How do upload a Picture? I have pictures of the Tower and feel one should be posted so people know what the AMT 1 Towers look like. They are NOT the ESS AMT-1s

Hard to track down a compatible replacement 10" Driver

Sounds as clear as light. Fast, dynamic, coherent, life like, accurate timbre, ultra low distortion, never sounds harsh at any volume. Better than horns because they have the dynamic impact of horns, but, unlike horns, they never sound compressed or strident. Better impact than ribbons or electrostatic speakers. They present an easy to drive resistive load.

They are so lightning fast that the woofer has to be state of the art to keep up. High current amplification with a fast slew rate is a must.

The ESS Heil AMT1 Tower is one of the first-generation products of ESS, and yet ironically one of the very top performing products that they ever produced. The Heil speaker platform was/is based on the ground-breaking Air Motion Transformer which is a special compressed ribbon midrange/tweeter design that applies compression to the air perpendicular to the radiated direction of the sound. This special approach creates angular velocity which results in exceptionally high-efficiency control over the air mass with what would otherwise be considered subtle fluctuations in the ribbon. Performance Criteria (Efficiency, clarity, accuracy, lowest distortion): I haven't seen any speakers made by anyone anywhere that will even approach the AMTs for less than about 50k, and then as you throw higher and higher dollar amounts at competing products, the comparisons IMHO are a toss-up as those dollar amounts approach infinity. Heil had created the AMT1 which coupled the Air Motion Transformers with a 10" woofer in a sealed enclosure of roughly 2 cubic feet or so. The bass performance was so so, and hardly a worthy combination for the AMTs. Someone at ESS then decided to release a special luxury version of the AMT1 which took the same woofer and now engineered a transmission line enclosure that is tuned specifically for this woofer's free air resonance. Per a telephone conversation that I had with Rico Caudillo of ESS labs, the free air resonance Q point of this little 10" woofer is 32hz. The tuned transmission line creates a suppression at this FS point, and then creates two smaller Q points 1 octave above FS and 1 octave below FS, and tends to smooth out the response spectra between the three octives (64hz, 32hz and 16hz). Below the lower Q point, the response drops off very quickly. In any case, these speakers have an extremely low frequency response for their size that will make you very quickly forget that you are listening to a pair of 10" drivers. I have seen figures online that put the low end of the frequency response for these cabinets at the 38 to 40hz range, but I know for fact that those figures are not correct. I own a pair and I am able to get lows out of these that I can't get out of most speakers - lows that confirm the transmission line FS/2 octave theory. I know I can get 20hz and below. These speakers will reproduce pipe organ recordings with the 16hz 32foot bass pipes that most speakers will simply miss.

These aren't EXTREMELY loud speakers. They are exquisite at soft to moderate volumes. However at frequencies below the cut-off range, the woofers will tend to move in and out beyond their intended excursion limits. Sure you can play these speakers at loud volumes and those AMTs are VERY bright when you call on them for highs, but then you have to watch where you set your bass so that you don't drive the woofers into failure if you do so with the Loudness setting engaged on your amplifier because Loudness will tend to permit frequencies to pass that fall into the infrasonic range (i.e. everything below 20hz). That is the one thing about these speakers that are touchy. The other thing I wish they had done is created the cabinets out of plywood in stead of fiber board. If you ever wish to restore a pair of these (which I did with mine), one of the first things you should do after removing everything from the cabinet, is to treat the cabinets from the inside with MinWax Wood Hardener. If you'll do that, these transmission line cabinets will give you a VERY long life. If not, the cabinets will eventually deteriorate with age, just like any other fiber board product.

AMT 1's are impressive to look at, and have great non-audiophile sound characteristics. Heil accordion has the airy sound it looks like it would. Unmatched for breathy vocals well recorded (waay better than Quad ESL and Magnepan SMG IMHO). Ported bass has excellent presence. So sweet and satisfying. I use these for video and digital repro, since I have more serious stuff for vinyl/analog. The key to liking them was to match them with a pair of Brit bookshelves, Wharfedale DIamonds, an accident that worked out well. 1/(1/6+1/6) = 3 Ohms, but the Onkyo doesn't complain and is rated at 200wpc into 4 Ohms. I wouldn't use a digital amp, but the source material is digital, so ... Mine came with the 10" car bass driver upgrade which is just fine. About $500 years ago. I suppose I should try it again as an audiophile set-up with the coloration support in the midrange from the conventional cone speakers. But I'm pretty picky about imaging and phase coherence, so that would seem to require putting the midranges on the baffle, which would upset the appearance. Heils also seem to have an optimal volume level that is well short of what the bass set-up is capable of. For reference, ha ha, my analog set up transduces thru modified Infinity RSIIs with electrostatic and carbon fiber upgrades, and I am also turning some KEF 105/4s into 107s. The kind of sound the AMT ESS Heils produce, I might try sticking some horn drivers on them somewhere someday.

