Ess amt 1b

Johnlw7

Active Member
After a long dry spell finally made a decent score on some speakers.Was a local moving sale and picked up a nice pair of ESS AMT 1B speakers.Spotted them walking up the driveway,my heart was pounding and I was hoping they had not been sold.The woofers and passives need refoamed.the tweeters are in excellent shape.From what i have read and been told they are great speakers.Anyone here have a pair.Would appreciate some info.
 
After a long dry spell finally made a decent score on some speakers.Was a local moving sale and picked up a nice pair of ESS AMT 1B speakers.Spotted them walking up the driveway,my heart was pounding and I was hoping they had not been sold.The woofers and passives need refoamed.the tweeters are in excellent shape.From what i have read and been told they are great speakers.Anyone here have a pair.Would appreciate some info.

I have a pair of the AMT-1b (small b) bookshelf version bought original in 78 still sound good to me. I'm in the process of recapping them - the foam was re-done, pretty straight forward re-foam. 6 Ohm load...

Good luck with yours. The tweets go for decent $$ on ebay.

Cheers,
Bob
 
I had AMT-1's similar but no passive, wicked sounding tweeters!!

AND the Heils themselves are worth about $400bux on ebay!
 
Here is what you should do with these: Remove the AMT and place it on TOP of the speaker, so it becomes open-baffle. Mount a mid-range driver where the AMT was. Replace the crossover with a 3-way crossover, tuned to your midrange of choice, and letting the AMTs kick in at a higher frequency, NOT in the middle of the "human voice range". Your speaker will catapult to a whole new league of sound quality.

Putting those AMTs inside the box to act as front-radiators only, was one of the stupidest things ESS ever did.

I love those 1B bookshelf speakers, though: they go for significantly less $$ than the other models with the AMTs mounted on top, so when you are looking for AMT drivers, they are the best bargains around! You can remove the AMT and use it in another speaker (in my case, I'm collecting/saving them to make an AMT open-baffle line Array, with nine AMTs per side :D), and convert the remainder of the old bookshelf speakers into decent Econowaves! With luck, you can sell the Econowave creations for enough to get back your investment, and have the AMTs for free (or at least cheap). :banana:
 
I had the AMT 1B. I took the Heil and now use it on my main system as a super tweeter. Then I refirbed the cabs, refoamed the PR, turned them into eWaves, and sold them. Great speakers though. The only thing I don't like about them is that they are thin sounding in the midrange.

If you go to the eWave thread and look at the first page for member project number 11
 
Just to be on the same page this is what they look like.got them for the price of a case of good beer.So the passive radiator is supposed to face you?I still have the styrofoam pieces.Do they still use that for the PR?I think I will try to restore them to original specs and see what happens.
 

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The PR faces backwards. You can get replacement PR from many places, like simply speakers or orange county speakers. When you get them, glue 4 quarters to the middle of the inside of the PR: that is the same weight as the wood block ESS used but does not come with the replacements.
 
Just to be on the same page this is what they look like.got them for the price of a case of good beer.So the passive radiator is supposed to face you?I still have the styrofoam pieces.Do they still use that for the PR?I think I will try to restore them to original specs and see what happens.

Yup those are the 1A or 1B model - I've got the boxed in version 1b (small 'b') as Arkey suggested my tweets are "boxed" in and not on top. Ah well....

Still good and yours are good too.

Cheers,
Bob
 
I had the AMT 1B. I took the Heil and now use it on my main system as a super tweeter. Then I refirbed the cabs, refoamed the PR, turned them into eWaves, and sold them. Great speakers though. The only thing I don't like about them is that they are thin sounding in the midrange.

If you go to the eWave thread and look at the first page for member project number 11

That was the weakness of the 2 way Heil design. The only ESS models I know that used a midrange were the PS 1220's, which I owned, and should have neve got rid of, and the AMT3's-which I just purchased recently.
MAny ESS fans claim the AMT#'s are the best of the bunch do to 2 smaller driven (10") woofers, and the midrange driver, to let the Heil operate in it's best range.
The PS 1220's were awesome speakers, the louder you played them, seamingly the cleaner the sounded-if the AMT#'s are close to those I will be happy.
The PS 1220's used a 12" bextrine woofer and passive slab (no blockes or weights- the bass never sounded slow or disjointed as some claim with some ESS designs. They also used a smaller Heil-in a 12lb magnet structure.
Perhaps the best route would have been to add a midrange similair to the AMT3's.
 
