The Synergy horn does not preserve time, but rather phase!
A square wave is no measure of time.
A 360 degree phase shift will maintain a perfect square wave.
You do not have the drivers time aligned but rather phase aligned.
Moving from one note to another can move the sound from one driver to another thus sounding like the instrument has moved.
This can be shown using cepstrum or equivalent TEF measurement
I'm not saying your design is not excellent only that there can be improvement one day as technology allows.
It only applies certain situations.
My home theater is an LEDE so, there are no early room reflections and directivity does not matter.
well, I'm right now sitting 3 feet from a 3way speaker with 12" woofer
can't hear the sound coming form one driver or anything other weird things happening
and if I stand up the sound only moves slightly towards the other channel
nothing weird there either, other than me doing it
but sounds fine, and just the same as if I'm 10 feet away
can't hear the sound coming form one driver or anything other weird things happening
and if I stand up the sound only moves slightly towards the other channel
nothing weird there either, other than me doing it
but sounds fine, and just the same as if I'm 10 feet away
Well at this point I need to hear the best of them. I'm am in a great position to hear what they bring to the table and see if they are or are not the best possible trade off. You guys have certainly high lighted possible issues that I should be aware of. This has got to be investigated by mixing mastering guys it is after all the first truly new horn tech since the 30s.
Hi All
I am not sure where to start here so I will only offer some thoughts.
The most noticeable thing you hear with any loudspeaker normally is the frequency response related things. With the Synergy horns we sell, they are not voiced like hifi speakers usually are, with a sloped off frequency response which is desirable especially listening to CD’s (which to sound different than LP’s started off life being brighter). The reason is normally the closest listener for an SH-50 (normally in the air) would be more like 40 or 50 feet and the farthest maybe 150-200 feet. Remember too, the hf end is absorbed by air relative to a living room listing distance of perhaps 10 or 15 feet.
Calculation method of absorption of sound by atmosphere air damping dissipation absorbtion - Attenuation of sound during propagation outdoors outdoor - sengpielaudio Sengpiel Berlin
Like I said before, the first thing that needs to be done to the system to make a hifi version is to add that roll off slope like Toole and others have identified as being the ideal. They are bright without that in a living room setting.
After the overall response shape comes the ups and downs especially through the mid range where your ears have its greatest acutely. As I explained earlier, to do this takes more components, for an SH-50 which can handle over 500 Watts before the response shape even changes 3dB, the parts are all large and expensive and there is a point where you say ok, for a movie theater or corporate presentation center, its time to stop. If I were making a hifi speaker, I could afford to use more parts and lower power drivers. Because of the low pass acoustic filters use d to couple the cones to the horn, the distortion, especially in the mid range for and SH-50 say, is far lower than a normal hifi loudspeakers and the headroom is way beyond anyone would ever use in a living room, all overkill.
I would also offer that the design of these was probably backwards from normal. I had nothing to go on so far as rules, the “rules” to follow were mostly the result of the prototype/ measurement/ modify loop. I use Akabak and other programs to model things but the model at least in the beginning usually evolves along with a measured result because the model is never exactly what you measure because of un accounted for elements and a proper measurement of the real thing, trumps a computer model of the real thing..
Earl is right, one can perturb a horn by having discontinuities, by experimentation and measurement I found that the pattern the horn without holes radiates, does not fill in the corners of a square or rectangular completely. The corner is not the same as the flat on a horn wall and the effect of having a hole in the horn wall can be very small depending on a number of “if’” stages such as the smaller the hole is, the farther away from the throat it is the smaller the perturbation. This rule here was found by measuring horn body’s with and without the holes. Another observation was that following Keeles pattern loss frequency formula, that when you’re at a frequency above the pattern control point, then the holes in that part of the horn have a small effect, if they are at a frequency below pattern control point, then they can be more significant. On most of our Synergy horns, the holes have a very small effect compared to no holes on the same body.
If I was making a hifi version and in fact I have a pair I have been slowly working on, I would begin with an SM60 horn. It has a nice smooth transition to the second flare angle and so doesn’t have the extra radiation outside the pattern up high that the SH-50 has. The level is well down but still present on the horn with the kink in the angles. The other good parts are the driver is a stock Coax unit that is adapted to the synergy horn and the hf source at the center continues down in conical horn to a small diameter.
I think this approach was in Fig7 of the Synergy patent but it took a good while before we were able to mold the horn economically. That driver also has a nice feature for hifi marketing in that its raw response goes to 20KHz, unusual for a compression driver.
