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ESS AMT-3 replacement woofer candidates

And reading another thread-Gordon W makes some good points concerning capacitor replacement.
And I have found the same things modding the AMT3's over the years-too much stuff, and you end up destroying the original speakers sounds you liked so much to begin with-despite those drawback you were trying to correct.
That's why I would be very careful about randomly throwing caps at speakers-unless you have a lot of money to blow-and time on your hands.
Luckily the Mundorf's seemed to have worked well-they don't change anything too drastically-just smooth and separate.
That's why I can confidently recommend it-even with break-in I can't see anything changing much.
But at the same time-if you go back to new electrolytes-or a basic poly cap, like the Dayton's Erse PulseX-Jatzen Crosscap -it's no biggie. Your staying closer to original. Those caps don't try to do anything, except be a cap.
I think I mentioned-I had one AMT3 owner PM me saying he went back to the original Electrolytics on his-because the poly's didn't sound right to him. Something to consider.
I think some of the caps enthusiast here put out some misinformation that's not helpful.
That any expensive, high voltage cap IS 'better' then a basic poly, electrolytic. That's simply not true in every application.
They should stick to specific applications were they put the caps-i.e AMT3's-and refrain from those broad brush statements.
Were all guilty of it at times-but when it goes on, and on-site to site, it's pretty crappy IMHO.
 
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automojo said:
I think some of the caps enthusiast here put out some misinformation that's not helpful.
That any expensive, high voltage cap IS 'better' then a basic poly, electrolytic. That's simply not true in every application.
They should stick to specific applications were they put the caps-i.e AMT3's-and refrain from those broad brush statements.
Click to expand...

In my case, I spent hours and hours researching on the net, trying to narrow down capacitor choices. Reading articles, trials, tests, reviews, and word of mouth recommendations. Plus, pouring over all the capacitors for sale at multiple sites. I even requested advise from the designer of SoniCaps, and what he'd suggest for my AR-90's, at my budget. That resulted in my use of a mix of Mundorf caps.

I've also started on a test of various other bands of capacitors. Different caps, for my other AR speakers. Speakers that all share the same tweeters and midrange drivers, and very similar woofers. Even the crossover designs and parts requirements are almost identical. That sets-up the ability to directly A/B the different capacitors to one another.

So, if I suggest that capacitors do sound different to each other, it's from direct comparison, and not a belief that cheap caps are junk, and you have to spend a minimum dollar amount, to reach sonic nirvana. I think there are others who have experimented as well, and are just trying to pass on what they've learned. As such, suggesting cap A over cap B, isn't audio snobbery. We're only trying to help others make informed choices.
 
I will say that the caps do make a difference on the Heils. I used 3.3 Aerovox and they were very bright..., maybe too bright. I changed to 3.3 Claritycaps, and they lost the brightness, and maybe could be a bit brighter.

I picked a ~4KHz crossover frequency for a couple reasons. The Heil has a natural dip at ~5K, and continually gets brighter from there with frequency, so crossing over at ~4K actually starts the crossover a bit higher than 4K taking advantage of this dip. The "wedgies" flatten the upper frequency boost such that the "tweeter" is fairly linear over it frequency range.

The 2251J 10" (actually ~9-3/4") goes this high before it gets rough.

I prefer to keep the midrange in the midrange driver and the highs in the Heil rather than split it up between two drivers where the Heils takes care of the upper mids and the highs. With a lower crossover point to the Heils, when one wants to reduce the highs in the Heils they also end up reducing the midrange. At ~4-5kHz for the bottom end, the Heil is not seeing the major fundamentals, but mostly overtones and shimmer.

ScreenHunter_211_Jul_30_11_40.jpg
 
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Sure-I don't think any of it's snobbery.
And in your case, your doing thoughtful research.
And it makes sense to apply to specific models.
And you obviously had a idea of what you were specifically trying to change.
It's some of the others post's I have seen that don't make a ton of sense. Broad brush-large encompassing statements.
Nor does the person randomly swapping a cap as a shot in the dark-because that cap, in general terms, is supposed to be better on paper.
Or someone saying you can't use Solens in a high pass-dumb stuff like that.
And yes-do your research for sure.
People are obviously free to post as they please-do what they want, I just find some of it strange.
I feel bad about my first experience swapping the Mundorf's-and that mis information but at least tried to 'own up' to my error-and correct the misinformation as best I could. it was a dumb over site on my part. IS what is.
Not saying I'm better-worse etc, just trying to be as accurate, in a sort of scientific way as possible.
 
