Just FYI, DROP has ESS Heil speakers with two 6" woofers/side for $850/pair. Looks like a smaller version of Great Heil AMT and nicer looking and cheaper than 2019 Drop of similar speaker with only one 6" woofer for $1400/pair.
Drop: Passions lead here (formerly Massdrop)
Drop: Passions lead here (formerly Massdrop)
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Hi ! can you do a complete Cumulative Spectral-Decay plot maybe for all the tweeter working range ?
anyway it would be telling to compare this impulse response with the one from a more conventional driver used to cover the same audio range. Maybe it is not that different ? usually dome mids/tweeters have big magnets and light diaphragms .... they are naturally fast. Settling time can be an issue ? ... maybe
I only compared to my other measurements of compression drivers on horns. I do not know how to make a proper CSD plot in REW, I only can do the waterfall. Here are three measurements to compare. The AMT just looks as the best to me (not by much).
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I made a mistake to subscribe to their newsletter. This is just a torture for me, since I need the money for something else at the moment
Thank you very much indeed for these extremely valuable plots. Yes it looks like the Amt driver is really the best at least at the testing level ... i am a little unimpressed by the compression drivers. I really do not have any idea if the guilty for these little ripples are the drivers or the horns
... maybe both Amt driver is the winner ! Thanks a lot again, gino
Unfortunately i know almost nothing. We all know the ideal behaviour and actually the Amt driver with this testing conditions approaches the ideality very very much.
I have only the feeling that this test is very very telling ... very.
Loudspeaker designer John Dunlavy: By the Numbers... | Stereophile.com
i subscribe to this party ... except for voicing. Speakers performance is heavily room dependent. I would try to make a speaker good in lab ... and then optimize its positioning in the listening room. And the room of course.
Test unit for first measurements is built up. All held together by two M6 threaded rod, with some polyfil inside the 3FE22 cover, which are almost exactly 0.75 l each. All mounted to a corrugated cardboard baffle.
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To be a bit more specific. I noticed that the acoustic low pass of the 3FE22s is around 1.35 kHz, so they should blend in perfectly with the AMT. Paralel combination has higher sensitivity than the AMT and the series combination has a strange distortion peak in the measurement, I hope it is just a glitch. I need to print the horn now, but my large printer is out of order at the moment.
3D printing a large horn brings in large problems, so I decided to get my own CNC to cut foam for prototypes and plywood for final speakers. Since 2D cutting is much easier than 3D, I think one of the first things built will be a dipole speaker with AMT and Deltalite II 2515 I have laying around. With minimal baffle for the 15" and a minimal holder for the AMT. Large CNC'd horns will follow later - starting with something that could seem as waste of machine time - by cutting out and milling angles from flat panels for a bwaslo style synergy horn.
ESS Heil mods
Pelanj and Pharos:
Been keeping abreast of your projects with great interest. I have a pair of the large ESS, using them at 800hz on a vintage speaker for the last year. Really like them. I'm ready to do a build with some off the shelf things I already own. It would look similar to Pharos's ESS build, but with a 12" TAD 1201H mid-bass, from about 200-800. All active, and the amps are here.
Read up on the Klipsch site about their efforts with double stacking & wings. They stress the importance of distance of the ESS from the front edge. They comment about a single ESS losing some pattern control below 2000, which makes me wonder if an upper mid in the 5"-8" size range would be a reasonable option with a single ESS? Crossed over at 2500 or so. Either way, the cost would be roughly the same, so that isn't a consideration. I do like the look of the classic ESS speakers, and would like to buy a grill from ESS if it works out for the end result. Not sure about using my DIYSG 15" buyout woofers for the bottom end, so would use powered TAD subs that are sitting here sulking. (12" woofers with passive radiators)
I realize this flies in the face of the double stack idea....but I'd happily order another pair and build some wings if that makes more sense.
Comments? Thanks....
Pelanj and Pharos:
Been keeping abreast of your projects with great interest. I have a pair of the large ESS, using them at 800hz on a vintage speaker for the last year. Really like them. I'm ready to do a build with some off the shelf things I already own. It would look similar to Pharos's ESS build, but with a 12" TAD 1201H mid-bass, from about 200-800. All active, and the amps are here.
Read up on the Klipsch site about their efforts with double stacking & wings. They stress the importance of distance of the ESS from the front edge. They comment about a single ESS losing some pattern control below 2000, which makes me wonder if an upper mid in the 5"-8" size range would be a reasonable option with a single ESS? Crossed over at 2500 or so. Either way, the cost would be roughly the same, so that isn't a consideration. I do like the look of the classic ESS speakers, and would like to buy a grill from ESS if it works out for the end result. Not sure about using my DIYSG 15" buyout woofers for the bottom end, so would use powered TAD subs that are sitting here sulking. (12" woofers with passive radiators)
I realize this flies in the face of the double stack idea....but I'd happily order another pair and build some wings if that makes more sense.
Comments? Thanks....
ESS
Pharos:
That is what I interpreted their comments to mean. They also stated that it was important to have a solid platform under the ESS. But others in the same thread talked about placing the ESS at the front, with the wings overhanging.
I'm trying to picture my relatively small box (under 2 cf exterior) for the 12", with the single or dual ESS on top, similar to your modified ESS speakers. Considered the idea of buying a Baltic birch knock-down cabinet to modify as a test case.
The idea of an inverted, truncated pyramid on the bottom to house a woofer or woofers is appealing to me, so this would end up at 3 or 4 way, which is not the goal for most of the stacked ESS crowd.
