Loading, to me, means the impedance of the device, just as we refer to the "load" that the speaker presents to the amp. There is no relationship between the "loading" of a horn in this sense and the directivity. Which is why I was confused.
The larger the "box" the waveguide is in the better - infinite baffle is the best - because the lower diffraction. This is just another way of say that the more gradual and extended the "lip" the better. Its the same thing basically. Its all related to the "rate of change of slope" and the less of it there is the better. A figure of merit would be the integral of the "rate of change of slope" / "distance from the edge" in a closed loop around the device (in a plane containing the normal).
The larger the "box" the waveguide is in the better - infinite baffle is the best - because the lower diffraction. This is just another way of say that the more gradual and extended the "lip" the better. Its the same thing basically. Its all related to the "rate of change of slope" and the less of it there is the better. A figure of merit would be the integral of the "rate of change of slope" / "distance from the edge" in a closed loop around the device (in a plane containing the normal).
Last edited:
Certainly electrical load is a different issue. It's commonly used in horn talk to describe the bandwidth over which the directivity device is effective, which is how I use it in this context. But we're on the same page anyway.
And your explanation of the baffle is what I understood as well, thank you for taking the time to respond, it sure helps anyone reading this to "get" what's being said. The foam fun, to me, is just another way down the path. Because it's lossy, it requires less distance to do the job, compared to horn length or mouth size, but you are throwing away acoustic energy.
Loading is part of that great universal nomenclature in physics. I'd like a dollar for every time someone has tried to describe hydraulics or mechanics using Ohms law.
You may be right, but the way I see it you will have less of a reflection (backwave) with the baffle that would be due to the sudden change in loading when it spills over the edge. It may also not hurt that baffles aren't usually round.
In the hope that more of it is unwanted energy. IIRC, I lost a dB or two but with compensation for that, I prefer the sound.
🙂
The rate of change is the big part. With enough of a gentle roundover, it's not much of an issue, but then, we live in the real world without 48" horns. A rectangular baffle would certainly smooth the transition region via distance averaging.
That's a great thing with horns- you can give up a fair bit of power and still have something very sensitive 🙂 Makes lossy treatments very attractive.
I compared the stuff I got with what you use. About the same PPI. There was a difference, but not much. Yours had a few shiny surfaces, mine did not. Comparable thicknesses pass about the same amount of light. The stuff I bought worked. I got a big hunk and I filled up a large, (22"X5" mouth), and ugly sounding exponential horn with it and gained great improvement in sound quality - the honk practically disappeared. (Compared to a good waveguide that horn, even with foam, is not a great device).
I, for one, don't give my 15W amps a hard time. When the time comes, I may reclaim the few dB that I'm padding my tweeters and power them with a 1W amp.
Hi Paul,
That sounds all to familiar, damn aussies 😛
I created a thread on DTV (click here) to see if anyone had even heard a set of these speakers let alone owned them, the silence was deafening 🙁
Hopefully some day someone buys a pair (hopefully in Melbourne) and are willing to have me over for a listen 🙂 The Abbey 12a's look like the sweet spot.
That's pretty sad really (that he gave up the hobby). Maybe that is why audiophiles are so afraid of blind testing!
Is it possible to make a Unity type horn using a OS waveguide or are there complications?
The whole concept of a Unity horn and a waveguide are at odds. Waveguides seek to propagate singular wavefronts and as such require very specific wavefronts at their throat. The unity concept does not feed the horn in a manner that is consistant with the waveguide approach.
The design criteria of the two speakers is different. I believe you designed your speakers for the home, and fidelity was your goal. I believe the Unities were designed to solve a pro-audio problem, which is that multi-way horns don't array well and they're enormous.
An externally hosted image should be here but it was not working when we last tested it.
But both designs have some crossover. A Summa would make a fine pro audio speaker, and there is a nightclub in Portland that has a couple of speakers that look suspiciously like Gedlee Abbeys. (:: THE WOODS - PORTLAND ::)
And a Unity horn makes a fine home speaker, as well as a prosound speaker.
Based on listening to both of them, I think the Summa images better, due to the superior termination of the waveguide and an inert cabinet that does a great job of "disappearing."
While the OS waveguide will offer limited benefits to the midrange of a Unity horn, the compression driver in a Unity horn is still covering four octaves of bandwidth, and would see benefits from the OS profile I think.
The main problem with the commercially available OS waveguides, in the context of a Unity horn, is that the coverage angle is too wide. (Makes it impossible to get the midranges close enough to the compression driver.)
Which is why I made my own mold back in 2006, as detailed on audiogroupforum
[/font]
Member
Joined 2009
To restate this question, can we look into mounting woofers on the waveguide with the goal to minimize the ill effects on the vertical axis caused by the long distance between the tweeter and woofer in the crossover region?
