I thought I was already going overboard with two.... If money was no object I would order 15 pairs for a hole line array 😁
Why not using the Mundorf AMT then to replace the ESS AMT completely? The ESS were built over a very long period of time and the problem is, they changed the diaphragm very often and without any notice. If one is broken, you get a new membrane unit from ESS and - surprise, surprise - it sounds a lot different because it's not the same! That's why you buy them used only with the seal still on the diaphragm slots and only in pairs.I've had this happening 3 times and I'm really fed up with it, that's why I bought a used pair then despite having several already laying around.
Don't misunderstand me there, if they work and you've got a pair from the same period, they are amazing! I just wouldn't buy them anymore but back then there were no other air motion transformers than the ESS.
simple EQ would do and you spare extra tweeters. Just pop up the highest octave
I just tested a/b tested whole load of tweeters out of my collection with the heils. All improved the sound over only the Heil. A brandless titanium automotive bullet tweeter did better than softdome and softdome with horn. But I almost don't dare say it....a cheap 2 dollar piezo tweeter marketed for attracting nesting swallows (for bird nest soup) was clearly best. I know piezos have a bad name but I think as pure super tweeters they can be really good. If using them any lower than 6khz they are awful and crossing above 8 or 10khz is probably best.
The piezo adds spaciousness and realism without standing out. I guess it can keep up in speed with the heil membrane but that is pure speculation on my side. But it just sounds more "right" than the other tweeters. I also wanted to test a small GRS amt dipole I know I have somewhere but couldn't find it....
The piezo adds spaciousness and realism without standing out. I guess it can keep up in speed with the heil membrane but that is pure speculation on my side. But it just sounds more "right" than the other tweeters. I also wanted to test a small GRS amt dipole I know I have somewhere but couldn't find it....
Then you want to add dipole woofer arrays, etc, etc and end up with a speaker company like Arion!!
I was showing an older gentleman how tone generator apps work the other day and was surprised to see he couldn't hear ANYTHING when I played a reasonably low 10kHz tone!
I don't perceive a need to boost up the very high treble on stacked Heil's (say >13-14 kHz), but I do have a PEQ I engage only when I run into especially dull recordings, but that "wet sparkle" frequency is actually more around 12kHz and only a couple of dB's.
Those Mundorf diple AMT's are nice, and I like the sound of them as used in Qualio IQ speakers.
https://www.madisoundspeakerstore.com/mundorf-amt17d2.2-dipole-air-motion-tweeter-amt/
However, they are currently $352 EACH(!) and are only 90 dB sensitive/4 Ohms.
I hope people are aware ESS is having a sale again on HEIL AMT's (including mounting accessory) for $250/PAIR currently! Stacked (serial) pair runs ~99 dB sensitive, so if I wanted to add sensitive Piezo tweeters, what are some good ones?
I didn't mean the AMT 17D2.2. Mundorf seems to have purged a lot of AMT models from their program, esp the large (long) units without a face plate or back chamber, which makes them dipoles. What comes closest is the 197PP27F2 which is a 8" high tweeter with 103dB. However, it needs equalizing, modifying the back chamber and is even more expensive (600€). I'm not really fond of this one but since they don't have the older ones anymore, that would be probably the only one from them for this use.
I prefer the Beyma over the Mundorf. The Beyma TPL-150 Air Motion Transformer and Beyma TPL-200 are excellent and interesting for this application too if you're willing to modify/remove the back chamber.
The Monacor MPT-165 sound very good and have a sensitivity of 93dB. I got some of them here, the magazin "Hobby Hifi" used them in the "Micro PA" speaker series (bunch of variants of essentially the same speaker, scaled up and down). They used it from 4kHz up.
If you want to use a horn, the MPT-142 are nice, they got the screw-on mount. Got some of these here too. 93dB and there are tons of horns you can use them with.
If you need more sensitivity, the MPT-177 got 99dB but I haven't heard them yet.
They are still piezos though, not the most linear drivers but as super tweeters that doesn't matter much there anyway and they are cheaper than anything else, so it's worth a try. Don't forget to filter them.
Alternatives are Goldwood, most of which are identical to the Monacor, just labeled different. Don't substitute them with similar looking models from eBay, Ali, etc, I bought some of these and oh boy, are these bad.
Monacors are hard to come by here in the States it seems..
Well, let me add the third AMT in the stack and see what happens.
I do have Beyma TPL150H sitting here, but I find adding that horn added a bit too much of a peak 2-5kHz and preferred it without the horn.
At some point, I do have to figure out how to devise an open back solution for Beyma..
Well, let me add the third AMT in the stack and see what happens.
I do have Beyma TPL150H sitting here, but I find adding that horn added a bit too much of a peak 2-5kHz and preferred it without the horn.
At some point, I do have to figure out how to devise an open back solution for Beyma..
There is a design for a small DIY dipole AMT tweeter that is very easy to build in this thread: https://www.diyaudio.com/community/threads/amt-for-line-array.413465/. There is a bit more info on this tweeter in the latest blog on the audiodevelopers.com website. That design is actually a cluster of 4 individual tweeters, but you can modify the design to use just a single diaphragm.
I bought a whole load of piezo tweeters online just to play with. Most were really harsh and grating to the ears. When opening them they mostly looked like they were assembled by monkeys. (Stuff not consistent, not centered, random dollops of glue)
The only one that looked and sounded good to me was from a Malaysian company called Audax (I doubt they have anything to do with the famous Audax tweeter company) They purely make them to entice birds into bird nest farming towers. My particular model is the AX-21 (94dB and goes up to 23Khz)
There are several Malaysian manufacturers claiming their tweeters attract the most birds. They are all horn tweeters with either piezo or magnet/titanum.
I guess if it can fool birds ears it can fool mine too.
These swiftlets farms are all over South East Asia.
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And magically its horn has nearly the same width as the Heil. And if you put two of them back to back they are exactly the same depth as well.
Malasia?! Audax AX-21 piezo's not to be found anywhere in U.S.
I prefer not to go crazy and throw $$ at things like Fostex T90A, T500A, etc. A nice used pair of Fane ST5022 would be nice but hard to come by.
Anyone tried something like Skar Audio bullet tweeters?
https://www.skaraudio.com/products/vx1-st-1-inch-pro-audio-tweeters
I prefer not to go crazy and throw $$ at things like Fostex T90A, T500A, etc. A nice used pair of Fane ST5022 would be nice but hard to come by.
Anyone tried something like Skar Audio bullet tweeters?
https://www.skaraudio.com/products/vx1-st-1-inch-pro-audio-tweeters