Pharos:
That is what I interpreted their comments to mean. They also stated that it was important to have a solid platform under the ESS. But others in the same thread talked about placing the ESS at the front, with the wings overhanging.
I'm trying to picture my relatively small box (under 2 cf exterior) for the 12", with the single or dual ESS on top, similar to your modified ESS speakers. Considered the idea of buying a Baltic birch knock-down cabinet to modify as a test case.
The idea of an inverted, truncated pyramid on the bottom to house a woofer or woofers is appealing to me, so this would end up at 3 or 4 way, which is not the goal for most of the stacked ESS crowd.
I have measured 360 degree dispersion, with the limitations you are facing when not having a Klippel system or anechoic chamber at hand.
It was gated, in steps, horizontal only (vertical dispersion is very limited anyway).
This was with one ESS great Heil latest gen., mounted in a 625mm wide baffle with a 15" Woofer above and below - that is however the only resemblance to the PAP Trio15. everything else is different.
Also for the ESS I do not expect a large part of the low end gain to be from the horn loading, as much as from the wings e.g. the baffle itself.
But I will be happy to stand corrected should anyone have more background info on this.
The ESS does have some lobing and narrow dispersion in the crossover region, that is part of why it matches the dispersion (beaming) of 12 & 15" units in the crossover/transition region around 600-1200Hz.
At some point I might get some of my other DIY projects closed down and get to summarize the measurements for sharing....
But have you seen the Klippel measurements published for the Trio15 Heil?
In my system with 2x Failtal Pro 15PR400, I ended up with 0.5mS delay on the tweeters to achieve proper time alignment, first indications were 0.44mS, but results were better in the null test for slightly more.
It seems sub-optimal, as on the backside of the dipole the delay then becomes worse.... but it did improve clarity and imaging precision, a welcome improvement on the rather narrow optimal listening window.
To me the really great thing, about the great Heil, is that it's possible to avoid having a x-over point above 1000Hz. I will fight long and hard to avoid that - anyway it's a tweeter yes, but with membrane area as a 7" driver
I am happy to say that I do not have any concerns about the transition from the 15" driver(s) to the ESS, it is an active system and some minor corrections are needed for linearity, part from that pretty seamless.
It was gated, in steps, horizontal only (vertical dispersion is very limited anyway).
This was with one ESS great Heil latest gen., mounted in a 625mm wide baffle with a 15" Woofer above and below - that is however the only resemblance to the PAP Trio15. everything else is different.
Also for the ESS I do not expect a large part of the low end gain to be from the horn loading, as much as from the wings e.g. the baffle itself.
But I will be happy to stand corrected should anyone have more background info on this.
The ESS does have some lobing and narrow dispersion in the crossover region, that is part of why it matches the dispersion (beaming) of 12 & 15" units in the crossover/transition region around 600-1200Hz.
At some point I might get some of my other DIY projects closed down and get to summarize the measurements for sharing....
But have you seen the Klippel measurements published for the Trio15 Heil?
In my system with 2x Failtal Pro 15PR400, I ended up with 0.5mS delay on the tweeters to achieve proper time alignment, first indications were 0.44mS, but results were better in the null test for slightly more.
It seems sub-optimal, as on the backside of the dipole the delay then becomes worse.... but it did improve clarity and imaging precision, a welcome improvement on the rather narrow optimal listening window.
To me the really great thing, about the great Heil, is that it's possible to avoid having a x-over point above 1000Hz. I will fight long and hard to avoid that - anyway it's a tweeter yes, but with membrane area as a 7" driver
I am happy to say that I do not have any concerns about the transition from the 15" driver(s) to the ESS, it is an active system and some minor corrections are needed for linearity, part from that pretty seamless.
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I cannot really see the need for a stacked pair, they are quoted as 100dB sensitivity, but then you are in the States and have larger rooms than we do. An average woofer or midwoofer it will be around 90dB. Audio International said to me that the Heil will take 1kW peak, and they certainly fill the air in a way that has entranced me.
The sense of 'air' tends to make me think that off axis energy is not a problem.
I might even kick out my ADAM Betas in favour of my ESS rebuild, and revamp them with new diaphragms, which seem to be good, and better than the yellow ones I bought. Also a grille refurbishment.
I have always seen the Heil with its lower front horn edge flush with cabinet tops, even in their earlier 'bookshelf' models. Was 2cf two cubic feet? That is about 55 litres, quite small for a 12". I think the pyramid is great from several standpoints, but in my case I would narrow it if working from scratch so that the rims of the woofer are supported by, and overlapping the side walls which are very rigid.
The sense of 'air' tends to make me think that off axis energy is not a problem.
I might even kick out my ADAM Betas in favour of my ESS rebuild, and revamp them with new diaphragms, which seem to be good, and better than the yellow ones I bought. Also a grille refurbishment.
I have always seen the Heil with its lower front horn edge flush with cabinet tops, even in their earlier 'bookshelf' models. Was 2cf two cubic feet? That is about 55 litres, quite small for a 12". I think the pyramid is great from several standpoints, but in my case I would narrow it if working from scratch so that the rims of the woofer are supported by, and overlapping the side walls which are very rigid.
I use the big ESS AMT together with 6" 18 sounds 6nd430 and 15" in open baffle. Works fine. I cross at 300 Hz and 1200 Hz currently, though I am still busy refining the filters...
Fedde