The waveguide may strictly shape the response above the crossover region and have no effect on the woofer.
But a waveguide with woofers in the walls will seriously degrade the performance of the HF response. I've designed a lot of the "woofers/mids" in the horn walls types of systems and they never can compete with a stand alone waveguide above the crossover. At crossover they both have problems - neither approach is ideal. I'll take the near ideal HF performance of the solo waveguide any day.
The Summa was originally designed for "clubs", not really large scale venues however. The systems themselves array well up to about four units, but above that and they begin to fall appart because you can get them close enough together. If you need more than four 1" HF compression drivers per channel, then you need to find another solution, but at anything less than that, I'd claim the Summa to be the better option.
I was in a club that had four Summas and about 12 subs - it would play insanely loud, albeit we did have some trouble with a few blown HF drivers for awhile. We found that we needed to limit the HF response above 10 kHz because the DJs would be clipping the amps almost all the time and all the HF energy would burn out the VC. Limit this energy (ie. don't clip the amps or use a LP filter) and we didn't have any more trouble.
The Summa was originally designed for "clubs", not really large scale venues however. The systems themselves array well up to about four units, but above that and they begin to fall appart because you can get them close enough together. If you need more than four 1" HF compression drivers per channel, then you need to find another solution, but at anything less than that, I'd claim the Summa to be the better option.
I was in a club that had four Summas and about 12 subs - it would play insanely loud, albeit we did have some trouble with a few blown HF drivers for awhile. We found that we needed to limit the HF response above 10 kHz because the DJs would be clipping the amps almost all the time and all the HF energy would burn out the VC. Limit this energy (ie. don't clip the amps or use a LP filter) and we didn't have any more trouble.
The Unity/Synergy Horns are very interesting to me but I don't have the machine tools (or AC in the shop) to build such a device. Heard rumblings about a 5" co-axial driver coming out of Danley Sound Labs that might be offered DIY complete with the horn.
Not sure about the rumors but DSL is very open with their designs and the DIY community in general. If it is true, I'm sure Patrick will be at the head of the line to get the kit.
Not sure about the rumors but DSL is very open with their designs and the DIY community in general. If it is true, I'm sure Patrick will be at the head of the line to get the kit.
Were they much like the Unity/Synergy horn?
In many ways the Synergy is ideal and yet the holes interfering with the HF waveguide seems to be perhaps the biggest problem. Otherwise it's a clever way around a lot of things, especially the problems associated with a horn loaded midrange.
Now, here is another interesting one to throw into the mix. Genelec studio monitors:
An externally hosted image should be here but it was not working when we last tested it.
You have a 3 way design with a 1" compression driver, 5 or 6" mid then dedicated woofers. Mid and CD share a "waveguide" (perhaps not technically correct use of the term but I use it in the sense that the intent is to control directivity.
Here is the response:
While not perfect, the response appears to achieve pretty good control over dispersion, the power response looks very good and extends flat a long way down.
Crossover points are 400 Hz and 3.5k. I wonder if it could be improved with a lower CD xo point where extreme SPL isn't needed. Normally I would think a 6" would need about 2k xo.
I do have some reservations about a large midrange driver running up to a CD, mainly due to the issue of breakup. With a 5 or 6" mid it's less of a concern and breakup could be pushed up higher further away from the passband. Normally it would mean pushing directivity control up higher as well, perhaps an octave higher than the Summa, but where you put a waveguide on the mids as well then you have some more flexibility. However, the design is also complex with more to go wrong. I wonder as well if the HF waveguide isn't compromised to allow closer driver spacing.
Interested to hear your thoughts Earl.
This could be a very cool DIY project. DE250 CD + AE TD6H mid + AE TD18H with xo optimised for best polar smoothness perhaps more like 1.5 - 2k. Built in to a large bass trap "soffit style" arrangement. I'm a bit tempted to try all 3 in that kind of arrangement. (In time I probably will).
Okay, next question. 😀
What would be the consequence of something like a 110db/octave or even higher, FIR filter (besides cost of going active, I know I know 😀 ).
From what i've seen - at least for typical a hi fi speaker , these ultra high order filters really seem to do a number on vertical lobing - they narrow the lobe so much that it becomes one of those "high Q artifacts" rather than an issue.
All of my Unity horn projects have been for the car. That's made it a bit challenging to do a head-to-head comparison against my Summas, since the environment is so different.
For the first time ever, I have a Synergy horn here that's intended for a living room. It's very very very early in the design process. But I've measured and EQ'd it, and it's definitely in a 'listenable' state.
