Newby ?? ESS AMT 2

[btacroft1]

Looking to build a speaker system around a set of ESS AMT 2 tweeters .
Need Real nice Boxes ,woofers ,crossovers . What can you YOU Recomend.? 2 way set up ,Just trying to get ideas.
ALEX2507 sent me.

 

[Alex2507]

Looking to build a speaker system around a set of ESS AMT 2 tweeters .
Need Real nice Boxes ,woofers ,crossovers . What can you YOU Recomend.? 2 way set up ,Just trying to get ideas.
ALEX2507 sent me.

This is them just to use as a reference:

btacroft1 made the distinction of owning the newer silver colored ones as opposed to the older black ones pictured here.
He only has a pair.

After doing a quick search I didn't come across any readily available designs nor was I able to find the T/S Parameters if that even applies to these things.

I thought Swerd, TLS or WmAx may have some ideas on where to get info and maybe some direction for these tweeters. Would a Dayton Woofer Tester 3 work with these to establish the T/S parameters? My friend would love to buy one that I could use pretty much any time I need to ... well, he didn't come out and say so but I could tell that he was thinking it.

 

[btacroft1]

????????

Must be a nother friend

 

[Rickster71]

Looking to build a speaker system around a set of ESS AMT 2 tweeters .
Need Real nice Boxes ,woofers ,crossovers . What can you YOU Recomend.? 2 way set up ,Just trying to get ideas.
ALEX2507 sent me.

Those ESS AMT's are nice. Though I would have to question your judgment, as to your association with this Alex2507 character.

Those are not cheap; saw them on fleabay for $450 a pair.
A bit of info:
Sensitivity of 95 dB in conjunction with wide frequency range from 2.5 kHz to 30 kHz. Resonance frequency is at 1.4 kHz, DC resistance is 4.1 Ohm,

 

[Swerd]

I confess to knowing nothing about those ESS tweeters, and I wouldn't risk using a Woofer Tester on them.

You might learn something useful by asking at the Parts Express Tech Talk forum.

A quick search at Madisound I found that Eton now sells something called an "Air Motion Tweeter", but I don't know if they are similar to what your friend has.

I also found this by google search
http://www.lautsprechershop.de/hifi/index_en.htm?/hifi/baendchen_en.htm

 

[Alex2507]

Must be a nother friend

Eddie wants to buy that for me?
That's fantastic!

Those are not cheap; saw them on fleabay for $450 a pair.

Yeah, he got 'em on fleabay for way less. How would you go about safely testing these? I have a Rives Audio Test CD 2 but I'm pretty sure that you would want to hook up a capacitor to protect the tweeters.

I got that Speaker Building 201 by Ray Alden but I'm still glued to the pictures. I think I read that he only addresses one ribbon tweeter design and this isn't even that.

How would a 1.4KHz resonant frequency act in a speaker that had a FR above 2.5KHz?

 

[Rickster71]

Yeah, he got 'em on fleabay for way less. How would you go about safely testing these? I have a Rives Audio Test CD 2 but I'm pretty sure that you would want to hook up a capacitor to protect the tweeters.

I got that Speaker Building 201 by Ray Alden but I'm still glued to the pictures. I think I read that he only addresses one ribbon tweeter design and this isn't even that.

How would a 1.4KHz resonant frequency act in a speaker that had a FR above 2.5KHz?

I say we wait for one of the professionals.

 

[Swerd]

How would a 1.4KHz resonant frequency act in a speaker that had a FR above 2.5KHz?

A rough rule of thumb for tweeters (at least for more standard dome tweeters that have a voice coil and dome) is to cross them over no lower than about double the resonant frequency (Fs). For 1.4 kHz, that would be 2.8 kHz. The maker claims a frequency response of 2.5 to 30 kHz, so that seems about right. I assume that means a "useable" frequency response. Without knowing more about the tweeter, it might be better to cross it at about 3 kHz.

I checked Zaph Audio, but he has not tested this tweet.

Its probably more important to measure what a tweeter can do by running a freq sweep once it is mounted in its cabinet. The cabinet width and mounting location on the front baffle have a noticeable effect on a tweeter's sound, so don't spend a lot of time doing measurements without a cabinet.

 

[Alex2507]

... so don't spend a lot of time doing measurements without a cabinet.

I meant that I wanted to test the tweeters just to make sure that they were operational and not eBay junk. Should they prove to be defective ... well, we can move right past this craziness and go back to listening to me sing on Saturday evenings.

Your link takes me to that site where I can't find the specific driver with the info that Rick posted which may be the 2nd one down here if this link works any better.

Wikipedia had this info. This is pretty exciting when I consider the cost of the tweeters. Could the sound actually be all that? I might actually get to hear these things without having to lift a finger.

 

[annunaki]

If the Fs is indeed 1.4khz, I would crossover no lower than 2.8Khz-3Khz with a 2nd order filter.

Finding a good woofer with acceptable use that high is the next challenge.

 

[Alex2507]

Without knowing more about the tweeter, it might be better to cross it at about 3 kHz..

If the Fs is indeed 1.4khz, I would crossover no lower than 2.8Khz-3Khz with a 2nd order filter.

That looks like a consensus and the 2nd piece to the puzzle with the recommendation of a 12db/octave crossover slope.

Finding a good woofer with acceptable use that high is the next challenge.

The 4" Infinity Primus driver used in the P142/140 get's crossed at 3KHz with a 4th order slope.

They are only good down to 100Hz in the 142 enclosure but what would happen with a bigger box and maybe doubling up on the 4" drivers? I actually have 4 of those drivers and another 2 are hanging on our friend Eddie's walls.

