Here's a version I translated to English. I bought a pair a year or so ago and they didn't have the big 7 KHz dip. The Heil AMTs have undergone multiple design changes over the years so the dip may have been fixed.
Really tempted to get a pair while they're on sale. I have a vintage pair in hibernation that I planned to put to use soon. The diaphragms are in rough shape though. Contemplated getting new diaphragms, but at $100 each, it's a no-brainer to pay the $50 more for a complete pair.
I really haven’t heard an AMT on its own I didn’t like yet……to my ears they sound more revealing than soft domes without the strain…..and just as revealing as hard domes without the hard edge. Not quite on the same level as true ribbons but the wider operating bandwidth levels the playing field.
My hope is as time goes on, tech improvements will result in the AMT taking the place of the dome….if they can get the costs more in line that is.
I‘m on the fence on ordering a pair though….just bought a new astrophotography camera and pretty much wiped out my allowance……another package shows up at the door and I’m in big trouble. Lol
My hope is as time goes on, tech improvements will result in the AMT taking the place of the dome….if they can get the costs more in line that is.
I‘m on the fence on ordering a pair though….just bought a new astrophotography camera and pretty much wiped out my allowance……another package shows up at the door and I’m in big trouble. Lol
Can't do that only looked to 40 degrees after that your pointing at the side of the driver, I will post what I measured there is another in a thread @ Lansing Heritage can't get into the site.
Rob
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Just planning out my stacking..
When you stack the AMT-1 with both AMT's in "stock" configuration (ESS label on bottom), there seems to be some magnetic repulsion between the two. Is this how you are supposed to stack them or perhaps flip one upside down?
And can I assume the Purple wire is "+" and light blue wire "-"?
Finally, is it recommended to wire them in parallel or series? I presume series is better since AMT-1 already has low impedance.
Thanks.
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I didn't notice any magnetic repulsion issues. Yes, I stacked them like you show. I suppose you could invert one of them if it bothered you. There's a lot of steel in one of these units (i.e., someone said 14.5 lbs), so the magnetic field around the diaphragm is not materially affected by what's occurring outside of the driver's external envelope.
I would check the polarity of the leads/wire insulation color via REW measurement of phase/SPL.
Since they are 3.2 Ohms minimum impedance, I wired in series. I don't know many amplifiers that could stably drive a 1.1 Ohm minimum impedance if you tried to wire in parallel.
Finally, I stacked them at a 15 degree angle using a bit of neoprene material I had on hand as a wedge spacer. This configuration works very well to spread out the narrow vertical polars.
Chris
See also: https://www.diyaudio.com/community/...eil-at-140-that-is-the-question.331686/page-8
I put some measurements there before and after velours mod...
I put some measurements there before and after velours mod...
Fired up for the first time and had a big scare, as one channel was playing less loud than the other!
A bit of investigating and found out one of four AMT's came wired out of phase internally. Reversed the colored lead wires and Voila! Man, what FANTASTIC sound.
I suggest people check thier Heil's before using.
I can see what people are saying about 5kHz peak but sounds pretty pleasantly sparkly to me, especially with Heils replacing 1.4" compression driver/horn which has less pleasant peak 1-3kHz
A bit of investigating and found out one of four AMT's came wired out of phase internally. Reversed the colored lead wires and Voila! Man, what FANTASTIC sound.
I suggest people check thier Heil's before using.
I can see what people are saying about 5kHz peak but sounds pretty pleasantly sparkly to me, especially with Heils replacing 1.4" compression driver/horn which has less pleasant peak 1-3kHz
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Woofers are 8" Seas Curv cones and sound great in midrange with me switching among 1.4" compression driver, 1" compression driver, Beyma TPL150H, and now Heil stack using active crossover.
I already have the velours. Trying to see if I want to try adding wings before or after velour so velour covers the wing too...
I tried damping the backwave in monopole, but I prefer the dipole sound. I do have pretty good mix of diffusors and absorbers in this room already..
Kind of reminds me of big Magnepan panels in that bit larger-than-life, rich, natural midrange. Not pin-point imaging but air-infused pleasantries.
I already have the velours. Trying to see if I want to try adding wings before or after velour so velour covers the wing too...
I tried damping the backwave in monopole, but I prefer the dipole sound. I do have pretty good mix of diffusors and absorbers in this room already..
Kind of reminds me of big Magnepan panels in that bit larger-than-life, rich, natural midrange. Not pin-point imaging but air-infused pleasantries.
Drawing inspiration from other people making Wings for Heil AMT's:
https://community.klipsch.com/index...with-wings-possible-kit-for-heritage/page/22/
Some of the wooden wing designs seem like a lot of work, and I don't see why the wing material needs to be wood. Looking at some easier-to-make alternatives, but for now I stuck the velour sheets in sort of a wing configuration to see how sound changes. It changes a lot but not sure I like the direction it's going, e.g. fuller lower ranges of vocals but less sparkle and air..
https://community.klipsch.com/index...with-wings-possible-kit-for-heritage/page/22/
Some of the wooden wing designs seem like a lot of work, and I don't see why the wing material needs to be wood. Looking at some easier-to-make alternatives, but for now I stuck the velour sheets in sort of a wing configuration to see how sound changes. It changes a lot but not sure I like the direction it's going, e.g. fuller lower ranges of vocals but less sparkle and air..