ESS HEIL membranes

[automojo]

El Seven..you are wrong about 1 point...I just had them redo my woofers and radiators..and Rico watched my build thread...asked me if that was me putting all the pictures up...so yes, he does watch...no they don't have the greatest communication, but I sent my stuff, I called a week or so later, paid via credit card, and he shipped them back with tracking #'s and everything sounds amazing....so... discredit to alot of stuff sure, but one thing is he made me happy...

Now I just wait for my new serial # plates

Good to hear-so if he is still watching-come on Rico get some "new" AMT3's out.
I am working on and off on my Super AMT3's, and think I have finally come upon the right combination of ( modern) drivers and modifications (probably including some minor fine tuning to the crossover)-to move these up a level or two over stock- believe it or not. I could say "stumbled", but it's been alot of work- and cost of course, but that doesn't really bother me. With twin 3.5 year old girls, time is what is scarce. From my initial testing-these Super's should clearly rock, and be a audible improvement in extension and efficiency over the stock units. Yes-they will sound different, they will lose the mellow fast Alnico bass-but will offer less bass distortion, and still keep up nicely with the Heil. Porbably more analytical in this frequency range (transition/midbass as well-although the stock woofers will point out a weak amp pretty quick)-so it would be a matter of taste in many respects.
I'm not going to elaborate on these for the time being, but I will being starting up a new Super AMT3 thread when I get them done, and do some final testing, and get the equipment over hear to do some sweeps and document some measurments etc. I wanted to take them over to Electrovoice, but my nephew isn't working there anymore-I took to long with my swaping and experiementing-but that's fine, I can improvise.
I will also post cabinet internal specs/midtube specs, damping material type/amount etc to make a quicker data base.
Fr my crossovers, I have basically been using a spare set of AMT3's PC boards I came across, and installed some disconnects to, to enable easy swapping, but will post a hard wired version layout for a review first before my final assy to make sure I haven't missed anything. I want this set hardwired.
If ESs was to do the AMT3 again-they could always go the Silent Speaker route and build them for each order. You could have to do some gambling on drivers purchases (cabs as well)-to get the pricing etc, but personally I would set the purchase price of the speakers and profit margin to reflect the highest cost of materials you would have to pay, on the lowest scale purchase, and go from there. Order as you need them, same with the cabs. A custom AMT3 built to order. Stamp the onwers name on the seriel plate, print out a nice owners document with seriel number, and purchasers name etc, Built to oder, one at a time. A 40% gross profit (not markup-as cost are only part of the business picture) would be ideal, but even a 35% gross profit should be doable if your running a efficient business, that obviously focuses on gross profit not markups. Personally I would source Eminece, as they can build you anything you want. Misco as well. Sure the cost is more-but you pass these on to the customer. Don't be afraid to charge for a quality product, but on the other hand keep your profit margin at realisitc levels.
If you can't run your business (pay your self, employess living wages and have enough for additional/future capital investments as well at a 35% to 40% gross profit margin, your running a highly inefficienet business-and you need to tackle those problems as it will eventually bite you.
IMHO the modern AMT3 would be the model to focus on, your flag ship, while the AMT would be your "classic" model, and perhaps a bool shelf model. Not to sure on the "center channel" model.
Personally I would run a twin 8" woofer speaker-like a DLK 1 1/2, and run a smaller Heil in a D' Appolito configuration, and just turn them on the side for a center channel. 3 models would be a good line up, all built to order.
If the 13 plete diaphrams are inferior, go back to the 17 pleat-charge accordingly.
I can imagine, and know some of the current ESS problems-but they are all easily fiixable IMHO, if you focus on a few simple things. The potential is clearly there-no doubt. Truely believing in this potential may be one of the biggest problems the current ESS company has-looking at some of the things El Seven, for example, has mentioned. These "problems" (difficulties) wouldn't be problems-just something that has been, or will be addressed in the proper timely manner. Par for the course in any business. Belief and focus makes these minor bumps, and future problems just that-bumps. Belief and focus makes you run a efficient business focused on gross profit. Beleif and focus keeps you from spending your profits on a weekend in 'Vegas, instead of paying your employess, or re- investing in your company-etc, etc.
People want to buy from a succesful company, business or person-not one teetering on the edge.
Having a superior product, such as the Heil AMT, it really shouldn't be that difficult to run a succesfull ESS speaker company if your focused and realistc (honest is a better word) with yourself, your goals and your products. Again IMHO there is clearly potential for money to be made-no doubt in my mind.
Running a succesful business isn't really that hard or difficult if your have the right tools and focus, and belive in what your doing. Aside from having access to initial capital, this is the biggest pitfall I see with others in my own business to overcome. I understand, and really don't understand why this is. It requires alot of work and energy-but those are 2 totally different things. Perhaps it's just a human nature thing, procrastination, lazy, lack of life focus.
Those who claim it's difficult really do so by their own choosing. If it's that hard for you, you are probably better off working for someone else. Same goes for any job-lifes too short to toil all day long and not really enjoy what your doing.
I have been running my own business for 17 years, sure I have had problems, but they all have been minor when I look back on them. Having focus and belief keeps those from magifying, and becoming a weight. Keeps you in control of your business destiny. And that's the real reason I got in to my own business myself- not to nessisarily get "rich", but to control my current and future financial destiny-plain and simple.
It's really like driving a car and avoiding accidents. Having lots' of speeding and violations, DWI's etc makes those occasional "accidents" bigger then they should be, in terms of cost's and emmotional grief etc. You have little to fall back on in the temporary. Really not that big of deal if your honest with yourself. Same goes for the personal-but I will avoid that one.