Seven years ago I built a Unity horn mostly due to the internet hype, particularly inspired by John Sheerin's project. From the very first moment, I could tell it was something special. In the car it imaged in a way that I've never heard. For instance, on heavily processed recordings the soundstage had height that stretched to the floor, and the stage would occasionally exceed the width of the car. When the recording was tiny, so was the sound. So it wasn't that the Unity was blowing things out of proportion, it just had a way of extracting things in the recording that I'd never heard.
My new horn does that as well, but it sounds much much cleaner. I would say that the first thing that I noticed about the LeCleach horn is that it doesn't sound like a horn. If you weren't looking at a horn, you would think that you were listening to a direct radiator.
This is actually a good *and* a bad thing. I've built a lot of waveguides and conical horns, and there is something about the LeCleach that is very neutral. There's seems to be a bit of an 'art' to conical horns, where sometimes you can take a driver that sound crummy as a direct radiator, but when you bolt it to a conical horn the driver sounds excellent. An example of this is the cheap Goldwood cone tweeters. On a conical horn, those $5 tweeters make a fine midrange.
The LeCleach doesn't seem to do that; to my ears, the sound is very similar to a conventional two-way. In a good way.
Now that I have a working Synergy horn in my living room, the most striking aspect of the speaker is how detailed it is. I know that this is a hokey way to describe a speaker, but the best comparison I could make is between a DVD and a BluRay. The BluRay extracts tiny details in the image, and you're constantly aware of how sharp everything is.
I've been listening to 'Passion Pit' constantly for the past few months, and when I played it over the Synergy Horn, I instantly noticed things in the recording that I didn't know were there. For instance, in the song "Little Secrets" there's a low frequency melody that's looped throughout the entire song. On my other speakers I can perceive the notes in the loop; on the Synergy horn I can hear that the melody in the song has a subtle vibrato applied. Not a lot; just a little. But I've heard that track a hundred times and I didn't know that was there until yesterday.
Last night I played one of my girlfriend's favorite albums, and she remarked about how she'd never noticed how much the singers voice was processed. It was interesting to put modern recordings on and you can tell in mere seconds if a singer is cooking their vocals.
If you're the type of audiophile that likes speakers that are microscopes on the recording, this Synergy horn is for you. The amount of detail is just mind boggling. I can literally hear noise gates switch off in between notes. (Not just at the end of a song, or between tracks. Literally between *notes.*)
I can hear occasional sounds in the studio, buried in the noise floor.
This thing is nuts. I think I can safely say it's the most revealing loudspeaker I've ever had in my home.
There's a bit of a dark cloud hanging over this review, unfortunately. This morning I was doing what I normally do, day in and day out. I was getting some work done on my laptop, while listening to music. And I found myself stopping the music frequently, or turning it down.
At first, I thought nothing of this. But then I realized something: I never do that with my Summas. At all. My Summas are unique in that I can listen to them for hours at a time, day in, day out. I never touch the volume dial, never stop the music.
This is very interesting to me; and perhaps evidence that HOMs or thermal modulation is a problem here. (The holes in the wall of the Synergy Horn will certainly create diffraction.)
One thing that's a bit of a bummer about this is that the LeCleach horn profile sounds like what people expect a HiFi speaker to sound like. The narrower beamwidth at high frequency sounds similar to what a dome tweeter on a baffle sounds like. The Summa *doesn't* sound the same, because of it's wider beamwidth.
I'll keep documenting the project on my thread named "Monster Massive."
If it's HOMs that I'm hearing, I hope that I can minimize them. It would be fantastic if I could combine the incredible dynamics and smoothness of the Summas with the x-ray detail of the Synergy Horn. (And it's no wonder that Tom's Jericho horns are so successful. Can you imagine going to a rock concert and being able to hear the shimmer and decay of a cymbal in a live venue? Only a point source can do that.)
And I want to stress that the 'smoothness' of the Summas isn't just a frequency response thing. There is clearly something going on with the waveguide, because the Summas at 120dB sound as relaxed as a normal speaker at 100dB. They're a speaker that simply demands to be played loudly.
For the first time ever, I have a Synergy horn here that's intended for a living room. It's very very very early in the design process. But I've measured and EQ'd it, and it's definitely in a 'listenable' state.
Seven years ago I built a Unity horn mostly due to the internet hype, particularly inspired by John Sheerin's project. From the very first moment, I could tell it was something special. In the car it imaged in a way that I've never heard. For instance, on heavily processed recordings the soundstage had height that stretched to the floor, and the stage would occasionally exceed the width of the car. When the recording was tiny, so was the sound. So it wasn't that the Unity was blowing things out of proportion, it just had a way of extracting things in the recording that I'd never heard.
My new horn does that as well, but it sounds much much cleaner. I would say that the first thing that I noticed about the LeCleach horn is that it doesn't sound like a horn. If you weren't looking at a horn, you would think that you were listening to a direct radiator.