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toddalin said:
I will say that the caps do make a difference on the Heils. I used 3.3 Aerovox and they were very bright..., maybe too bright. I changed to 3.3 Claritycaps, and they lost the brightness, and maybe could be a bit brighter.

I picked a ~4KHz crossover frequency for a couple reasons. The Heil has a natural dip at ~5K, and continually gets brighter from there with frequency, so crossing over at ~4K actually starts the crossover a bit higher than 4K taking advantage of this dip. The "wedgies" flatten the upper frequency boost such that the "tweeter" is fairly linear over it frequency range.

The 2251J 10" (actually ~9-3/4") goes this high before it gets rough.

I prefer to keep the midrange in the midrange driver and the highs in the Heil rather than split it up between two drivers where the Heils takes care of the upper mids and the highs. With a lower crossover point to the Heils, when one wants to reduce the highs in the Heils they also end up reducing the midrange. At ~4-5kHz for the bottom end, the Heil is not seeing the major fundamentals, but mostly overtones and shimmer.

ScreenHunter_211_Jul_30_11_40.jpg
Click to expand...
Nice!
I'm sure these thing can be improved on-I like the end result with my AMT3's-no real complaints-frankly they sound fantastic.
If I was going to design a 3 way Great Heil, I would use the Audax PR170m, as the mid-1040sf's as the woofers, and bring the crossover point to a more traditional point that takes advantages of the real pluses of each driver.
In my Mojo mods-that wasn't the goal-to redesign, but work with the original design.
 
The Mundorf's seem to be bright-but not in a harsh way, because you can hear way more layering, and space.
The Audyn's started out kind of bright-brighter then I remember the Dayton's-but I didn't have enough time on them. They just didn't sound well sorted out-if that makes sense-compared to my well broken in Dayton's.
The break-in part-I don't get totally-some of it I have to think is conditioning-the other part-seems unquantifiable for the most part.
 
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Well, I have spent the last few weeks replacing the ancient Alpha 6As with a newer pair offered to me by a forum member. I was also able to rebuild both sets of crossovers and have been doing some detail listening. The Heil is definitely too hot even in the Soft position. There are at times spectacular results but sometimes the sibilance is too much. Based on the data out there, there is apparently peaks at 5K and 12K that need to be equalized.

https://www.diyaudio.com/forums/multi-way/334601-ess-amt-tweeter-help-correct-5.html

I am going to pad the Heil down slightly and maybe try some of the techniques mentioned in the above thread if I get unsatisfactory results. Other than the sibilance, the speakers sound very good. Its very different than the Altecs and the Tannoy and does not play anywhere close to their volume, but I like them. Meanwhile here are some pictures of my rebuilt 3 coil AMT 3 crossovers using AXON caps.

IMG_3187.JPG IMG_3207.JPG
 
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Nice.
IMHO a lot of this is equipment dependent, as well as listening room dependent.
With my current set up-in my living room system-Proton AP1000, H/KPA2400 (most times I run analog, and usually digital through a Grant Fidelity DAC-09, (and the Mundorf Aluminum Oil Caps)-but even when running 'straight', so to speak, I don't hear any sibilance, nor think the Heil is too loud vs the rest of the drivers.
Everything sounds fairly natural, and very musical.
The Mundrof's smooth the response of the Heil, especially with early cd's from the 80's.
Any equipment in the chain that has a bright tendency might be a bit too much-although for years I ran a PT2300 preamp that was on the bright side, and ran the Heils on soft-in my old listening room.
I'm not sure what your looking for db peaks/loudness.
They need plenty of clean power to play loud.
With the 1040SF's, stock mids-they play very clean-unless you have a DB meter-you may not realize how loud they actually are-because the Heil doesn't compress like most drivers, especially horns, that get that funky dispersion pattern/beaming right before they loose control, that makes them sound harsh, etc.
In my second system, I run a Signature (Madigril) that will easily do 350 watts continuous into 4 ohms-very transparent and uncolored-and they can make the 3's thunder, but cleanly.
Personally, I would swap in some Mundorf's before I started messing with the crossover points-as IMHO your loosing the benefits of the Great Heil covering a larger range of the mids on up-my opinion of course.
Some prefer running them simply as tweeters, or super tweeters.
Or maybe try/borrow and electronic crossover and play with the different points.
I have been messing with these speakers for years-but always lean something new-with swaps, etc.
The Mundorf's to my surprise was a excellent one-and is on level with the 1040sf/sealed enclosure swap.
I also [refer the stock mid-over the Alpha 6A.
IMHO it didn't sound as natural-and I couldn't really find a satisfactory balance with the L-pad.
This is my opinion of the AMT3's-the main issue I had was the lack of balance on the lower end-the mids and high's-with the right driving equipment where more than satisfactory, life like, and musical. Perfect-no, but better then most I have run across, and they don't over power a decent size room-but when set up right-really blend in and make the best of your situation. Being sealed improves this.
Overall, I was able to enhance the AMT3's without changing there overall voicing, or detail. Just evening things out.
Sure wasn't easy.
And they, in their current Auto form, play very evenly at low volumes levels-like the stock 3's, so you get the same detail across the musical spectrum-increasing the volume doesn't change this balance.
The PS1220's and AMT3's are one of the few speakers I have run across that can pull this off, that doesn't cost 3-4K on up.
I look forward to seeing where your AMT3 project end up.
 
