS Heil Diaphragm # 689-1107
I notice that on your web site that the ESS Heil diaphragm #689-1107 is NLA but now the listing states that this part is "Temporarily Discontinued". I'm using Heil's and am into the DIY thing and most of us are aware of the move ESS made from California to Germany and that when that move happened availability of these parts went down the tubes. Moat of us are also aware that the part "might" be available from Germany - at a greatly increased price compared to when it was available here in the States.
My question is - do you plan on selling this part again in the future (please, please, please)? If you do intend on making parts available do you have any idea when that might be and what the cost would be?
There are many of us at the diyAudio.com forum that would be very interested to find out any information about these parts - as well as the availability of the Heil AMT speakers."
The next day SS sent the following reply:
Hello,
We will let you know if and when they become available.
Regards,
Sean Ryan, Tom Ryan, and the crew at Simply Speakers
I thought it was very nice of Sean & Tom nice to answer my inquiry so quickly - and I'm keeping my fingers crossed that someone will pick up a replacement.
But the idea of DIY diaphragm and a DIY Tweeter have some merit. When I inspected the build quality of my units I found them rather lacking by todays standards. With some Neo's and DIY diaphragms some interesting things might be able to be accomplished. I know that I have some ideas in mind that I would like to try out - just for the sport of it all. ':D' |
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| tomtt |
| quote: | Originally posted by c2cthomas
I know that I have some ideas in mind that I would like to try out - just for the sport of it all. |
you gave me hope-
11615 |
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| c2cthomas |
tomtt:
Info about the Heil AMT is at http://en.wikipedia.org/wiki/Air_Motion_Transformer
Also provided is a link to view the patent about this device and some other follow on designs (Cerwin Vega, # 6111970 looks interesting).
The Heil patent shows the foil pattern used on the diaphragm ;)
Wikipedia also mentions that pizeo's are sometimes used to excite the diaphragm (hmmmm).
I wonder how Dr. Heil determined the ratio of vertical height of the pleats to the depth of the pleat. Also the overall height to width ratio of the entire diaphragm. Could the design of the diaphragm been different given the stronger magnets we have available today? Then there is the issue of magnetic field design - for which we now have software tools to model.
Also to be considered is heat dissipation - moving air that fast does generate a good amount of heat. But there is software for that too.
Any good magnetic and thermo design people out there?
Lots of things to consider - and to play with!! :bigeyes: |
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| promitheus |
this picture was posted a few posts back.
when this side is in the front does it mean the red wire is plus.
my diaphragms hace blue and purple. How do I know which is plus. |
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| Terry Demol |
| quote: | Originally posted by promitheus
this picture was posted a few posts back.
when this side is in the front does it mean the red wire is plus.
my diaphragms hace blue and purple. How do I know which is plus. |
These are the diaphragms I have and posted measurements for.
As stated elsewhere, use a 1.5v battery and tap the leads on it.
With a magnifying glass you can see the diaphragms action and
deduce which side the air is "squeezed" out of and which side it
is "sucked" in.
cheers
Terry |
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| Braggi |
Polarity doesn't matter much although it makes sense to hook both drivers up the same way in a stereo system. In fact, both sides of the diaphragm push and pull at the same time, just on opposite sides of the same pleat. Remember the diaphragm doesn't move in and out like on piston type speakers.
Polarity with regard to woofers is meaningless.
Making your own diaphragms isn't trivial, as I have discovered. OTOH, I haven't worked that hard on them. I now know the materials the latest ESS diaphagms were made from, but these are reputed to roll off in the highest frequencies in exchange for handling heat better, so I'm not investing in that material just yet. Still working with mylar which has worked well in mine for 30 years.
More soon I hope.
Meanwhile, the rest of you, try making your own and getting back to us.
-Jeff |
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| dshortt9 |
I have these and they are excellent. I believe they are bipolar, not dipolar in that when the pleats squeeze together the wave is the same phase on both front and rear. A dipole has opposite phase in the front compared to the rear.
It technically does make a difference if they are wired in phase to the woofer and depends on the crossover used. |
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| Terry Demol |
| quote: | Originally posted by Braggi
Polarity doesn't matter much although it makes sense to hook both drivers up the same way in a stereo system. In fact, both sides of the diaphragm push and pull at the same time, just on opposite sides of the same pleat. Remember the diaphragm doesn't move in and out like on piston type speakers.