This is actually a good *and* a bad thing. I've built a lot of waveguides and conical horns, and there is something about the LeCleach that is very neutral. There's seems to be a bit of an 'art' to conical horns, where sometimes you can take a driver that sound crummy as a direct radiator, but when you bolt it to a conical horn the driver sounds excellent. An example of this is the cheap Goldwood cone tweeters. On a conical horn, those $5 tweeters make a fine midrange.
The LeCleach doesn't seem to do that; to my ears, the sound is very similar to a conventional two-way. In a good way.
Now that I have a working Synergy horn in my living room, the most striking aspect of the speaker is how detailed it is. I know that this is a hokey way to describe a speaker, but the best comparison I could make is between a DVD and a BluRay. The BluRay extracts tiny details in the image, and you're constantly aware of how sharp everything is.
I've been listening to 'Passion Pit' constantly for the past few months, and when I played it over the Synergy Horn, I instantly noticed things in the recording that I didn't know were there. For instance, in the song "Little Secrets" there's a low frequency melody that's looped throughout the entire song. On my other speakers I can perceive the notes in the loop; on the Synergy horn I can hear that the melody in the song has a subtle vibrato applied. Not a lot; just a little. But I've heard that track a hundred times and I didn't know that was there until yesterday.
Last night I played one of my girlfriend's favorite albums, and she remarked about how she'd never noticed how much the singers voice was processed. It was interesting to put modern recordings on and you can tell in mere seconds if a singer is cooking their vocals.
If you're the type of audiophile that likes speakers that are microscopes on the recording, this Synergy horn is for you. The amount of detail is just mind boggling. I can literally hear noise gates switch off in between notes. (Not just at the end of a song, or between tracks. Literally between *notes.*)
I can hear occasional sounds in the studio, buried in the noise floor.
This thing is nuts. I think I can safely say it's the most revealing loudspeaker I've ever had in my home.
There's a bit of a dark cloud hanging over this review, unfortunately. This morning I was doing what I normally do, day in and day out. I was getting some work done on my laptop, while listening to music. And I found myself stopping the music frequently, or turning it down.
At first, I thought nothing of this. But then I realized something: I never do that with my Summas. At all. My Summas are unique in that I can listen to them for hours at a time, day in, day out. I never touch the volume dial, never stop the music.
This is very interesting to me; and perhaps evidence that HOMs or thermal modulation is a problem here. (The holes in the wall of the Synergy Horn will certainly create diffraction.)
One thing that's a bit of a bummer about this is that the LeCleach horn profile sounds like what people expect a HiFi speaker to sound like. The narrower beamwidth at high frequency sounds similar to what a dome tweeter on a baffle sounds like. The Summa *doesn't* sound the same, because of it's wider beamwidth.
I'll keep documenting the project on my thread named "Monster Massive."
If it's HOMs that I'm hearing, I hope that I can minimize them. It would be fantastic if I could combine the incredible dynamics and smoothness of the Summas with the x-ray detail of the Synergy Horn. (And it's no wonder that Tom's Jericho horns are so successful. Can you imagine going to a rock concert and being able to hear the shimmer and decay of a cymbal in a live venue? Only a point source can do that.)
And I want to stress that the 'smoothness' of the Summas isn't just a frequency response thing. There is clearly something going on with the waveguide, because the Summas at 120dB sound as relaxed as a normal speaker at 100dB. They're a speaker that simply demands to be played loudly.
Last edited:
Do you think a larger horn like the JMLC-270 that can cover 500-18Khz with a carefully selected 1.4" compression driver would get closer to the "x-ray detail" of the Synergy by maintaining controlled directivity down to say 500Hz?
Additional listening impressions of a JMLC-270 would be welcome.
Attachments
Thanks, Patrick for your detailed impressions of the most interesting horn/waveguide systems. They mirror my own experience (except I haven't heard a Synergy yet). The spatial impression of an OS and a LeCleac'h horn are strikingly different, yet both have very good impulse response. It's hard to describe unless you've heard it for yourself, and people who have only heard the not-so-good horns at hifi shows won't know what you're talking about.
Purely a guess, but people who like MBL's, dipoles, and classical music may favor the LeCleac'h, while people who like snap, resolution, and jazz/rock may favor the OS profile. In the next sentence, I take what I just said back, since there are lots of ways to get both OS and LeCleac'h wrong, and I'm not sure equivalent comparisons can be made.
Purely a guess, but people who like MBL's, dipoles, and classical music may favor the LeCleac'h, while people who like snap, resolution, and jazz/rock may favor the OS profile. In the next sentence, I take what I just said back, since there are lots of ways to get both OS and LeCleac'h wrong, and I'm not sure equivalent comparisons can be made.
Last edited: