Air Motion Transformers (Heil's) and New Diaphragms

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I was wondering if anybody had data about the 6.5 inch AMT3 speaker and the two 10 inchers?
I looking for this info to see what can be used to make a modern incarnation of AMT 3. I ha AMT 1 E Monitors and that configuration forces the Heil to take over at 1Khz which is no great. Better would be to cut at 1.5khz.

OCS Recommend the Emminece 1040SF for the woofers, and the Emminece Alpha 6 for the transition driver, be aware this is not a mid range in the traditional sense, its a midwoofer.
I have two pairs of these, the 1040SF is the way to go, my had the orginal transition drivers, so there was no need to upgrade, if you have the orginals, leave them, as they work excellent,
The 1040SF are efficient, and give you a db our two more output over the original woofers, and useful output down to the low 30hz,s, and will rock your house!!.
Use the 8 ohm version of the AMT3 crossover, it works well, and leave the trasition driver, as ESS had it out of phase with the woofers, it works better.
I have tons of information posted on Audiokarma on these.
 
AMT-3 Crossovers

Attached is the ESS official crossover diagram and the diagram of the crossover I made w/ values I found on one of my existing crossovers.
 

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I have 2 sets of AMT3's. One 4 coil pair, and one 3 coil pair. The 4 coil pair has the Peerless rubber surround transition driver (mid).
The 3 coil crossover was used in later models, and those models had 8ohm
woofers.
The 4 coil was a earlier design, and used 4 ohm woofers. Those extra resistors as far as I can tell in effect made the 4 ohm woofers 'appear' to be 8 ohms.
To me, unless you are using the stock 4 ohm woofers, is needlessly complicated, and I would suggest going with the 3 coil design, particuliarly if you are using other 8 ohm ESS woofers as replacments, or 1040SF woofers.
I decided to replace my 4 coil crossover with a totally new set of crossover patterend after the 3 coil design.
I also went with the 1040SF's in both pairs, as it seemed more cost effective. It preserves the over all voicing of the speaker, but gives you better low end response as well as extension.
The Dayton Classic 10" is another replacement possibility, but I would recommend saving up for the 140SF's if cost is a concern, well woth the extra$ IMHO-awesome woofer!!
 
The various AMTs are quite different IMO, not only in the material, but also the magnet and structure. Oskar's do not use a metal nor mylar. Wonder what is. The history of ESS changing the membrane material and the results commented by people here are significant to show how a delicate mix such a transducer is.

I recently found this to be the case. In point, i have been listening to my 1B pair of old heils (and we're talking original AMT units here) for some 17yrs without noticeable degradation when i decided to pull the amt's and put in new diaphragms. Something's amiss. The old diaphragms are 30something years old and they sound significantly brighter than the new ones. Threw both pairs on my dmm and they're all within .4ohms of each other but i removed the new ones again and left the old in place as they're the keeper in my mind. Who wants a pair of new diaphragms for cheap as they're for up for grabs now. They work, but the untrained ear is the new owner of these ESS bummers.

I'm losing faith now in their new stuff altogether.
 
FYI: I have not gone through all pages of this thread - sorry if this is a repost.


http://www.parts-express.com/wizard...main&WebPage_ID=3&searchFilter=Heil&x=25&y=11
264-600
264-600 ESS Great Heil Air-Motion Transformer (2 reviews)

Unlike a normal piston loudspeaker that excites the air by alternately pushing and pulling a cone or dome, the AMT linearly squeezes and expands its diaphragm's pleats, moving the airload at a very high velocity.
List: $399.00
Now: $350.00

264-606
264-606 ESS Heil 1109 PS-5 and PS-6 Replacement Diaphragm
Mfg. #1109: fits PS5, PS6D, PS8A, PS810, PS910, PS1010, PS1210, PS820, PS920, PS1020, PS1220, and many more.
List: $79.95
Now: $70.00

264-604
264-604 ESS Heil 1108 CE-1 CE-2 AMT-4 / AMT-6 Replacement Diaphragm
Mfg. #1108: fits CE1, CE2, AMT4, AMT6, PS8H, and many more.
List: $89.95
Now: $80.00

Items 1 through 8 of 8. All Records Show
 
I recently found this to be the case. In point, i have been listening to my 1B pair of old heils (and we're talking original AMT units here) for some 17yrs without noticeable degradation when i decided to pull the amt's and put in new diaphragms. Something's amiss. The old diaphragms are 30something years old and they sound significantly brighter than the new ones. Threw both pairs on my dmm and they're all within .4ohms of each other but i removed the new ones again and left the old in place as they're the keeper in my mind. Who wants a pair of new diaphragms for cheap as they're for up for grabs now. They work, but the untrained ear is the new owner of these ESS bummers.

