Yes a large 3ohm eater can stress some amps.heil goes on sale again i will own two , please let me know , black friday maybe ,ALSO to respond about that 2 way comment, 4 big heils wired together in series will make midrange , at the loss of clean hi's , if its a 2way design make sure the woffer is extreem quality and goes above 4000hz
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A lot what you say is debatable...
- The Heil is a squawker, not a tweeter.
- Many amps should have little trouble driving a 3 ohm resistive load. Except for maybe some tube amps. But adding 3 ohm resistance would lower the sensitivity with 6 dB, probably also a pity with tube amps.
- A 2 uF first order at 3 ohm gives a 26.5 kHz crossover, probably not what you want. By adding 3 ohm it will be half of that, still far too high.
- Adding 40-60 uF as protection is fine as long as further filtering is done in digital/analog domain.
- IMHO it is a pity to use a Heil AMT too high. It can be used fine for mid-high duties. It can be 112 dB at 1 kHz, and at less than 1% distortion still. Unless you have a ball room as home or do regularly some head-banging, the new Heil can handle mid frequencies (4th order around 750-1000 Hz).
- The Heil is a squawker, not a tweeter.
- Many amps should have little trouble driving a 3 ohm resistive load. Except for maybe some tube amps. But adding 3 ohm resistance would lower the sensitivity with 6 dB, probably also a pity with tube amps.
- A 2 uF first order at 3 ohm gives a 26.5 kHz crossover, probably not what you want. By adding 3 ohm it will be half of that, still far too high.
- Adding 40-60 uF as protection is fine as long as further filtering is done in digital/analog domain.
- IMHO it is a pity to use a Heil AMT too high. It can be used fine for mid-high duties. It can be 112 dB at 1 kHz, and at less than 1% distortion still. Unless you have a ball room as home or do regularly some head-banging, the new Heil can handle mid frequencies (4th order around 750-1000 Hz).
I use a 15" Eminence bass, a 8" Tang Band midrange and the ESS, so I have to cross over to the 8" TangBand. If the original crossover was 800 Hz, I suppose that would mean 3200 Hz for me.
That is what I am doing now, but I think the ESS is ´screaming´ a little. I am not fully satiesfied with it as it is.
It might be breakup at the self ressonance, 500 Hz or the peak at 5 Khz.
That is what I am doing now, but I think the ESS is ´screaming´ a little. I am not fully satiesfied with it as it is.
It might be breakup at the self ressonance, 500 Hz or the peak at 5 Khz.
I have 1b bookshelf modified for biamp/ crossover bypass switch (so I can dsp them or run them factory/passive, bookshelf 1b xover at 1k, tower at 800Hz) IMO you are wasting some of the big amt potential if your cross them much over 1200 Hz. My next amt build will be amt/sealed 8” mid-bass/sub xover at around about 100/1000...hopefully it’s the ring to rule them all. I also have ess ps1220 with midsize amt/4” mid/sub. They are amazing but I wish they had the airy, spacious magic bs I get from the big amts
ESS built the AMT6 professional which has a horizontal array of 4 big amts on top of 2 12”
ESS built the AMT6 professional which has a horizontal array of 4 big amts on top of 2 12”
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The main question was: Did I choose the right crossover frequency?
Maybe I answered that myself. What I really wanted was an opinion on if the AMT works like any other tweeter, or if it is possible to cross it lower, and the reason why it should be possible.
And maybe as a side effect: Somebody chiming in around the 2 problem frequencies 500 Hz (fs) and the peak at 1500 Hz.
I think you'd be a mile ahead if you got yourself a cheap usb measurement mic paired with REW. ESS diaphragms measure differently and I'd imagine a "general" response could be similar between each but then again, the response may not be. You should measure.
I've noticed that pleated diaphragms of this size/type have a similar "general" curve to their frequency response, even between other manufacturers offerings like Beyma etc. I'd did a little modification to my diaphragms that flattened some of the severe peaks but even without that you could get a pretty flat response with just a couple of PEQ filters.
The lowest I crossover my pair is around 1khz using a 4th order butterworth filter. The butterworth filter boosts the lower cutoff of the heil (in this frequency range) and produces a flat, summed, response. Even with the xo filters' boost, the diaphragms needed a little PEQ lift to smooth out the cutoff slope. Moving the crossover point up to around 1.2khz the diaphragms don't need any help on the cutoff slope at all. At this setting (1.2khz) I can also use a 2nd order butterworth filter. Both crossover points sound fine even when driven to high SPL. Using a LR4 filter at either of these points lowers the summed response about 2db. Gives the speaker a bit more of a "laid back" sound in the midrange. To each their own here.
I know quite a few people state that they crossover pretty low with the heil. I can only guess that they lower the whole upper frequency response a ton to get a good highpass slope shape. The compromise would be lower efficiency of the heil driver or even more eq applied. I didn't/couldn't make that compromise. My older DSP allows (2) peq filters in the upper drivers section. I need to work within that limitation. I chose a well mannered 15" woofer that allows me do do that. A decent 12" woofer should be no problem for anybody considering a 2-way design with the heil, no mid driver needed, in either case.
Once you achieve a flat response on the heil, a nice 2db decline in magnitude over the whole frequency range seems to me to make for a nice sounding speaker.
Hope that helps.
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I agree 100%, so does Dr.Heil/ESS the 1b towers were crossed over at 800 but raised it to 1000 for the 1b bookshelf’s and raised it to 1000-1200 on later versions of the towers.
These ‘few people’ include Dr.Heil and Nelson Pass (who worked at ESS for.a time) The wiki states 650Hz. I believe most of this is in theory but as I stated above in practice ESS started at 800 and moved up. I couldn’t/wouldn’t make that compromised either.
I love my 1b bookshelf’s but the best way to cover 20-1200 Hz can certainly be debated.
I have a 1st generation pair myself and we need to remember that the original diaphragms were made from polyethylene and had a higher pleat count. My thinking on the higher xo frequency had to do with failure rate, too. You could scorch the originals with high spl as the pleats began to deform with age. I'm sure raising the xo back then helped with that as well.
I would advise to measure and then do EQ to flatten your system. You can do EQ on PC side, with a DSP solution like mini DSP HD or buy Hypex Fusion plate amps. The last option will also ensure a very low THD DAC and amp.
For first order, I think 3k2 crossover is about right. If you like to stay passive, you could try 2nd order at around 2k. Below this, the AMT needs some shelving. But with active driving, more is possible. And with EQ the AMT will sound very very clean and nice!
For first order, I think 3k2 crossover is about right. If you like to stay passive, you could try 2nd order at around 2k. Below this, the AMT needs some shelving. But with active driving, more is possible. And with EQ the AMT will sound very very clean and nice!
I found a peculiar problem with my AMTs. The impulse behavior of my left and right speaker channels were different. Most of the times I only measure the right channel so I found the problem pretty late. It turns out that the left AMT had inversed polarity! Either its internal wires are wrongly soldered, but more likely the diafragma is mounted in the wrong direction. I fixed the polarity by mounting the thick blue ground wire to plus. Stereo image is fixed now, but I still wonder whether the setup is fully optimal this way. Would a Heil diafragma send out sound exactly the same forwards and backwards? How hard would it be to remount the diafragma?