I own a pair of AMT-1B's from 1977 with replacement woofers and passive radiators from ESS. In about 2000 I bought a pair of AMT 1-D's. Excepting for being all black these were indistinguishable from my original pair (OK, grill cage was all black not brown/black weave). For some reason I slightly prefer the older ones. They're a bit crisper in the high treble which is exactly the magic no cone or dome speaker could match in 1977. I've heard a lot of negatives about the AMT-1's. The first incarnation, according to Julian Hirsch of Stereo Review could experience a Heil driver blow-out by an overzealous user. The second, the B-version, was reviewed by Hirsch with vastly different results as he said they limit of what the whole system could absorb seemed to be dependent on any amplifiers "clean" (i.e. unclipped) power. No blow-outs. The sound was fairly faultless according the that 1977 review. I've found that sound to my liking. The mids are pretty revealing I'm guessing because of the low crossover point combined with the stellar large Heil di-polar transducer. You can peer into the space as there definitely is a space created which will be more or less determined by the placement and the room. I think the great thing about such a revealing mid to high transducer is that the Heil is not screechy. It's a smooth operator. It rolls off around the higher frequencies in a most natural and musical way never accentuating that range yet still putting a fair bit of it out there. I do admit the bass for a 12" woofer coupled to a passive radiator isn't as state of the art. It isn't, at least to me, that it fails musically. I do not find it slow as some have said. I do admit it's lacking in the lower registers...this is a good omission as cheap really amazing subwoofers are ubiquitous and probably sold at Walgreens. In other words for the music I listen to like Yes and Tom Petty I get the lower registers of the guitars and synths without bloat. I may not get a gut kick but that's what the BagEng Infra-18 in my system is for. I can get "air pressure" bass with the ESS combo for a win.
I bought a pair of AMT 1Bs new back in 1980. I didn’t replace them until 2018! I had to reform the woofer and radiators in 2001. I sold them to my brother for a nominal fee and he still enjoys them today, They were amazing rock and roll speakers. The grand heil was astounding but the bass from a 12 inch woofer and matching passive radiator was powerful. Yes, there was a hole in the mid range around the cross over but this resulted in a natural smiley face EQ of the sound - great for rock and roll. It’s probably not surprising that I replaced them with golden ear triton 5s. They have the same heil type of tweeter and passive radiators!
I had a set of ESS Tempest LS8's bookshelfs and I think they were balance better than the bigger speakers. Replaced the passive radiators after foam rot (about 8 years)and continued to use them until around 1990 or so. I went through and up the NHT line for the next 15 years and now have the Proac studio 140's. The Proac's have a similar top end but with more air and the midrange is in another league. The LS8's were hard to beat for the money back then. I am seeing crazy high prices for their newer speakers which will put them up against some much better options IMO.
I had a pair of ESS bookshelf speakers that I bought in the late 70's or very early 80's. The bass was not tight or deep but pleasant sounding. The thing that struck me about these speakers was their clarity. The tweeters had a crispness to them unlike any tweeter that I had heard previously. But, at the same time, it was smooth and did not have a harsh bright edge to them.
I own a set of ess tower 1. After all the klipsh. And jbls Polk you name it I listen to them all And have a set of 6 speakers that I want part with. Just finished a set of pioneer hpm 200 they sound amazing. But I set and listen to those ess tower 1 and realize they play every kind of music perfect I have two sets of ohm l Nothing seems to grab me like the ess every time I play them for other people that have better and more expensive gear they get speechless. So I will own them for life
Just posting some bragging and maybe a request for some more information, since it's hard to find on the web. Yesterday I scroed a set of ESS AMT-1em speakers. As far as I can tell, they are the last iteration of the monitors that started in the 70s. There's almost nothing on the e model, and it looks like these were from the second coming of ESS that was around in the late 90s-early 2000s. Sound As Clear As Light They have the famous Heil tweeter, a 12" woofer and another 12" passive radiator. Pots on the xover for midrange and treble adjustments appear good. No biamp inputs like the earlier AMT-1d (I think that was the one) had. Surrounds are good, grills, cabinets clean, I'd conservatively give them a VG+ rating. Seriously, I think they were bought, set up, kept clean, and moved when I answered the CL ad. I've hooked them up in the garage- not their final resting place- and they sound fabulous. These are going to be a lot of fun. Best part- I got them for $75. I estimate that's about 1/20 of their market value. It was a weird CL deal- someone else was listing for a middle aged woman who was doing some 'downsizing'. I called and asked her the details, she said she thought they were about five years old, and mentioned something about a husband. I can only guess she's disposing of his things. My gain, I guess.
Those are the ones. Heavy suckers aren't they? Put on Pink Floyd's "The Wall" and turn it up. Incredible as I remember. Incredible price! Nice score.
Much love here. I own a pair of AMT-1 Towers with the transmission line cabinet which are essential for smoothing out the bass response and necessary for rock music. The AMT-3 Rock Monitors also addressed the bass response, effectively.
Funny thing I was just listening to Dark Side of The Moon on my ESS Amt 1's. By the way I Photographed the Cover for Pink Floyd 'Animals"
These were produced in the late 80’s or early 90’s Long Beach California address and plastic input panel.