 

[decooney]

I spoke with Rick more than a few times over the past few months. It took several calls back and forth, but he was able to send me some old crossover parts that I wanted to evaluate as a baseline. They finally did send them out, and to be honest, I was surprised - he did send them quickly after I ordered them. Again, old stuff, nothing new but regardless - I did get them. It might be wishful thinking but I for one hope they try to focus on ramping up quality on parts, working to develop a great sounding and nice looking line of speakers again. I remember the days when it was a privilege in the 70s & 80s just to have a nice ESS brochure in your hands let alone a set of AMT speakers.

My Project:
I'm hoping to try something I've wanted to do for a long time. Working on putting together pieces for DIY Heil project myself, using twin 8s per speaker with an older pair of AMT 1C Heils. Just ordered four new 8" HDS Nomex Peerless woofers.

After months of reading about all the different woofer ideas and options, I decided to do something just a bit different than the norm of going with a 2-way 10" or 12" setup and a Heil. Hoping it will work. Might take a few iterations of crossovers or changes but I'm willing to give it a try and see.

This will be an MTM configuration, with an open front & back for the Heil (sides partially blocked off), and each mid-woofer in it's own chamber. Right after I ordered the woofers, found a guy who did something very similar here in AK back in 2007 but open baffle. He never commented on how it actually sounded. For cabinets, hoping to make some basic HDF test mules just to get started. If it sounds decent, I hope to finish the cabinets off later or make nice new ones with pretty wood sides, something like the old AMTs had just for my own nostalgia reasons - maybe more so just out of respect for old ESS days.

Being a mildly experienced hobbyist with scratch type speaker building, I've probably failed more than succeeded at truly mastering any build - always looking for something more I'm expecting to have some hard learned lessons and failures before I can truly expect for my latest attempt to be good, or anything close to what some of you AMT Heilaphiles here on AK have already tried or done so far in your own DIY Heil projects. Will give it a go though through the upcoming summer. We'll see.