Polarity with regard to woofers is meaningless.
Making your own diaphragms isn't trivial, as I have discovered. OTOH, I haven't worked that hard on them. I now know the materials the latest ESS diaphagms were made from, but these are reputed to roll off in the highest frequencies in exchange for handling heat better, so I'm not investing in that material just yet. Still working with mylar which has worked well in mine for 30 years.
More soon I hope.
Meanwhile, the rest of you, try making your own and getting back to us.
-Jeff |
Sorry, this is not true.
AMT have polarity just like any other driver.
Driver polarity is specified such that when connected correctly, a
+ electrical impulse will move the driver forward. The AMt is just the
same, on a + impulse the pleats will "squish" air forward at the front
and "suck" air inward at the rear.
The end result is exactly the same.
Also absolute phase in conjunction with other drivers is also
important, as is with any other driver.
cheers
Terry |
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| studervox |
Hi
Wat do you search the + polarity
cheers |
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| promitheus |
well I am searching for the polarity because I have a DIY set of speakers and I am not sure if the polarity is correct.
From what I know it should be in phase with the woofers I am using. |
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| theAnonymous1 |
Phase is relative; just flip a coin and hook the AMT up. Play a sine wave of a frequency near the XO point. Now listen very carefully and switch the wires. You should definitely be able to hear a difference. It should sound "louder" and more coherent when in phase. If not, then just leave it alone and consider all well.;)
BTW, where did you get those replacements? ESS doesn't sell them anymore as far as I know.:confused: |
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| theAnonymous1 |
| quote: | Originally posted by dshortt9
I have these and they are excellent. I believe they are bipolar, not dipolar in that when the pleats squeeze together the wave is the same phase on both front and rear. A dipole has opposite phase in the front compared to the rear.
It technically does make a difference if they are wired in phase to the woofer and depends on the crossover used. |
I was just playing round with my Heils and I can confirm they are dipole.
I held the Heils up to my ears like a pair of headphones. I turned one of the heils around and the signal was out of phase with the other Heil. Definitely dipole. Mystery solved.:smash: |
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| dshortt9 |
| Very good! That would confirm they are dipoles. I stand corrected. |
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| theAnonymous1 |
My goal wasn't to correct you; I just wanted to know for myself.:)
It's a very strange feeling, having out of phase signals that close to my brain. Kind of makes me.......:xeye: |
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| Jonathan Bright |
| I think that's certainly true of the first (or larger model) but I think the smaller ones I've got with the sealed back would usually be understood to be "direct radiators" with the rear energy contained. |
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| Annette&rick |
Hello matt
My name is Ricky caudillo
ESS is back in the U.S.A we are making the diaphragms to the original patent WE HAVE 1107S IN STOCK
We will have more models available soon.
Please give me a call 310-962-0114 will give you more details.
We moved every thing from Sacramento to southern California we are in the process of relocating the Germany operation back to los Angeles
Leo David the original owner wants to keep it here
So pass the word out we are back
Thank you
Ricky caudillo |
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| c2cthomas |
Hello Ricky,
Welcome back ESS!!! :hug:
I'm looking forward to at least being able to get replacement diaphragms for my AMT's.
I would be very interested in seeing a new AMT designed with todays technology and materials.
I'm wishing the best for you and your efforts!
:cheers: |
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| dshortt9 |
| The latest AMT's that I purchased from your "moving sale" are excellent as is. I get many compliments about them. Will you be selling them to DIY'ers? |
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| promitheus |
is there a reason why ess is going back to the US?
will there be new products? |
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| theAnonymous1 |
I hope they start producing a new version of the AMT.
I mean if they can make the most important part of the AMT (the diaphragm), then why not the other bits. What's left after the diaphragm; four ceramic bar magnets, two pieces of angle iron, and some stacked bits of stamped steel? That can be all that hard to reproduce.
It's not like they wouldn't sell.:D |
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| JohnL |
| quote: | Originally posted by theAnonymous1
I hope they start producing a new version of the AMT.
I mean if they can make the most important part of the AMT (the diaphragm), then why not the other bits. What's left after the diaphragm; four ceramic bar magnets, two pieces of angle iron, and some stacked bits of stamped steel? That can be all that hard to reproduce.