I'm losing faith now in their new stuff altogether.

Ok, but take a look on audiokarma for example and you will find other that have a complete opposite experience.
Perhaps Rick @ESS could shed some light. I think if I was buying new diaphrams I would buy them direct from ESS-then if you have a problem-you have some recourse.
Perhaps these need time to break in. I haven't had a lick of problem with my great Heils- but my old PS1220's in the 80's would ocassionaly melt a diaphram-rooms mates and clipping amps.
The Great Heils are pretty tough, keep the fuse in place and you will be listening them for years-I can't tell the difference with the fuse in or not-so I keep it in place-better safe than sorry.
 
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Who wants a pair of new diaphragms for cheap as they're for up for grabs now. They work, but the untrained ear is the new owner of these ESS bummers.

How cheap? (you can PM me a price if you wish)

My original diaphrams work fine, but are in pretty rough physical shape. One even has a small hole in it. Do you think they are worth keeping?
 

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I fried one of the original 1c diaphragms while making a new 2-way. I had no choice but to get a new, current production matched pair. The sonic measurements were virtually the same between the two but the new diaphragm material, mylar I presume sounded a bit colder, more extended and strident. After a couple weeks of break in either my hearing may have adapted or memory faded as they sounded very close to the originals albeit slightly tighter, more detailed at the cost of a bit of sweetness. Frankly, I like it this way. And they do seem to get better with age. Just my experience.
I use Altec 414c's as well in a transmission line configuration- without the passive woofer of course. The Altec's integrate well; fast, transparent, excellent transient response and timbre. By no means perfect but the experience convinces me the Heil's need the fastest most efficient pro-drivers to balance their sound. Audax PR17OMO might be another good choice if shooting for a MTM or three way with a JBL bottom. Me, I am still happy with the tight and flat 40hz I am getting out of mine. Next is to try a true isobaric dipole with dual altecs and see if I like that. I had the foresight to design the rear of my cabinet for that purpose but only tried that configuration briefly with my current 6,7 ohm Altecs (giving me about 3.3 ohms parallel). No dice as I was using the 1c crossover designed for an 8 ohm mid-woofer! A short in my cables had previously fried my Heils together with a good Marantz. That experience shied me away from trying this with an active cross again so I left well enough alone and upgraded the caps in the existing (AMT1c) crossover. Remember, the AMT1 series had a 4 ohm Heil coupled with an 8 ohm mid-woofer. Audio nirvana? No. But still better than any dome tweeter I have heard and the Altec's do their job as well. Overall I would still keep them over any other pair of speakers I have had in my living room, including a pair of Martin Logan's as they have the punch for rock, enough detail and soundstage for classical, while still maintaining enough immediacy for jazz. For me this combination of dynamics with transparency is tough to beat. Maybe the Carver Amazing's were a little more convincing top to bottom but the power, size and placement requirements put me on a different path. Just my 2 cents- as I hope this thread never ends.....
 
I recently found this to be the case. In point, i have been listening to my 1B pair of old heils (and we're talking original AMT units here) for some 17yrs without noticeable degradation when i decided to pull the amt's and put in new diaphragms. Something's amiss. The old diaphragms are 30something years old and they sound significantly brighter than the new ones. Threw both pairs on my dmm and they're all within .4ohms of each other but i removed the new ones again and left the old in place as they're the keeper in my mind. Who wants a pair of new diaphragms for cheap as they're for up for grabs now. They work, but the untrained ear is the new owner of these ESS bummers.

I'm losing faith now in their new stuff altogether.

I guess the thing I don't understand is that earlier (perhaps when you were still employed by ESS) these diaphrams were great-no problems and now-not so I great.
Am I sensing some sort of agenda here?
I have to wonder.......
 
I guess the thing I don't understand is that earlier (perhaps when you were still employed by ESS) these diaphrams were great-no problems and now-not so I great.
Am I sensing some sort of agenda here?
I have to wonder.......

You would have to point to me where i stated the diaphragms were great earlier and in any post anywhere i may have implied being employed by ESS at any time.