My ESS experiences began without ESS. I began selling audio components in 1956 just as stereo LP's became available. I was 22. Two rears later I opened and managed for the two owners, Stereo Sound Studio in Des Moines, the leading shop in Iowa. They gave me the ball and let me run with it..About eight years later a quarter block fire.took it away. The owners were at how to continue odds. With no similar opportunities my wife convinced me to relocate to Ft. Myers, her parents home where I found work with a TV and appliance dealer. Went on to manage several stores, the largest with it's own stereo department. It was not doing very well. I agreed to.take it over as long as I was free to run with the ball.

One of the speaker lines was ESS, from the PS-8 up to the AMT-1? which I loved and wanted but could not afford then. I used the PS-8 blindfold test story and listening test when it fit their budget. My competition at the time was pushing Bose 901 at $950 I think. I ran a
promotion using the blindfold test to offer PS-8's, Sanyo direct drive turntable with high end cartridge into Sanyo Plus 35 receiver...all for the price of a pair of Bose 901's!

Nearly 20 years later I called ESS to find a close dealer. told there were none they offered to sell me a pair of AMT-1D's discounted to $970 I sad yes but was told there were none in stock and it would be several weeks before the next production run. After crying the blues about having been a dealer and waiting 'till retirement to own a pair, the lady said to hold for a few, came back and told me they'l make a pair for me. For delivery I arranged for air freight. Problem was several airlines would not take them for fear magnet weights might effect plain's instruments. One agreed and I had them in two days. No changing trucks no loading docks, no weather damage, all for only $79.00!
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A vintage Sanyo Plus 75 with features to die for today drives them for jazz, classical including pipe organ recordings. Very little pop or rock. I replaced one woofer and have another if needed.

So, my ESS experience began a while ago so what year should I say?. I can't imagine trying to improve the sound. Thanks for reading.

Does anyone need to replace their ESS AMT-1 pyramid grills?

After re-foaming my woofers, redoing the crossovers, and cleaning up the cabinets, I decided to fabricate some new grill caps because my original grills were old, faded, and broken in several places. They were the only item I was unable to find in my effort to restore these speakers.

After struggling for a while to replicate the original wood pyramid frames to the original ESS tapered dimensions, I discovered just how easy it was to assemble the new grill frames while keeping the grill fabric flat and tight all the way around. They actually appear identical to the originals except for the fabric I chose.
I also swapped out the fabric covered tops with a black reflective glass inlay. Looks really good.

There are lots of great speakers out there but these, to me, are special. It’s the clarity and presence. Yes, I overcame the bass issues and I completely upgraded the original crossovers. They still cross at 600 Hz but the original coils, caps, resisters, and internal wiring were not even closely commensurate with the quality and ability of the Heil transformer.

Since the early seventies, I have yet to hear a speaker I would rather own.

I have been an audiophile since building speaker and Dynaco kits in college. At 29 I contracted cancer and after surviving that, I decided I was going to get a great sound system while I could enjoy it!!! I ended up finding the Heil AMT-1 Towers and am still thankfully enjoying them after 38 years. Replaced the woofers once and now doing it again with the Orange County Speaker recommended upgrade. Tops still original. I have enjoyed reading all the enthusiastic comments about these beautiful speakers, with which I concur completely. If I had to find a weakness I'd say it was somewhat of a midrange hole, especially for horns, but then I am a professional trumpet player and am used to hearing that range a lot. I reduced this problem by buying a large power receiver (Kenwood 9600) which has a midrange boost in addition to treble and bass. This really helped to warm up the midrange and I keep it set than way nearly all the time. The receiver is 30 years old itself!! And of course the highs and the presence are unequalled. (I would love to hear these speakers some time with some high powered/low distortion tube amps).

I am wondering if anyone has figured out a way to incorporate one of the new midrange drivers into this system. I see people adding sub-woofers, but nothing about midrange? Also am interested in the attempts to put foam blocks along side the ess units to help the wrap around error. Sounds simple and interesting. It was in one of the blogs on ESS. This is FUN!!

Bought mine new in Cambridge MA, Harvard Square ($595) around the early 70's. Thought I'd go for a pair of McIntosh but there was something in the air about the mids and tweets on those wierd looking Heils. I especially like the xeroxed owners manual!

As the add said - sound as clear as light. When I got them home and pumped them with my 'big' Sony STR 6060F (20 - 60,000 KHz) I just smiled and thought what a great pair of transducers for my ears these guys made. So, I called Heil and asked some questions about the AMT - seems it was covered by some 18 patents (could have been 28 memory fades after all these years) and was perfected for the motion picture theater industry.

After storing them for a few years until my kid could take them over and luckily picking up a Marantz 4300, it was time to bring them out of moth balls and stand them up like two big cat scratch posts. They looked pretty sick, covers in shreds and surrounds gone. But even at their height of glory and in all honesty, the bass did lack some for the music of the 60's and 70's. For classical music you might not miss the definition at say 20 Hz. And if it was behind a theater screen on-stage that might have made a big difference too. Afew nights in the basement, recovering them and replacing the woofers with 12" Pyle drivers they were ready for a test.