It's not like they wouldn't sell.:D |
Actually, they did. Right before they closed up shop, they were selling AMT pairs for $300 (I bought a pair). What I'd like to see is an updated design; some neo magnets and some FEA software used in the design to eek out the best out of an already great design. Something with the same basic parameters as the original that could be mounted in a baffle would be nice. Mundorf is doing it (and charging like they are made of gold), Eton is doing it, Beyma is doing it. Heck, there's even a DIY hobbiest in Germany that makes his own and sells them on ebay from time to time. You'd think the originators could knock out their own updated design. |
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| chrisb |
Ricky - the abundance of new &/or improved derivations of the AMT design, some of which are commanding outrageous (except to the makers) prices, would suggest a growing interest for this type of product, particularly for the DIYer looking to pursue alternatives to domes, or ribbons.
In addition to replacement diaphragms for existing pieces, if ESS has considered updating the design with new magnetic materials and assembly techniques, hopefully they won't engineer our the features that imbued the original with its magic
I've had the opportunity to play with a pair of one of the models of "pleated ribbon" drivers used in Mark & Daniels.
This particular model is much smaller than the original AMT1, particularly in regards to the motor's magnet assembly, and the diaphragm itself is somewhat shorter. Aside from the substantially lower sensitivity, the M&Ds are not quite as dynamic or transparent at the originals. |
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| theAnonymous1 |
| quote: | Originally posted by JohnL
Something with the same basic parameters as the original that could be mounted in a baffle would be nice. |
I'm having some aluminum panels made to transform(disfigure?) my AMTs for open baffle use.
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| Annette&rick |
thank you everyone for the support and feedback.
as i said in my first post we will have some new product in the future .
after reading all the posts it seems the diaphrams were most important. we read all of oscars original notes again and we will remain 100% dedicated to the ess quality. we have 1107 1108 1109 diaphrams in stock and we have some ess speakers with the hiel tweeter, will give update early next week .
thank you
ricky
ESS |
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| c2cthomas |
Hi Ricky,
Thanks for posting the feedback. I lived in Sacramento and worked at Sun Stereo fixing broken amps and got to know a couple of the techs over at the ESS plant in Rancho - so my memories of your company goes back quite far.
I'm looking forward to your new efforts - and hope that you can get a web site up soon so we can order parts (and maybe some NEW stuff).
I personally want an AMT that is about the size of my front door so I can sit in front of it and use it for a fan while I'm listening!!! :yikes:
:cheers: |
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| Annette&rick |
for all you DIYers you can order NOW please give me a call
310-962-0114 or EMAIL your order to ricky@starvision.us
WE WILL HAVE A MY-SPACE VERY SOON
thank you in advance
RICKY
ESS |
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| nyatt |
HI. What material will be used for the diaphragm, as it seems at least 2 different materials were used (kapton and polyethylene and maybe teflon?).
Thanks! |
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| Annette&rick |
hello
as for the material we will go back to the original mylar as per
oskar hiel patint the circut is a double sided we have made all new tooling to the original specs.
thank you
ricky
ess |
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| c2cthomas |
Hi ESS AMT users.
I need to tip my hat to the crew at Simply Speakers! I contacted them several months ago about the availability of replacement diaphragms for my AMT's and they said they would contact me when they became available. Well that was several months ago - BUT - someone at SS is VERY good at keeping track of their customers needs and took the time to contact me today with this:
Hello,
Please see the “speaker diaphragms” page on our website. The 689-1107 are $89 each and in stock.
Please give us a call or e-mail if you need more information.
We will be happy to help you.
Regards,
Sean Ryan and the crew at Simply Speakers
Visit our website! http://www.simplyspeakers.com/
That's some great news - a great price - and some really great service (and no - I am in no way affiliated with SS other than buying some parts from them).
http://www.simplyspeakers.com/12diaphragms.htm
:cheers: |
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| Keith Taylor |
I have owned a pair of Heil "Elite" tweeters since the 1970's and reluctantly retired them when I tried to get to the bottom of what was causing one of the diapragms to rattle at considerably lower levels than the good one. It was when I was in the process of adding some car body filler to the magnet assembly to fill in a gap where a plastic magnet cover abuts the pole pieces that I saw the problem. More about this later. These Heils, which are probably the same as those in the AMT1 have been notable for a couple of high frequency peaks in their amplitude/freq response. These peaks are more noticeable off axis and occur at around 5.5KHz and 11KHz. The distance between the diaphragm and the discontinuity in the magnet happens to be a quarter wavelength at 5 odd KHz so we have a diffraction problem. Levelling out this groove gets rid of the peaks.
When peering at the diaphragm with the aid of a torch (flashlight) I could see some foreign material adhering to one of the pleats. The material was actually a thin sliver of diaphagm offcut that was either coated with an adhesive or had been bonded to it with a coating process. Gripping it with a pair of tweezers it eventually came away but unfortunately it tore the pleat. Needless to say I was glad to see that diaphragms are now available again.
On the subject of home made Heils Neil Davis described 5 different magnet structures and three diaphragm sizes in The Audio Amateur issue 2 1977. Kenneth Rauen's horn loaded Heil parts 1 and 2 appeared in Speaker Builder issues 3/82 and 4/82 Both builders settled on the same method of diaphragm construction. The aluminium foil conductor was cut out with a knife and bonded to a thin sheet of polyethylene film with rubber cement. A second sheet was then bonded to the first so that the foil was sandwitched between the two. Neil Davis seems to have had an ongoing interest in Heils and posted a few progress reports on a mini Heil on the Madisound forum some years ago.
The mid range and tweeter drivers used in the ADAM (German) monitors are the subject of AES preprint 4984 The diaphragm material is Kapton and author Heinz remarks that the mid range diaphragm had to be coated to "avoid foil resonances" An aspect that caught my eye was the impedance curves which would have to be the most benign of any speaker yet devised. This demonstrates that Heils have a much better impedance match to the air than cones and domes etc. Someone in an early post mentioned piezoelectric Heils. AES convention paper 6579 is titled "Wideband piezoelectric rectangular loudspeaker using a tuck shape PVDF bimorph" I found this paper to be a mine of non-information on how the thing works, but rather concentrated on its acoustic properties. It looks like it owes much to the Heil principal, but there are no references to Heil whatever. The PVDF is a polymer film that has been folded into a zig zag shape. One can only speculate that when apropriate voltages are applied to the pleats the creases either close up or open up thus emulating the Heil diaphragm. The frequency response plots are none too impressive.
An idea that occured to me some time ago was an electrostatic realization of the Heil principal. By getting rid of the magnet we remove a major impediment to the acoustic design of the transducer. There is also no limit to how wide the diaphragm can be made or how deep the pleats can be. By having access to individual pleats there occurs the possibility of controlling directivity by altering the acoustic size of the source. It could be an answer to the problems of wavefield synthesis where the array of separate speakers leads to spatial aliasing. The hard part is having to deal with the needs of ESL's namely having to wrap the membrane around something to give it a defined spacing between pleats and worst of all to have to apply tension to the pleats and put up with the inevitable drum skin type resonances. Hope you found something of interest.
Keith |
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| abzug |
| Thanks for all the links, once I have 5 Usd on my acc (tomorrow ) I buy the Adam midrange paper and share it , hopefully something hits the market along the same line ( 96dB sensitivity AMT mids ) |
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| MeanGene |
I have four of the ESS AMT3 Rock Monitors and want to create a 5th center channel version. I need a complete Heil AMT for the project. Anyone know where I can get one?
Here is some additional info that may help with connecting up drivers in ESS speakers.
Usually, but not always:
Negitive wires are colored - Black, Purple, Brown, Red
Positives wires are colored - Green, Yellow, Blue
This information was provided by an engineer at ESS when they were in Sacramento.
By the way, here is the latest ESS that I have seen.
MeanGene |
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| roadiemanchild |
Great to hear that I can get replacement diaphrams for my AMT's again!! What ever happened to the Blue Ox platform?
Paul |
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| rvcarrillo |
Hello,
Iwas wondering if anyone knows anything about ESS and it's reopening.
Thanks. |
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| Gregster |
Hi Ricky,
Got new ribbons for my ESS Heils today and hooked them. They sound fantastic just like when I bought them new back in 1973 in Chicago. You went out of your way covering my lifetime warranty and I wish you much success in your business bringing back one of the best speaker systems ever built.
If you need anyone for a good testimony in the future for your upstanding business practice and standing behind your product, please let me know. You can use this email if you would like to tell others what your all about. You are unbelievable. Thanks again.
Sincerely
Greg Lovick
Fortuna, California |
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| promitheus |
I have a question.
How do you know which is front and which is back?
Greetings |
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