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Automojo, I listened for several hours yesterday using audiophile quality CDs as well as Paul Simon's Graceland CD. Not too much Sibilance at all with these disks and the speakers sound very good. Perhaps the caps and the drivers need to be "burned-in" and settle down before anymore adjustments. I will let it cook awhile before I report back. The next step is to fix the cosmetics, including redoing the grill and make new grill boards as the old ones have literally disintegrated.

The system I am using to cook them. This is NOT a bright system. The speakers are place literally in the middle of the room with no bass reinforcements whatsover. Speaker placement might be the next step as well.

Monster Cable AVS2000 voltage regulator
NAD M55 Master Series Universal Player
REGA Planar 3 turntable with Elys cartridge or Thorens TD125 AB mark 1 with TP12 arm and Shure V15 type 4
Bedini 100/100 Mark 2 power amplifier
Conrad Johnson PV6 modified. Phono section has Dynamicaps, Line section has Mundorf Silver Oils. This is a killer Preamp with the cap upgrade and its a steal.
 
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Automojo:

I know you wanted the Eminence 1040SF woofers, but the reason I did not go with them is that they are no longer available (remember the 1240sf and 1040sf confusion?). If they were, I would have used them with the Alpha 6As. As far as the Great Heil equalization circuit mentioned in the link I provided earlier, which yields a dip at 5KHz... I tried that on my main system, which crossover to the great Heil stack at 4KHz using digital EQ and the results were very positive. To my surprise the system sounded noticibly smoother. I only reduced the 5Khz peak by 3.0db with a narrow Q. So it looks like the "tweak" suggested is worthwhile. To those who want to try it in a passive fashion, I am including a copy of the schematic for those interested. The RLC circuit in parallel with the Heil is the one we should be focusing on: L3, C3 and R3. L2 is an option only.

Kwing

744971d1553379713-ess-amt-tweeter-help-correct-amt-heil_2-3khz_-png
 
It would be a interesting experiment for sure, I might play around with it at some point.
Right now I have everything level matched on my first pair of 3's so I would skip it on those.
Might be something for the second pair-although I never really hear any semblance-on z'-t's s's, etc.
I still have to wonder if a lot of this is equipment, cap, listening room, and of course ear dependent.
Also if your drivers aren't truly level matched-your going to hear thing you normally don't hear, similar to tuning a woofer to a bass enclosure, where certain frequencies are more dominate.
What one should do is measure the frequency of the Heil through the stock crossover-and then see if correcting would be helpful.
FIY-I realize the 1040SF's are no longer available.
If you decided to go with them or not-if they were-that would be your choice-it would not matter to me one iota, so to speak.
But it's great you found a currently available woofer that seems to work well-awesome!
 