Louder is not necessarily better was the lesson I learned there. Seems the basic theory of driving the bass into the floor only shook the place but didn't excite the air in my ear canal. Sorry Heil but I can only give you a high 4 not a high five on my set. But that was 15 years ago and speaker technology has advanced so...Has anyone conquered this phenom with these speakers besides using a bi-amp and some isobarics or roof mounting them? Let me know at richcarp@richieprints.com. Thanks. Must be some of the designers left around here someplace mumble, mumble...ah, yep...somewhere. Now which wire is the positive lead...I always get that messed-up.

Hi All, I bought a new pair of ESS AMT-1A floor standing tower speakers in 1974 for $1300 + tax.. After auditioning many high-end speakers, I chose the ESS over everything else, even at twice the money! The blind fold test really did it for me, it was astonishing! 35 years old and still going strong, I've become spoiled listening to them. I recently acquired some Infinity reference monitors with the Emit tweeter { a direct copy of the heil technology } and they sound very good, but not quite as good as my babies. About 3 weeks ago I decided to test the market and put them up for sale on CAM {Canuck Audio Mart} for $800. Upon reading all 81 reviews from fellow audiologists, and with no solid offers, I've decide to keep them. I would have sold them, so to all who looked at them and didn't offer: TOO BAD! Bruce @ Eartheye Electronics

Beautiful elegant hardwood cabinets. Flawless craftmanship. Immpecable sound reproduction beyond the range of the human ear, in both highs and lows. Smooth transitional bandwidth with crystal clear highs, smooth midrange, earth-shaking bass. High power amp cabability (400 watt max per speaker). Factory bi-amp speaker inputs, along with normal full-range speaker inputs. Simply the best sounding loudspeaker ever produced. If you already own a pair, you won't ever sell them (at any price). If you ever audition them, you'll want to buy them (at any price). Best advice-- find a friend who owns a pair of ESS Amt Monitors and become his "best friend".

Big and Bulky (if you call that a weakness). Extremely heavy. 2-man lift required to move. Do not attempt to move speakers alone by yourself without risk of personal injury and/or hernia. Prior planning required before actual placement; not the type of speaker to be moved on a whem. Once speakers have been set in their permanent locations; do not plan to move speakers again, unless the house is on fire! Extremely rare to find for sale at any price-- people who already have them, won't sell them. Lastly, do not let kitty cats near the speaker grills, as they would love to sharpen their claws on them. Ownership of ESS Amt Monitors is the main reason I have never owned a cat.

While stationed in Germany in 1980, I purchased a pair of ESS Amt Monitor speakers. I still own them to this day. While at a U.S. Army HiFi store in Manhiem, Germany (1980) looking at cassette decks, I had heard different speakers being selected from customers in the adjacent "High-End Speaker" listening room. All of a sudden, I heard the most crystal clear musical sound emitting from the speaker room. I immediately ran into the speaker room and asked the attendant which speakers were being played. He said they were the ESS Amt 1b (Pyramid Style). I asked him if they were the flagship, top-of-the-line of that particular brand (ESS). He said no, the ESS Amt Monitor was the flagship model. I then asked him to play the ESS Amt Monitor for comparison. They were simply breathtaking in clarity, unparalled highs and earthshaking bass. The only other brand speaker that could even come close to comparison was the Klipsch "LaScala"; but it emitted an annoying wood-knocking thump sound during heavy bass. Needless to say, I bought a pair of the ESS Amt Monitors on the spot. At the same time, I purchased the famous Pioneer SX-1980 receiver (270 watts x 2) and it still powers the ESS Amt Monitors in a bi-amp set-up in my home theater today. Since my purchase in 1980, I have listened to countless other brand speakers. The only current-day speakers that can even compare to the ESS Amt Monitor is the flagship model produced by Martin-Logan (Summit model), with the additional support from an out-board powered subwoofer. Given a blind-fold test, 100% agree the ESS Amt Monitor is simply the best speaker they have ever heard, period. No other speaker has ever been produced that replicates the actual sound of the musical instruments and vocals as the ESS Amt Monitor. It is simply the Mount Everest among esoteric loudspeakers. As the original advertisement said-- "Sound As Clear As Light!" If my house ever catches on fire; after everybody gets out, my next priority will be to save my pair of ESS Amt Monitors-- they are that incredible! E-mail any questions/comments to: bdgreer1@msn.com

Customer Service

At time of original purchase (1980), speakers were delivered on time as promised. Repair service is unknown, as the ESS Amt Monitors have never failed, so repair service has never been required or pursued.

Similar Products Used:

The ESS Amt Monitors have been compared in personal listening tests to Klipschorn "Corner" Speakers, Klipsch "LaScala", and flagship Martin-Logan "Summit" electrostatic speakers. Listening tests were conducted with the use of blind-folds; or listener had his back towards speakers, so only the actual speaker sound could be judged (with no visual impression). Competing speakers had difficulty without the support of an out-board powered subwoofer.