Basically remember the designs as being poorly integrated from bass to tweeter some sort of disconnect. Hole in the sound---empty sounding. Boring but very high tech. I love treble so I refused to stop with these. Later bought EMIT tweeter bookshelf from Infinity and had to live for years listening to horrid disconnect between tweeter and bass. Wised up. Bought Harbeths.
AMT 3’s solved the midrange issue But still had weak bass. Bracing/ damping the enclosure and replacing the stock woofers with (comparable) modern paper cone woofers that operated in a sealed enclosure... You pretty much have a world class, totally full range speaker...with clean bass @ 28 hz. Acoustic suspension bass has similar transient response to the Great Heil. But it really boils down to balancing the bass output on level with the mids/ Heils...so you have a flat response/ and output. Keeps the Heil from overpowering the rest of the drivers. ie sounding “bright” Posted a lot of info on getting the 3’s up to speed over the years @AK Not that difficult..
Really? Harbeths? Ehhh A dome tweeter that sounds like every other dome... and plastic cone bass...AND thin wall enclosures and dressed in the Emperor's New Clothes... No thanks... But heh heh Sterophile seems to love them!!
I have had a pair of AMT-1 Towers since the late 1970s. They are a transmission line design cabinet which provides superior bass response. No subwoofer necessary. There is no cone woofer on the planet that is as fast and detailed as a Heil AMT. So, there is a miss-match between the transient response of the tweeter and woofer. However, because of the other qualities of the sound that is something that I am very happy to live with. And yes, I also have other high end speakers (JSE Model 2, Tekton Pendragon) to compare with. Additionally, I have them bi-amped to dial-in the precise crossover frequency to my liking. AMT tweeters are appearing on more and more speakers, especially at the high end. BTW I worked in a stereo shop in the 1970s and the ESS AMT-1 Towers clobbered any other speaker in the shop except the EPI M1000 Towers.
While in college in the late 1970s, by friend had a pair of ESS bookshelf speakers with the Heil tweeter. They sounded amazing for hard rock and I wanted a pair so bad. A couple of years later I found a store where I lived that sold ESS and they talked me into a pair of ESS Targa 412-T. While the were large and impressive and had a better balanced sound, they didn't come close to the amazing highs of the bookshelf models (I'm guessing because they had normal dome tweeters). I used them in my main system from around 1980 to 1995 when they became background speakers in my business. By then, the foam was gone on the woofers and passive radiators, but they were fine for background music in a showroom.
Are the current production ESS speakers worth considering? Can’t tell if it’s the original company (or did someone buy the name), but they sure look similar ESS Speakers USA
That's pretty much how I remember them. I still remember that loose, poopy woofer but the "highs" were quite good. More open sound compared the the JBL L100's on the floor of the listening room at the same time.
Sure. The AMT3's bass was far from "poppy"-but on the light side. Modern drivers, modern thinking, modern methods. With the AMT3- adding baffle bracing between the woofer opening/midrange upper woofer opening solved any front baffle resonance. Nothing to hard. A ceramic damping compound was applied to the interior-as well as lining the interior with 1-1/2 egg crate foam. A complete recap-rewire of the crossover-Evo Oils in the high/mid section. Also the stock 3 lbs ea of Dacron stuffing was dumped in favor of 1- piece 1-1/2" eggrate foam + 1-piece 2-1/2" Auralux foam behind the 2 woofer. Weight of each speaker now tops 120+lbs ea. Give you the needed damping without the huge resistive force of filling the box tightly with 3+lbs of Dacron. The now discontinued Orange Count Speakers Eminence 1040SF foam surround/paper cone woofer was substituted for the for stock units-and the small "port" plugged. The speaker now as clean response to 28hz with bass sufficient in level and extension to match up to the other drivers. Sealing the bass-with woofers capable of operating in a sealed enclosure-give you tight full (with 2x10" woofers) bass with a transient response on par with the Heil. The 3-way design-with a sealed midrange-no bass disconnect-midrange hole-or sloppiness-now was a full range sound-no sub woofers needed. Frankly the sound of these "Mojo" modified speakers pretty much blows anything away I have heard the last 50_+ years. Yep they are that good. Very well balanced and highly musical. All the Rock Monitors needed was clean tight bass to match up with the rest of the speaker. Ess wasn't the only manufactor that had difficulties match the bass section with high definiton highs. Klipsch-Martin Logan-Magnepan. Bright sounding speakers.-thin bass. In most cases-take Klipsch-it's not necessarily that the horns are harsh per se. a lot of it can be smoothed over with simply balancing the drivers output response at the listening positions. ESS IMHO made the mistake of using bass reflex-that in the period-was sloppy sounding. With the AMT3-the bass box is really to0 small for most 2x10" woofers in a ported enclosure-even to small for most 2xwoofers in a sealed enclosure-but the 1040SF's were the only woofer I found that provided a flat/deep response with the stock dimensions.
Here's a pair for sale at Echo Audio in Portland OR, for anyone looking for a set. Echo Audio | ESS Laboratories AMT 10
