Best XO for the ESS Heil AMT

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Hi I am building an OB with a dipole-15 and some not chosen 6" driver and the ESS AMT

So I guess that I am looking for a great bas / midrange driver, 250hz and up to 3 maybe 5khz.

Candidates could be:

  • Tang Band W8-1808
  • 18Sound 6ND430-8

There is also this excellent link

But I need a fast driver with a minimum sensitivity of 93db

Any suggestions? gents and ladys (-:
 
I use the Heil AMT down to 750Hz and think it sounds great. Not thin at all. I use B&C 6MDN44 for mid from 200Hz to 750Hz with LR4 XO. I have a bass horn handling 30Hz to 200Hz. I try to XO as low as possible so that the AMT serves almost like a point source phase coherent full range driver for excellent imaging. The Heils are special - nothing else can sound this detailed and dynamic with no breakup in the highs.
 
After playing around for sometime, we XOed the Heil at 2 kHz.

heil-fostex.jpg


dave
 
I built a couple of bespoke enclosures a dozen or so years ago with the Heil AMT, and crossed them over a bit higher than xrks'- one was actually a conversion of AMT1 to a 3-way, with Eminence 6" midrange, and XOs of approx 300 and 3K IIRC.


The other was with back to back Fostex FW187 woofers (long discontinued, but very nice unit) - XO was around 2000 as Dave notes above - single cap and no LP on the woofers, as I recall. The 3-way was a bit more complex than that .

The second pair of these made it back into my possession for a while - they sounded wonderful on my tube amps at the time of up to 30watts, but the dipole dispersion pattern is one that just doesn't "work" in my domestic situation.

The factory XO for the original AMT1 was 600Hz, I think - so anywhere from there on up should be fine. It'd be a shame to waste what it does so well by crossing over too high - the funnest part of working with them is getting bass that is both sensitive and "fast" 😀 enough to blend seamlessly. Active bi-amping can solve the first part of that easily enough.

Expense aside, can you imagine what a line array of say 10 of these could do?


I'm gonna get slammed for the "fast bass" comment, but I think y'all know what I mean - not all bass is created equal.
 

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Thanks to all of you - VERY different opinions about this driver and lot of emotions (-:
Are you all using the original Heil? I am a little worried about the rapid roll off at 10khz, is it a problem? and what about Heil AMT II that can go to 30khz

I think I will stick to 6" driver to get good of axis respons and experiment with a XO between 2 and 3 khz.

Any quirks I should know about when building the filter for the heil?
 
A mix of passiv and active

Hello Martin
Are you planning to go passive or active?
The TB 1808 would be a waste since you're have the ESS AMT. In fact, you could probably cross the ESS really low (800-1200 hz). My suggestion for midrange would be the Jantzen JA 8008. 95 db sensitivity and a nice controlled rollof. Will work up to 2 500 hz if you choose to cross higher.
JA-8008 HMQ - Jantzen 8 inch High-Efficiency Speaker - Europe Audio

I will try a mix of passiv and active, using a plate amplifier for the dipole 15 and passiv for the mid bass and the heil AMT
 
Not to pick nits, but this is where I got that number from, and stopped looking ESS amt1

Of course, judging from posted price in yen, and the choppy translation from the original Japanese, perhaps the posted numbers are wrong - or maybe they represent an optimistic target by the design team. I never did hear the original with ported woofers.

Yes, the current specified operating range is 800Hz -20K

The Original Great ESS Heil Air-Motion Transformer |


and, yes, this is still the "best" (hate to use that word) tweeter I've ever heard or built with - I'm not sure that any of the current "budget AMT"s produced by others achieve the same level of performance.

To settle my curiosity after having being "ripped a new one " by positing this years ago in another venue - a couple of questions for the more knowledgeable here:

- does the full on AMT Great Heil driver - as distinguished from sealed back monopole - qualify as a variant of dipole / ribbon?
- how much wave-guide action would the symmetrical stacked magnetic circuit lamination be contributing when operating at the lower end of its capable bandwidth?

amt1.JPG


http://audio-database.com/ESS/speaker/amt1-e.html
 
and, yes, this is still the "best" (hate to use that word) tweeter I've ever heard or built with - I'm not sure that any of the current "budget AMT"s produced by others achieve the same level of performance.

+1 the best tweeter I have ever heard that is almost a full range.The pleated diaphragm area when unfolded is equivalent to a 8in driver, yet weigh nothing. When listening to a female vocal, pick up the Heil and look at it, and you would swear that the singer has been miniaturized and stuck inside the magnet assembly as a prisoner and singing away. It's kind of creepy but that tells you how realistic the sound is.

I think the V waveguide may have something to do with the lower freq operation and the smooth and uniform polars too.
 
I will order a set of AMT today

+1 the best tweeter I have ever heard that is almost a full range.The pleated diaphragm area when unfolded is equivalent to a 8in driver, yet weigh nothing. When listening to a female vocal, pick up the Heil and look at it, and you would swear that the singer has been miniaturized and stuck inside the magnet assembly as a prisoner and singing away. It's kind of creepy but that tells you how realistic the sound is.

I think the V waveguide may have something to do with the lower freq operation and the smooth and uniform polars too.

If I buy them, then there is no way back (-: And there are on sale The Original Great ESS Heil Air-Motion Transformer |.
Now I just need "something" that can play in an OB from 250 to 2khz
 
Did you find the MIDRANGE?

Hi

Did you find the midrange you looked for?

I am building a pair off OB speakers with AMT and 2 x 12" wavecor, I plan on using the Scan Speak 18W discovery bas or mid duties.

Almost done with it.

I have Hypex 2.100 DSP amp for mid, high and filtering, I might be using my DOXA 70 for bas.

best regards

Uwe
 
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