The OP has a couple of unused 6-1/2" Infinity Beta drivers that get x-ed at 2.5KHz in a OWS-1 enclosure.

Can you say Frankenstein ???

 

[Swerd]

That looks like a consensus and the 2nd piece to the puzzle with the recommendation of a 12db/octave crossover slope.

First decide on a woofer before you decide on crossover points or slopes.

The 4" Infinity Primus driver used in the P142/140 get's crossed at 3KHz with a 4th order slope.

They are only good down to 100Hz in the 142 enclosure but what would happen with a bigger box and maybe doubling up on the 4" drivers? I actually have 4 of those drivers and another 2 are hanging on our friend Eddie's walls.

The OP has a couple of unused 6-1/2" Infinity Beta drivers that get x-ed at 2.5KHz in a OWS-1 enclosure.

You ought to be able to find 5" or 5½" woofers that can be crossed at about 2.5-2.6 kHz. The real issue is finding a woofer where the on-axis frequency response curve is very close to the 15° or 30° off-axis curve. You get much better imaging if you set the crossover point with this in mind. Once you know the crossover point, then go find a tweeter that can go that low. Like I said above, look at the tweeter's Fs and double it as a rough estimate if it can go that low. Usually with dome tweeters, the lower the Fs the higher the cost. All bets are off with ribbons or those ESS tweeters until you find a spec sheet from the manufacturer.

For example, the Seas CA15 woofer has on-axis and 30° off-axis curves that are still close together between 2-3 kHz. Notice also how smooth the response is above 3 kHz. Even with a 4th order crossover (24dB/octave) you will hear stuff from the woofer up to an octave above the crossover frequency. With a 2nd order crossover, this becomes more important. So the CA15 would be a real good woofer to use. Another good one is the M-130.

Compare that to the Dayton RS150. The freq response curves look good up to about 2 kHz, but above that the two curves separate, and by 3 kHz things go bad in a hurry. I wouldn't cross this woofer any higher than 2 kHz, and I'd use a 4th order crossover.

See if you can find frequency response curves for those Infinity drivers you mentioned that show on-axis and off-axis curves. Then you can decide if they would be a good match for those ESS tweeters.

 

[TLS Guy]

Looking to build a speaker system around a set of ESS AMT 2 tweeters .
Need Real nice Boxes ,woofers ,crossovers . What can you YOU Recomend.? 2 way set up ,Just trying to get ideas.
ALEX2507 sent me.

This will be a hit and miss project.

I can find no acoustic data for the driver.

Dr Oscar Heil's patents have now expired and so deigns based on his idea are starting to show up form around the globe. With modern materials they my enjoy more success than Dr Heil did with them.

The big problem with the Heils were their unreliability, especially when pushed.

I would cross them over third or fourth order no lower then 2.8 KHz, or you will likely blow them.

What sort of speaker do you have in mind for them, bookshelves or towers?

I would select a driver to match with it, that has a good response to 3 to 4 kHz range with an acoustic second order roll off.

If you used two of these in MTM configuration crossover third order at 3 kHz it probably would do the trick.

 

[WmAx]

You can send me one of those Heil based drivers and I will give you full acoustical response data (including full polar response and distortion data). However, I will not be responsible for damaging the driver; these are known to be relatively fragile and test tones may damage the test unit.

-Chris

 

[Alex2507]

I will not be responsible for damaging the driver ... tones may damage the test unit.

Uh-yeah, I'm sure he'll have it right out to you.

 

[WmAx]

Uh-yeah, I'm sure he'll have it right out to you.

LOL... yeah. But that is a real issue that must be considered ; who knows how sensitive this driver may be? I only offered to test it because it co-incides with my measuring/programming of Jerry's speakers; so the gear is set up and measuring them would not be any kind of inconvenience for me - plus I want to know the off axis response of the tweeters - as they may be something I could use in a future project.

-Chris

 

[Alex2507]

... who knows how sensitive this driver may be?

From the link in post #9:
"This small AMT by the US manufacturer ESS, shows a remarkable sensitivity of 95 dB."

I was just talking to this bta1croft guy (what a handle) and told him that TLS' suggestion was a decent inexpensive start. The box volume would be dictated by the recommended woofers as the tweeter is self contained. The next part for this fished for design would be to get a box volume suggested in the bookshelf size, distances from tweeter to main, port size and lengths for dual ports and an actual crossover design.

I thought that L-pads would be good to be able to have some adjustment on these after the fact. The sensitivity of the tweeters has been linked already but that of course is questionable.

Personally I dislike the whole thing as info isn't readily available. Just a bunch of German guys with their hands out wanting to sell something.

No hurry on any of this though. Even though he has the tweeters, he's had them for years!

 

[WmAx]

From the link in post #9:
"This small AMT by the US manufacturer ESS, shows a remarkable sensitivity of 95 dB."

LOL.... sorry. That is not what I meant. I mean... sensitivity to damage.... as in physical fragility...

-Chris

 

[Alex2507]

LOL.... sorry. That is not what I meant. I mean... sensitivity to damage.... as in physical fragility...

-Chris

Don't worry, Chris. I'll work with you on the speaker lingo. I know you are just starting out and I want you to know that Audioholics is here for the budding designers the whole world over thanks to the www that Al Gore invented.

If you have any other things you need cleared up ... I'm here for ya.

 

[Arthur Tatum]

Aint going to discuss ESS AMTs with a low grade essaphobic primate, who only shows images of the small Heils.
All primates dont have so good high frequency hearing, nuff said, this forum aint helpfull, wont be back soon!