ESS AMT 3 Crossover Schematic

Bass Box Pro 6
Part of the reason in tuning the Daytons lower, If you tune them to high, close to fs, The ports are pushing out major amounts of air at 41hz, and the cones don't seem under proper control.
Way to much bass at 41hz. Cone output, along with the port output, is enough to give you a headache!!
Perhaps they handle more power at this high tuning frequency but the sound isn't the best.
It's not like I'm going to use them for sound reinforcement.
They will play clean as loud as your ears can stand, without any issues.
I started looking at how low Tekton tunes their pro woofers, and realized I had to go with the flattest response.
The woofers are only going to play frequencies as low as they are designed.
The port is only going to contribute the lower frequencies, not the woofers themselves. The combination of the box tuning and ports allows you to have a lower frequency response/ extension then possible with a sealed system.
The heavy damping keeps everything smooth and under control, no port junk, or standing waves, and drops the Daytons output slightly, to integrate better with the other drivers.
It's surprising you would almost think they are a sealed system pretty amazing, tight response, but way more efficient.
 

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Four coil crossover- 4ohm woofers, Peerless midbass
 

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The early models, where 4 coill 4 ohm version, and most had peerless midbass. They also had a larger mid-tube. Nelson Pass was involved in the earliest version.
The later three coil versions used 8 ohm woofers, foam surround midbass, and generally most of these have the smaller mud tube, but not all.
Some versions ported and some not.
Both of the non-ported version seem to be earlier models
Given the heavy damping, the port mainly reduces internal system pressure. It's way to small to act like a port in a traditional vented speaker, resistive damping.
All AMT 3's used active woofers.
Both versions had some sort of printed circuit board but not all .
It shouldn't be too hard to figure out how the woofers are connected, you only have one set of wires coming from the crossover.
It's pretty simple - 4 coil 4 ohm woofers, 3 coil 8 ohm woofers.
Freshen up the crossovers and the cabinet reinstall, and enjoy.
If you're starting from scratch, go with the crossover I will go with the three coil unit.
Presents a lot less resistance and more efficient.
If you don't have the original woofers, you'll have to experiment just like I did.
Get yourself a copy of bass box pro and have fun.
I had the original woofers, but wasn't happy with the bass.
But that's just me, you need to formulate your own opinion.
 
Them coils is much nicer than factory original. Mind disclosing what it cost to have them made?
Just buying the magnet wire and winding them yourself can put a dent in the bank account.
 
The smaller coils are PE supplied.
The larger coil's were from meniscus Audio.
They don't make custom coils anymore .
They were roughly in the $20 range as I recall.
 
I think the main thing if you're going custom, is go with largest gauge you can find
I also don't rely on the old stock switches, fuse holders, input terminals etc.
They are 40 plus years old and corroded.
Not worth messing around with
 
I think the main thing if you're going custom, is go with largest gauge you can find
I also don't rely on the old stock switches, fuse holders, input terminals etc.
They are 40 plus years old and corroded.
Not worth messing around with
The other parts are pretty easy to find at Parts Express or digikey, but I'll take this opportunity to post a link that some guy sent me for the rotary switch:

https://www.digikey.com/product-detail/en/nkk-switches/HS13Y-D/360-2350-ND/2039688

HS13Y-D.JPG
 
The ESS owner is Ricky Caudillo. The factory is local to me near Los Angeles. I know him personally. Let me know if I can help with any ESS issues.
Thanks.
 
Well it's been awhile since I last posted about my quest in restoring these classic ESS AMT 3 Rock Monitors. I drove up to Maine to visit my father and my brother to celebrate my father's 92nd birthday. On the trip I recovered the AMT 3 cabinets that I couldn't fit in the car on the last trip. These are the cabinets that had the 679-1111 woofers in them originally. To my surprise I saw in the original wiring there are two jumper wires with spade (female) connectors on each end, meaning the woofers were hooked up in parallel. In series the woofers would only need one jumper plus the plus and minus from the crossover. What is concerning to me is that the original 679-1111 woofers show 3.2 ohms across them. The crossover is the different from my other set and is the same crossover that they use with the 680-0010 woofers. I'll post pictures soon.
 
First pics are the ones I just brought back from Maine with the 679-1111 woofers. The second picture is from a set that originally started this quest. I'm transferring all the components over to the Maine cabinets because they are in a lot better shape. I've already made up new grills for them with new cloth and I've ordered new capacitors(to spec) to renew the crossovers. I will update with new photos when finished.
 
First pics are the ones I just brought back from Maine with the 679-1111 woofers. The second picture is from a set that originally started this quest. I'm transferring all the components over to the Maine cabinets because they are in a lot better shape. I've already made up new grills for them with new cloth and I've ordered new capacitors(to spec) to renew the crossovers. I will update with new photos when finished.
The upper one looks like the crossover from the schematic at the beginning of the thread. The lower one looks different. Is there a fourth coil attached somewhere else in the enclosure?
 
Sure..
Well the pictures are hard to look at their fairly dark but I think you have two different models from your description.
3 and 4 coil.
 
image.jpeg image.jpeg The big point to me is that the 679-1111 3.2 ohms and the 680-0010 5.2 ohms from what you posted automojo image.jpeg are both using the same crossover. In both cases the two active woofers are hooked up in parallel.
 
Sorry posted the jumper wire pic twice. All pieces are original to the cabinets. I wrote to ESS again but haven't heard back from them. I like to try that you posted a picture of automojo. Did you post a schematic for it?
 
Yes, they are all wired that way, 3 coil and 4 coil AMT3's. 3 coil uses 8 ohm woofers. 4 coil uses 4 ohm woofers. You can't swap either, woofers, as it throws your crossover off a octave, among other things.
 
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