One person asked about modulation. No, it’s not an issue normally, here’s why.
If you imagined a square horn, radiating one acoustic Watt and the throat was one inch square, you would have a power density of 1 Watt per square inch. Back by the compression driver though, the pressure or power density is much higher If the area were 1/10th that at the exit, the power density would be 10 Watts per square inch. If the mid drivers tapped in where the area is more like 10 square inches, the power density there is 1/10th Watt per square inch. As one can see, the power density and pressure it MUCH greater for the hf driver than the mid drivers so the hf driver doesn’t feel the mid drivers appreciably.. Same for the woofers, where they tap in, the power density is much lower than at the mids and those drivers move more air but at an even lower pressure.
Bottom line, are they perfect? No what is and addressing every wart costs money. What the design lets you do is combine multiple driver is away that very much acts like a single crossover less driver. For a given SPL It produces less harmonic distortion than the same drivers would if radiating individually. How much effort one puts into making that happen and how difficult that is, is at least partly related to the acoustic power you need to produce. What is not obvious is that a speaker like an SH-50 is AT LEAST 6 dB more powerful than a full size voice of the theater speaker and goes higher and lower.
Art is right too, I have not been able to get the company very interested in hifi . We don’t advertise much at all, we have never put a system out with any famous bands on tour. But by having a better product and allowing the venue owners and system designers to hear what a few of our Synergy horns can do side by side with the best and baddest the big companies can offer at any price, we have grown very significantly every year. In the last few months The Buffalo Bills, Boise State, LSU (the loudest stadium in the US) Nationwide arena as well as a good number of smaller college and high schools sports venues and large Churches have installed our Synergy horns.
Against that open green pasture, horn hifi appears to be a quirky market with a lot of Voodoo, horn folk lore and preconceptions. On the other hand, hifi is my hobby and it was Dick Heysers writing that made the idea of a single source in time and space loudspeaker interesting combined with an old friends comment, “there are speakers that sound goo, there are speaker that go loud but none that do both”, sounded like a target to me I thought.
Earl I have a pair of SM-60’s here in parts and have been slowly working on in my spare time, what would be an stock black ugly looking but very good measuring pair of speakers.
I would like to hear your speakers and want to talk to you about a crazy high intensity acoustics thing not a loudspeaker as well. I would like you to hear a Synergy horn too and see how they measure with your technique and see it’s nice impulse response. We hear with our ears not our measurements after all. After the middle of next month, things will be easing up at work and I should be able to get these put together by then so I will bring them up your way when I visit my brother.
Best,
Tom
I am not sure where to start here so I will only offer some thoughts.
The most noticeable thing you hear with any loudspeaker normally is the frequency response related things. With the Synergy horns we sell, they are not voiced like hifi speakers usually are, with a sloped off frequency response which is desirable especially listening to CD’s (which to sound different than LP’s started off life being brighter). The reason is normally the closest listener for an SH-50 (normally in the air) would be more like 40 or 50 feet and the farthest maybe 150-200 feet. Remember too, the hf end is absorbed by air relative to a living room listing distance of perhaps 10 or 15 feet.
Calculation method of absorption of sound by atmosphere air damping dissipation absorbtion - Attenuation of sound during propagation outdoors outdoor - sengpielaudio Sengpiel Berlin
Like I said before, the first thing that needs to be done to the system to make a hifi version is to add that roll off slope like Toole and others have identified as being the ideal. They are bright without that in a living room setting.
After the overall response shape comes the ups and downs especially through the mid range where your ears have its greatest acutely. As I explained earlier, to do this takes more components, for an SH-50 which can handle over 500 Watts before the response shape even changes 3dB, the parts are all large and expensive and there is a point where you say ok, for a movie theater or corporate presentation center, its time to stop. If I were making a hifi speaker, I could afford to use more parts and lower power drivers. Because of the low pass acoustic filters use d to couple the cones to the horn, the distortion, especially in the mid range for and SH-50 say, is far lower than a normal hifi loudspeakers and the headroom is way beyond anyone would ever use in a living room, all overkill.
I would also offer that the design of these was probably backwards from normal. I had nothing to go on so far as rules, the “rules” to follow were mostly the result of the prototype/ measurement/ modify loop. I use Akabak and other programs to model things but the model at least in the beginning usually evolves along with a measured result because the model is never exactly what you measure because of un accounted for elements and a proper measurement of the real thing, trumps a computer model of the real thing..