 

[automojo]

At least with the larger 10" to 12" woofers, you really need highly efficient woofers that have above average transient response. I would say the same for smaller woofers. This is the area were a lot of people stumble, as the woofers that work best are close to pro-sound woofers, just with a more extended lower response-which usally lowers the upper response as well.
Anything under 90 db probalby will have some integration problems.

 

[DRMcD]

I've been watching these ESS threads with interest.

:thmbsp:

Sorry for any confusion, DRMcD asked if the owner watched anything in these threads and by owner i thought, he meant owner.

I kinda meant to do that

Working on putting together pieces for DIY Heil project myself, using twin 8s per speaker with an older pair of AMT 1C Heils.

Wow... I hope you can document this. I'm chewin on ideas for my speakers (see sig link), and the amp to drive them won't be ready til after October.

At least with the larger 10" to 12" woofers, you really need highly efficient woofers that have above average transient response. I would say the same for smaller woofers. This is the area were a lot of people stumble, as the woofers that work best are close to pro-sound woofers, just with a more extended lower response-which usally lowers the upper response as well.
Anything under 90 db probalby will have some integration problems.

Slow guy question: lighter cone/suspension = faster response? So no poly or rubber?



[spends Friday night woofer shoppin again]

 

[decooney]

At least with the larger 10" to 12" woofers, you really need highly efficient woofers that have above average transient response. I would say the same for smaller woofers. This is the area were a lot of people stumble, as the woofers that work best are close to pro-sound woofers, just with a more extended lower response-which usally lowers the upper response as well. Anything under 90 db probalby will have some integration problems.

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The pair of 8" woofers I'm planning to use for each speaker measure 89.7 to 90.2 db per unit, according to multiple sources. Running Two of these woofers per speaker adds about +3db. And, running them in parallel down from 8ohm to 4ohm adds another +3db of gain so I'm told. If this is true, 95-96db should be plenty mid-woofer output to keep up with the Heil. In fact, probably too much. I'm thinking I may have to choke down on the woofers or max out the "presence" knob (l-pad) for the Heil on the factory ESS AMT Monitor crossover I'm starting off with just for grins for the first version. For revision 2, I'm expecting to have to make or purchase new crossovers, and if I do, I'll probably go up to 1600hz crossover point, but wanna hear it at 1000hz first with the factory ESS crossovers just to see how far off it is and how it will sound. Its all in theory and a guess at this point for me. We'll see... just an idea to try. Have always wanted to try the large heil paired up against a pair of paper 8s, and in this case I'll be using Nomex HDS woofers, close enough I hope.

 

[automojo]

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The pair of 8" woofers I'm planning to use for each speaker measure 89.7 to 90.2 db per unit, according to multiple sources. Running Two of these woofers per speaker adds about +3db. And, running them in parallel down from 8ohm to 4ohm adds another +3db of gain so I'm told. If this is true, 95-96db should be plenty mid-woofer output to keep up with the Heil. In fact, probably too much. I'm thinking I may have to choke down on the woofers or max out the "presence" knob (l-pad) for the Heil on the factory ESS AMT Monitor crossover I'm starting off with just for grins for the first version. For revision 2, I'm expecting to have to make or purchase new crossovers, and if I do, I'll probably go up to 1600hz crossover point, but wanna hear it at 1000hz first with the factory ESS crossovers just to see how far off it is and how it will sound. Its all in theory and a guess at this point for me. We'll see... just an idea to try. Have always wanted to try the large heil paired up against a pair of paper 8s, and in this case I'll be using Nomex HDS woofers, close enough I hope.

No-that output should be fine, the output in the lower regieons will obviously be lower but this of course is normal, as this is a average. You could alwways Zobel it, which drops some output, but I woudln't "pad" the woofers as you are just wasting power and losing efficiency.
I don't think the cone material really matters per say- paper is better, but the Audax HM 130CO carbon fiber midwoofer, for example works well as a AMT3 transistion driver and is highly efficient. Most poly woofers are "slow", but I'm sure there are exceptions as well.
What you really want is highly efficient drivers that do have a resonant peak out of their normal passband, and smooth roll offs. You can correct this with filters, but this isn't really the ideal solution. This drivers are hard to find in the modern lineup.
Having said that, I'm sure the Peerless woofer will work well with the correct crossover mods-smaller drivers are easier to work with with the Heil, especially using 2 woofer improves the integration and bass output-that in part, along with the transition driver is why the AMT3 design works so well.
2 key elements-(1) twin "smallish" woofers and (2) transition driver, really solves all the problems people run into with DIY Heil designs.
If the Peerless has a box makeup for this driver, I would look at it closely. P.E.-if they carry this driver can help you out with their software. Madisound also had a free speaker designer that is helpful.

 

[decooney]

Thanks Auto.

Yeah... shooting for 43hz and keeping it as flat as possible I've modeled the enclosure about five different times already myself with different online tools, and through others who own software. I did get input from PE, Madisound, and Timphany using at least three different software programs with different engineers trying it and comparing to make sure. What is strange is lack of consistency across any of these software programs. Most show the enclosure volume per woofer to be within .27 cu ft of each other but the tuned port recommendations vary quite a bit from once source program to another. Its all over the place... the variance is so great I won't do the ports or start on cabinets until I can be a bit more certain.

It would be helpful to find someone who has one of the better (known best) software packages and have them run the figures for me and see what they come up with. Can't start on cabinets until then.

 

[automojo]

Don't feel bad, I ran into the same things with my AMT3's when dealing with non stock woofers. That's really the problem with ported enclosures, the specs or data says one thing, real world listening says another.
But the big part of that is room response, in part why measurments below 200hz aren't very accurate. The other part is the cabinet of course.
I was breifly toying with moding my DLK 1 1/'2 with a smaller Heil, and using 4 of the Dayton ST210-8's, although the stock DLK woofers are pretty good, but I'm not sure if they could keep up with the Heil-mine are the older Alnico green baskets types. If I recall the size of the port kinda ruled them out, although they are a jack of all trades woofer, and can worked sealed at the expense of lower response.
I did end up modding them with a Audax "vintage" dome tweeter, which made a huge difference, and the highs now keep up with the woofers. At $28 this tweeter is a excellent upgrade to any cone driver in a 2-way that needs to go down to around 1000hz.
But they aren't AMT3 my any means, or a ESS Heil, good in their own right with a nice fairly uncolored reponse.

 

[decooney]

Got the dual 8" woofers selected now and purchased, and was able to get an engineer to confirm the volume requirements for the woofers, along with the tuned port.

Still having a bit of an issue confirming the db efficiency of the older Heil tweeter used on the AMT Monitors and 1Cs. I've seen 90.5db, 91db, and even 96db written by different people. For some reason, I always thought it was about 91db or so.

Does anyone here know for sure what the older Heil db output was based on real tests conducted you've conducted yourself?

 

[el seven]

Got the dual 8" woofers selected now and purchased, and was able to get an engineer to confirm the volume requirements for the woofers, along with the tuned port.

Still having a bit of an issue confirming the db efficiency of the older Heil tweeter used on the AMT Monitors and 1Cs. I've seen 90.5db, 91db, and even 96db written by different people. For some reason, I always thought it was about 91db or so.

Does anyone here know for sure what the older Heil db output was based on real tests conducted you've conducted yourself?

Herman ran tests and faxed them over, showing 91.9 on the German assembled membranes and if i recall correctly they were 1.1db over and above the current units. Should you want the original results from the 80's you're probably out of luck there. 96 is way out of line, they've never measured that high that i've ever seen.

Good news on those woofers, i guess you can start in on those cabinets now?

 

[decooney]

Hey El,

That's good to know. I have the 1C Heils, so I suspect 91db is more likely. I too never heard of much more than a +/- 1db variance over the past few decades on everything I've seen written about the large Heils either so that seems more consistent. Yeah, I think some experimental mule cabinets are next. Checked out the woofers today, they look pretty good, seem to be well constructed so I'll keep them and go for it in a few weeks. I did have a chance to meet someone very experienced who has been down this path before with the Heils in different configurations. This is not my first Heil project, but I have a feeling it will be my last. As I figured going into it, there are other factors in play with doing this custom Heil build that are above my head and my experience - well beyond the original AMT Monitor or other AMT cabinet designs. Simply copying the older designs with dual 8s is just not something I'm going to do successfully with ease, if at all very well in the end, but I still want to do it. The big hang-up is the crossover for sure. Simply using some original AMT Monitor crossovers seems feasible at first until I started talking with some folks who really know a lot more than I ever will.

There are some really good threads on this site and DIYaudio from back in 2006 and 2007 where folks were doing some neat things with Heils, all sorts of different configurations, different size and quantity of woofers, hornloading, multiple Heils and more. People have done some pretty cool, fun, and interesthing things out there. Every time I think I've seen the last thread on a custom Heil project, I find another one I'd never seen before.

The little Heil membrane that could sure has kept people curious for a long time and still going. Looking around the past few months, I can't believe how many new speakers are out there now that leverage the Heil membrane or Heil ribbon (concepts) as we know it here.

 

[puppet]

http://www.hifisound.de/oxid/out/oxbaseshop/html/0/test_pdf/ESS-1013915.pdf

So, who did these tests?

 

[djnagle]

Not sure who did that test, but I do know that there should not be an impedance spike that large at 1K. I've run the 2 pairs I had and have (old style aluminum face) thru a couple differnt testers and there is a little bump at 1K but not anything as large as what is on the graph. the rest of the data looks good though.

 

[automojo]

Yes-I saw this same graph brought up a year or so ago were the poster used this as his reason for his dislike of AMT Heils.
One has to look at the parimeters of the test/measurments.
Also one has to take into account near field vs room response, especially when talking about a dipole driver.
This 1975 review of the ESS AMT3 seems to confirm what I have heard in listening with my 2 pairs of AMT3's, more or less-as you take your room acoustics into account.
http://www.audiokarma.org/forums/attachment.php?attachmentid=270486&d=1303424059
http://www.audiokarma.org/forums/attachment.php?attachmentid=270487&d=1303424059
I'm looking foward to your project for one, I hope your start a seperate thread on this. Hopefully those woofers work out well.
I'm am also finalizing my final version of my "Super AMT3's", with non stock woofers and midwoofer, so perhaps these projects will kind of parallel each other.
I have gone through more then a few woofers, and midwoofers, and I finally stumbled into the right combination, and centered on the right combination of port size and tuning. I have also done some more cabinet mods to reduce rear panel vibrations.
My test mule sounds incredible in tests so far, and is no doubt a step above the stock AMT3 configuration, and plays much cleaner at higher volumes-as well at lower ones as well. And a step up in midbass/lower midrange clarity.
This has been a very difficult search-matching woofers/midwoofers the limits of a stock cabinet configuration, and making a real improvement-as testiment to the original AMT3 design.
Look foward to your upcoming project-please keep us posted!:thmbsp:

 

[djnagle]

This is the second pair of Heils I've worked with and the one thing (out of many) that astounds me is that they are much more effiencent than stated. My JBL E140 woofers are 100db and I have to pad down the Heils 9db to match them. I know that I am loosing some eff. on the woofers using it is a sealed box, but still......

I am using mine with a 4uf oil/can motor run cap so it is a 1st order roll off starting at 10k and they really integrate seamlessly with my 350hz Edgarhorns.

 

[djnagle]

I just went back to the page in German and was surprised to see that they have the eff at 100db. That matches my finding better than the U.S. sales lit.

 

[decooney]

http://www.hifisound.de/oxid/out/oxbaseshop/html/0/test_pdf/ESS-1013915.pdf

So, who did these tests?

