And your impression of the sound?
The Original 10" ESS AMT1 Full Restoration, Alnico Re-cone. Heil Restoration.
I know that my JBL PR15s have weights that you add/subtract for the correct mass loading per application, didn't see anything like that on the Bextrene PRs though, you'd need to add putty or something to increase mass I believe.
Sure.
The new drop in should be tuned. As they were put in different volumes.
I would imagine ESS tuned the old Bextrines during manufacture-but hard to say for sure.
I know Ricky has has little info on the AMT3's-and was for a time recommending the 4 ohm replacement woofers for the 3's.
Only a certain run had 4 ohm woofers-the give away is the 4 coil crossover and 12 resistor Zobel.
The new drop in should be tuned. As they were put in different volumes.
I would imagine ESS tuned the old Bextrines during manufacture-but hard to say for sure.
I know Ricky has has little info on the AMT3's-and was for a time recommending the 4 ohm replacement woofers for the 3's.
Only a certain run had 4 ohm woofers-the give away is the 4 coil crossover and 12 resistor Zobel.
jcidave
Well-Known Member
The stamped frame ceramic magnet woofers that came out of these were real no name and had no ESS model markings on them. I have not played these with the new woofers segregated from the rest of the system. So they sound about the same. Sorry I am not of more help. This was a something to do project.
Just from my take-and a look at reviews, and comments here-I'm sure the new Ess woofers are adequate-and work with the old cabinets.
And are using modern methods of construction/etc.
For the round woofer AMT1's the Misco Legacy 10" 4 ohm woofer seems to work well-and is well designed. Nice low inductance-and extended response figures.
1.5" voice coil mimics the O.E.-but it should be able to take plenty of power the ratings are conservative.
No flag waving here- but it's nice it IS manufactured here in the US-with a local appreciation for ":Legacy" speakers-and using state of the art manufacturing/testing techniques.
https://store.miscospeakers.com/10-inch-woofer-93053
And are using modern methods of construction/etc.
For the round woofer AMT1's the Misco Legacy 10" 4 ohm woofer seems to work well-and is well designed. Nice low inductance-and extended response figures.
1.5" voice coil mimics the O.E.-but it should be able to take plenty of power the ratings are conservative.
No flag waving here- but it's nice it IS manufactured here in the US-with a local appreciation for ":Legacy" speakers-and using state of the art manufacturing/testing techniques.
https://store.miscospeakers.com/10-inch-woofer-93053
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No.
There are "black" Heils, where the metal "fingers" are painted black (current offerings and some past models), then there are "black" Heils where there are what appear to be black rubber "overlays" that lie on the plates and the "fingers" are black plastic (AMT 1D).
Silver Plates (could be painted black):
Later Painted Plates (notice the plate count is way down):
AMT 1D Plates (like on the Ethyl Mermans except with the standard bolt heads on top as on the silver plates):
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Might look like this inside?
These are the Heils on my V5/ 1980s AMT Monitors, black with the high plate count of the silver ones pictures above, and note the rubber wedge below it..
Our V3 Heils are black also, look identical. Original woofer partially visible on top:
Our V3 Heils are black also, look identical. Original woofer partially visible on top:
This was out of one pair of my 3's
Output was down roughly 2db from the other speaker.
Replaced both with new productions.
As mentioned-they have a higher output.
Originally turned l-pad to "soft".
They seem to have some break-in period, and seemed to even out-and now I have the setting at "normal".
Willy's hifi offers 4 ohm l-pads, so one could easily fine tune their Great Heil-more then the simple 3-way padding.
I purchased a set for my second pair.
Some people have issue with l-pads-unless they are dirty-or malfunctioning in some way-I have never heard a audible difference.
Some pretty hi-end speakers over the years have them, even still today.
Their convenience-when needed is well worth it. I run them back and forth on occasion to keep them clean. If they fail-easy and inexpensive to replace.
Same goes for the fuse-cheap insurance as well.
And never heard a audible difference.
But ideally, and is a good practice in general-less in the signal path-less to go awry.
https://willys-hifi.com/collections/l-pad-attenuators/products/4-ohm-l-pad-attenuator-50-watts
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That picture / diaphragm is from one of mine, the pair I bought a couple of years ago used.
BilboBaggins
Addicted Member
Interesting thread! I read it through from start to finish just now because I have a pair of AMT4s. I bought them because I believe they use the same woofer as the AMT1, which I've had twice now and really like. I've also had a pair of AMT 1aM, which went louder, but I didn't like as much as the AMT1s. So eventually, I will start experimenting with these AMT4. So far I'm really not that impressed by them, but I think they need some TLC.
Interestingly, this version of AMT uses a 2/3 sized Heil Transformer.
Having the 10 inch woofer upgrade option from ESS is definitely an option I am considering!
Interestingly, this version of AMT uses a 2/3 sized Heil Transformer.
Having the 10 inch woofer upgrade option from ESS is definitely an option I am considering!
jcidave
Well-Known Member
I also have AMT4s with the cut down version of the great Heil. At the ESS dealer I worked at in the 70s, we had this version of the AMT4 out for demo and later the AMT4 with the dual plate version of the Heil. I thought this was a great small floorstanding speaker. The sleeper in the ESS lineup. I am pretty sure the 4s xover at 1000hz instead of 700 hz like the 1s. I also thought they used the same 10 inch woofer. But, if you look at the schematics on the ESS website, the part numbers for the AMT1 and AMT4 woofers are not the same. I also have AMT1s and AMT1a Monitors. To my ears my AMT1aMonitors have the best deep bass in my collection of ESS Heil speakers. I believe the 1aMonitors also xover at 1000hz.
Were not the AMT4's a sealed system?
I think the AMT1's were all ported.
Not that you couldn't have a woofers who's EBP is in the middle range-works with both sealed and ported.
Always have liked the AMT4, and have been looking for a pair locally for years.
No way I would have these shipped unless they were on pallets!!
BilboBaggins
Addicted Member
You are right, the AMT1s are ported on the bottom. I was so excited at an option. And it may still be an option. What I am reading between the lines is that contacting Ricky to discuss the AMT4 woofer just might lead somewhere.
Yeah, I wouldn't ship them either. the AMT could get damaged.
BilboBaggins
Addicted Member
I did find my AMT 1aM Towers to be a little bass light. I much preferred the Kef 105s bass. However I did really like the AMT1 pedestals. They just didn't really suit the room. They are one of a very few speakers which work well in the living room. Bummer about the woofers having different part numbers. And if you, with experience, think the 4 might be better than the 1, then I am definitely going to give the 4 a fair chance. For the moment, they sit there waiting waiting their turn.
Sure-well the new ESS woofer might work-a EBP number-or full specs you could figure it out.
This woofer would work well either sealed
https://store.miscospeakers.com/10-inch-woofer-93053
Disregard the model #'s-gives you a rough idea of how the EBP numbers work.
A few members have used this in their AMT1's with excellent luck
Great specs and made locally.
A real throwback-like the discontinued Eminence 1040SF
1 1/2 copper voice coil/ polymide former/cotton spider, ploy ether surround and American pulp cone-couldn't ask for more IMHO. Perfect compliment to the Great Heil!
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jcidave
Well-Known Member
Damage? Yeah there can be damage. My AMT 4s as they arrived from Audio Classics. However, all put together and working. Didnt have to buy new diaphragms.