The b in amt-1b doesn't stand for box or bookshelf. There's an amt-1b floorstander as well as an amt-1b bookshelf. Photos on request.

They're great speakers, especially for their day (more than 30 years ago) and well worth restoring, but they do have quirks, which would take a longwinded pile of subtechnical blablabla to explain. Fortunately, there's a way to get around the quirks: listen to the speakers well away from any walls and make sure your ears face the woofers more or less on-axis. This may require raising the speakers on tables or blocks. Listen to anyone who tells you to add mass, preferably in the form of sheet metal (coins qualify), to the passive radiators to tune the box lower.

After that you can re-line the cabinet, seal the woofer, deOxIT the controls, etc. etc. Easy stuff first.
 
I had the AMT 1B. I took the Heil and now use it on my main system as a super tweeter. Then I refirbed the cabs, refoamed the PR, turned them into eWaves, and sold them. Great speakers though. The only thing I don't like about them is that they are thin sounding in the midrange.

If you go to the eWave thread and look at the first page for member project number 11
Hey DJ, I'm about to use the Heil as a super tweeter, also. I'm curious, what crossover point do you use for the Heil?
 
The b in amt-1b doesn't stand for box or bookshelf. There's an amt-1b floorstander as well as an amt-1b bookshelf. Photos on request.

They're great speakers, especially for their day (more than 30 years ago) and well worth restoring, but they do have quirks, which would take a longwinded pile of subtechnical blablabla to explain. Fortunately, there's a way to get around the quirks: listen to the speakers well away from any walls and make sure your ears face the woofers more or less on-axis. This may require raising the speakers on tables or blocks. Listen to anyone who tells you to add mass, preferably in the form of sheet metal (coins qualify), to the passive radiators to tune the box lower.

After that you can re-line the cabinet, seal the woofer, deOxIT the controls, etc. etc. Easy stuff first.

AMT-1b and an AMT-1B - those are 2 different speakers...which was why I suggested the "small b" above. OP posted a pick of what looks like a AMT-1A or 1B but not a "1b"

Here's a pic of a 1b, Oh and BTW on the back of the crossover is printed: "AMT-1b BOOKSHELF"

Mine have the bextrene woofers but I had bought a replacement a while back with I think a paper cone (in the pic), I've since replaced that one with a bextrene coned woofer.

Cheers,
Bob
 

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Hey DJ, I'm about to use the Heil as a super tweeter, also. I'm curious, what crossover point do you use for the Heil?

I am crossing at 5k from my 350hz Edgarhorns. I have an active xover and have set it from 4K to 9K but 5k seems to sound the best. Well out of the vocal range. They are the best tweeters I've ever heard. Good luck.
 
I am crossing at 5k from my 350hz Edgarhorns. I have an active xover and have set it from 4K to 9K but 5k seems to sound the best. Well out of the vocal range. They are the best tweeters I've ever heard. Good luck.
Thanks, I recently heard the Edgarhorns for the first time. They were attached to JBL large format drivers (2441, maybe?). That might have been expensive (for me) intro to tractix horns. :D

The Heil has augmented a few pairs of speaks over here and has always been a good performer.
 
I'm restoring a pair of the AMT-1 without the passive. refoaming was simple, now I am looking at recapping the crossover, any words of wisdom on this subject? Seem hard to get to. I have all of 20 beans into these so far.. SA find.
 
Hey folks. Nube to this site. Just bought a pair of ESS AMT 1b from a trusted, retired doctor for a song. And I can't sing! All looks very good, cabinets and even the foam surrounds. Planning to refurb. Haven't hooked them up yet but was hoping you could tell me what the heck I have! Haven't seen this driver configuration anywhere. I have suspicions based on my research but would appreciate being informed by those who know ESS. All refurb input welcomed.
 

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Hey folks. Nube to this site. Just bought a pair of ESS AMT 1b from a trusted, retired doctor for a song. And I can't sing! All looks very good, cabinets and even the foam surrounds. Planning to refurb. Haven't hooked them up yet but was hoping you could tell me what the heck I have! Haven't seen this driver configuration anywhere. I have suspicions based on my research but would appreciate being informed by those who know ESS. All refurb input welcomed.


Looks custom to me. Have you opened it up to look inside the cabinet to see if the drivers are separated or share a common airspace?
 
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