Not sure, but interesting "efficiency data" as it shows. The first data spec shows 100db at 4K HZ at the top, then reads 90db at 1khz below, and another spec below that states 110db but does not clearly state at what frequency. I have the older Heils just like this from 1Cs or AMT monitors. I will know when I hook up the woofers and heil.

Still struggling with the right cabinet design. I started with MTM, abandoned it, and right back to MTM again with dual 8s. I've been advised by more than a few to avoid closing the sides like my AMT Monitors had, and possibly creating a baffle for the Heil. I may do something in between. The more I look at this, the more I'm sure I need some rough test cabinets to start with. What's interesting about this project is just how many different firm ideas there are from different hobbyists about what should or should not be in and around the Heil itself.

 

[el seven]

Those results are from Frankfurt when Herman Hoffman was under Leo David. Note that the polyamid(e) diaphragm is under load. He proposed this membrane substrate with those results in tow but i assume the mfg costs were too high at the time (Germany).

The sensitivity specs are also subject to falsification (as a distinctly common marketing practice in loudspeaker testing by mfgr's) or should i actually say; misrepresented math. At an 8ohm load 2.83v will give you 1w but at 3.4ohms you're seeing > 2w output. So far as to assume the test environment was indeed proprietary to bending the rules in favor of dbspl i can only suggest, but cannot confirm it.

Take 2w output @ 1m into 3.4ohms, the then-folded polyamide membrane, and the unknown environment into consideration, coupled with known 2w/1m parameters and, voila. Funny that when he sent over the graphs on the teflon diaphragm they came in at much more respectable and believable levels of output. Leaving out the character that Herman is... i would easily suspect it's more reliable math to draw 6~7db back from those published.

decooney, i suggest you run it wild initially and bar anything from obstructing dispersion in your mule if you possibly can. Are you able to produce any prototype cabs (albeit ugly ones lol) at all... from home? Setting up the amt on-axis 3rd order butterworth is rather keen really. The xovers you now have (hang on i will look 'em up) should be fine for a minute.

 

[el seven]

Schematics i have from the am Monitor are 3 total, as in of late 78 / thru 79 / early 80 with the 1980 unit being the most complex - using 4 resistors in a split zobel and full zobel, as well as 3 caps and 3 coils. Let me know what layout you have duane and i'll provide rolloff freq's.

 

[puppet]

T

The sensitivity specs are also subject to falsification (as a distinctly common marketing practice in loudspeaker testing by mfgr's) or should i actually say; misrepresented math. At an 8ohm load 2.83v will give you 1w but at 3.4ohms you're seeing > 2w output. So far as to assume the test environment was indeed proprietary to bending the rules in favor of dbspl i can only suggest, but cannot confirm it.

Take 2w output @ 1m into 3.4ohms, the then-folded polyamide membrane, and the unknown environment into consideration, coupled with known 2w/1m parameters and, voila. Funny that when he sent over the graphs on the teflon diaphragm they came in at much more respectable and believable levels of output. Leaving out the character that Herman is... i would easily suspect it's more reliable math to draw 6~7db back from those published.

The sensitivity baseline would account for approx. 3db, if I remember right.(apples to apples) ... the diaphragm differences I'd have no idea (lacking both examples).

What I do know is that my experiences with the heil sort of mimics what djnagle has found. My woofer is around 92db eff. My AXO has input level meters and it's able to adjust db levels to match output signal. It takes 3-4db of boost to align the output of the woofer to the heils. (this is taking the human ear out of the equation).

While 100db is not a real level, considering the 8-4ohm factoring ... it is definitely hovering around 94-95db IME here (with the newer versions of diaphragm).

As an aside, I've seen Nelson Pass mention that the heil actually performs as a 6ohm driver.**(load presented to the amplifier) So, perhaps a straight 3db reduction in the sensitivity figures is not appropriate either.