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StimpyWan said:
That I'd love to hear...! :biggrin:
Click to expand...
The Conrad Johnson PV6 was the first piece of equipment I recapped. I settled on the Dynamicaps on the phono stage because using all Mundorf silver oils made the preamp sound TOO lush. Back then these caps were much less expensive than they are today so it was expensive but not overly so. Other caps I have first hand experience with include Mundorf Aluminum Oil, Mundorf MCAPs, Soniccaps, Audiocap Theta, AXON, Solens, Dayton, Audyn, Jantzen, Jensen, Spragues and VCAPs. I learned a lot from these experiments and the Mundorf Oils are the best sounding to me...and worth the $$. The CJ PV5 and PV6 are really good sounding preamps that you can pick up for less than $1K. The Audible Illusions Modulus 3A should also be considered.
 
automojo said:
It would be a interesting experiment for sure, I might play around with it at some point.
Right now I have everything level matched on my first pair of 3's so I would skip it on those.
Might be something for the second pair-although I never really hear any semblance-on z'-t's s's, etc.
I still have to wonder if a lot of this is equipment, cap, listening room, and of course ear dependent.
Also if your drivers aren't truly level matched-your going to hear thing you normally don't hear, similar to tuning a woofer to a bass enclosure, where certain frequencies are more dominate.
What one should do is measure the frequency of the Heil through the stock crossover-and then see if correcting would be helpful.
FIY-I realize the 1040SF's are no longer available.
If you decided to go with them or not-if they were-that would be your choice-it would not matter to me one iota, so to speak.
But it's great you found a currently available woofer that seems to work well-awesome!
Click to expand...

Mojo:
For sure if the 1040SFs were available I would have used them instead of the Daytons, especially at the insane price of $49 each vs $89 for the Daytons.... I did not want to reinvent the wheel. Right now at least I am happy with the Daytons but I am not yet done tweaking....
 
kwingylee said:
The Conrad Johnson PV6 was the first piece of equipment I recapped. I settled on the Dynamicaps on the phono stage because using all Mundorf silver oils made the preamp sound TOO lush. Back then these caps were much less expensive than they are today so it was expensive but not overly so. Other caps I have first hand experience with include Mundorf Aluminum Oil, Mundorf MCAPs, Soniccaps, Audiocap Theta, AXON, Solens, Dayton, Audyn, Jantzen, Jensen, Spragues and VCAPs. I learned a lot from these experiments and the Mundorf Oils are the best sounding to me...and worth the $$. The CJ PV5 and PV6 are really good sounding preamps that you can pick up for less than $1K. The Audible Illusions Modulus 3A should also be considered.
Click to expand...

I haven't yet tested that wide of a variety of capacitors. But, I'm working towards it. Fun to compare.

I do like the Mundorf caps I've tried. EVO Oil's, Supreme's, and Supreme Silver/Oil's. I got a deal on some S/O 2.2uF's, otherwise I wouldn't have spent that much. Also, surprising at how clean and clear they are. Very transparent.

On, we used to have a CJ PV5 and a MV45 at work. Very sweet. Talk about TOO lush...! But in a good way. :)
 
Stimpy:

CJ PV5 and MV45 would be a nice combo. I have the MV55 to go with my PV6. I used to have a MV50 but I sold it and bought the MV55 because I mistakenly trusted a professional reviewer's opinion instead of my own ears. The MV55 is good but I miss the MV50. The MV50 is a direct descendant of the MV45.
 
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Automojo, do you mind posting (or send to me privately) a short clip of your AMT3s playing popular music? I just want to get a sense of what the tonal balance of other AMT3s. Let me know if that is possible.
The restoral of my AMT-1Cs has turned into a giant flop. Both refoamed woofers sound bad. I suspect one has damage to its voice coil and its distorting like crazy. Time to either recone, or replace them....
 
Want to give an update on this.. I have completed the restoration of my AMT 3s with the Dayton RS-270P 10" woofers as I have described. I even used the original 70s style AMT 3 grill cloth but stapled over newly fabricated substrate. I also completed the electrical restoration of my ESS AMT-1Cs. I have been comparing their sound signatures over the last several weeks. While they both have the clear as light sound, there is no doubt that the AMT 3 is cleaner and more balance while the maximum SPL achieved by both systems are similar. The AMT-3 also has more punchy bass. At this point, I can unequivocally recommend the Daytons as a very viable alternative woofer system for the AMT-3 for those that need new woofers. The only downside is that unless you get them on sale from Parts Express, they are more pricey than the other alternatives suggested by automojo and others.
 
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@kwingylee Hey, I'm going to get a set of 4 of the Dayton RS-270P 10's for my AMT3's. Should I get the 8, or 4 ohm models? I know that the AMT3's have several variations, how do I go about telling which speakers I need to get?
 
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