Simply put again, the plates were reconfigured and the diaphragms were copied. It was not until test results were procured in an anechoic chamber that the new diaphragms fell measurably short and until this time i was unaware of any differences. Having come to these same conclusions both in the facility and my own sound environment (again, after test measurements) i will go on to say this; the 146 plate-build of your amt 3 is in my opinion still the superior build. Does that confuse you more? :D Sorry automojo my post(s) reflect my opinion(s) and those are subject to change. I liken the amt1/amt3 in the towers and the amt1a/b in the pyramids to be the pinnacle of the amt successors just like you do and finding product support for any of those is absent apparently. I no longer own the new amt's nor any of the new diaphragm(s) so all of my listening is to bias towards that which i find superior, until further notice of course. :Popworm: You will find my displeasure with what ess is doing at current to wit i am again biased as my constituents sidle my opinion(s) and mirror my sentiments. I also tend to base my ongoing findings on what works and what works well so since the end consumer pleads for more information based on my opinion(s) i give it to them rather furtively. Not the case on the public forums so take it fwiw that i am more candid here and more so with any other. Some details i won't release in print however but again it's a constituency factor and nothing personal mind you. These are less biased than anything else you might find in my post(s) but they are in fact embarking on trade infringement and my conscious won't allow me to go there in public. My opinions differ rarely from my findings both professional and personal. Anything else i can help with i will try. I am back out of state for another week and a half so i will see you around mojo!
 
Hey all,

New to the forum, I was sent over here by the good boys over at AVS. I recently came across as set of ESS HEIL Tweeter as well as the crossovers from a pair of ESS AMT's. So first off the crossover is as confusing as hell but hopefully I can figure it out. Maybe some of you could give me a hand with that. Now I am looking to rebuild these bad boys. Starting off with woofers, what would pair up well with these Heils?

I am BRAND new to the DIY scene but am great with electronics and have a wood working shop and carpenter at my disposal, so although it may take me longer than the normal person, I should be able to accomplish the task.

I've also just thought of contacting ESS and seeing if I can buy some boxes off them depending on the price. So back to the woofers, any suggestions??

Thanks.
 
ESS AMT-3s

Hello All, I'm the original owner of a pair of ESS amt-3's from late 1970 or early 1971. WOW that"s 40 + YEARS & YES I'm an old bird!!! I'm looking for some current general info about these speakers. Value etc. I have had all the speakers rebuilt with Original parts as directed from ESS. I do use my amt-3's daily and really enjoy the clarity of sound reproducion. I still have a turntable and about 300 vinyl albums that sound great thru my amt-3's. I power the system with an ADCOM amplifier
which gives me lots of power. Oh! by the way I do still have the original
literature and warranty registration cards, No. 97440 & 97442, from when ESS was in Sacramento Ca. Any information is greatly appreciated...
Thanks in Advance, Tom
PS: I will be on the lookout for the current email address for ESS in Europe
 
It's time to lift this thread up...

Hello, I'm using the ESS AMT 1C since ~10 Years and they sound great.
But I know about the Problems that this Speakers have with the midrange.
In Germany there are some companys like "Klangmeister" that exchange the xo with a new one without pots and set the AMT a little bit away from the front.
But they take ~700,- Euro / ~900,- USD for this modification, I think thats pretty much for some coils, foils, resistors and two new holes in the housing. ;-)

Does anybody here have succesfully built a new xo with a higher xo-point than 800Hz and could show the plans here?

Some weeks ago I was happy to get a cheap pair of AMT 1C Tweeters.
I think I will build some speakers with them, I saw some interesting projects with 8" or 10" Broadband drivers with ~97dB/w/m, like the Celestion Truvox 1020.

I use my AMT's with Transistor-Amps and with Tube-Amps, and they sound good on both Amps.


Marc
 
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I hope this Heil thread lives forever as I just bought an old pair of Heil AMTs to run on top of the Hornshoppe horns. Will use a series crossover to the Fostex. I might go active at some point to try 4th order around 1.5k. I first heard the Heil around 1978 and I will never forget the experience to this day. It was in a small college dorm room playing Aerosmith "Sweet Emotion" of all things. From about 2K up, there is nothing better IMO.
 
Old thread. I come, not to boast, but more to ask for help. I have the golden egg! I married Oskar Heil's granddaughter and now have most of his stuff, including boxes of unassembled AMT membranes and the plastic housings that they sit in. Sadly, I know nothing about engineering audio equipment (although I have done some tinkering with Oskar's ESS Bass Cube and his Connoisseur BD1 turntables). I guess it's possible that I learn to assemble these membranes and eventually can get them to other AMT enthusiasts (probably for a heck of a lot less than ESS, or the guys on Ebay sells them fo r). Enlighten me and I may be of some service. As for now, I'll just sit in Oskar's basement looking at all the loot collecting dust, because I have no clue as to how to make it work. Cheers all.
 
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