Earl is right, one can perturb a horn by having discontinuities, by experimentation and measurement I found that the pattern the horn without holes radiates, does not fill in the corners of a square or rectangular completely. The corner is not the same as the flat on a horn wall and the effect of having a hole in the horn wall can be very small depending on a number of “if’” stages such as the smaller the hole is, the farther away from the throat it is the smaller the perturbation. This rule here was found by measuring horn body’s with and without the holes. Another observation was that following Keeles pattern loss frequency formula, that when you’re at a frequency above the pattern control point, then the holes in that part of the horn have a small effect, if they are at a frequency below pattern control point, then they can be more significant. On most of our Synergy horns, the holes have a very small effect compared to no holes on the same body.
If I was making a hifi version and in fact I have a pair I have been slowly working on, I would begin with an SM60 horn. It has a nice smooth transition to the second flare angle and so doesn’t have the extra radiation outside the pattern up high that the SH-50 has. The level is well down but still present on the horn with the kink in the angles. The other good parts are the driver is a stock Coax unit that is adapted to the synergy horn and the hf source at the center continues down in conical horn to a small diameter.
I think this approach was in Fig7 of the Synergy patent but it took a good while before we were able to mold the horn economically. That driver also has a nice feature for hifi marketing in that its raw response goes to 20KHz, unusual for a compression driver.
One person asked about modulation. No, it’s not an issue normally, here’s why.
If you imagined a square horn, radiating one acoustic Watt and the throat was one inch square, you would have a power density of 1 Watt per square inch. Back by the compression driver though, the pressure or power density is much higher If the area were 1/10th that at the exit, the power density would be 10 Watts per square inch. If the mid drivers tapped in where the area is more like 10 square inches, the power density there is 1/10th Watt per square inch. As one can see, the power density and pressure it MUCH greater for the hf driver than the mid drivers so the hf driver doesn’t feel the mid drivers appreciably.. Same for the woofers, where they tap in, the power density is much lower than at the mids and those drivers move more air but at an even lower pressure.
Bottom line, are they perfect? No what is and addressing every wart costs money. What the design lets you do is combine multiple driver is away that very much acts like a single crossover less driver. For a given SPL It produces less harmonic distortion than the same drivers would if radiating individually. How much effort one puts into making that happen and how difficult that is, is at least partly related to the acoustic power you need to produce. What is not obvious is that a speaker like an SH-50 is AT LEAST 6 dB more powerful than a full size voice of the theater speaker and goes higher and lower.
Art is right too, I have not been able to get the company very interested in hifi . We don’t advertise much at all, we have never put a system out with any famous bands on tour. But by having a better product and allowing the venue owners and system designers to hear what a few of our Synergy horns can do side by side with the best and baddest the big companies can offer at any price, we have grown very significantly every year. In the last few months The Buffalo Bills, Boise State, LSU (the loudest stadium in the US) Nationwide arena as well as a good number of smaller college and high schools sports venues and large Churches have installed our Synergy horns.
Against that open green pasture, horn hifi appears to be a quirky market with a lot of Voodoo, horn folk lore and preconceptions. On the other hand, hifi is my hobby and it was Dick Heysers writing that made the idea of a single source in time and space loudspeaker interesting combined with an old friends comment, “there are speakers that sound goo, there are speaker that go loud but none that do both”, sounded like a target to me I thought.
Earl I have a pair of SM-60’s here in parts and have been slowly working on in my spare time, what would be an stock black ugly looking but very good measuring pair of speakers.
I would like to hear your speakers and want to talk to you about a crazy high intensity acoustics thing not a loudspeaker as well. I would like you to hear a Synergy horn too and see how they measure with your technique and see it’s nice impulse response. We hear with our ears not our measurements after all. After the middle of next month, things will be easing up at work and I should be able to get these put together by then so I will bring them up your way when I visit my brother.
Best,
Tom
Sorry, I don't understand at all.
What I can see or not depends on my vision and my glasses mostly?
As far as "strippers" I think I'd prefer to see them over hearing them... a joke. 😀
But seriously, if I get this at all, the amount of apparent closeness to the soundfield depends a great deal on the SPL level and the distortion (or lack thereof) of the speaker system, and not much else (assuming no strange room interactions or wild phase relationships between drivers or speakers).
I'm just curious as to what this effect actually is.
Hi, I'm a bear. Stuffed at that... apparently. 🙄
Does not the power density increase as one goes back to the apex of the horn when say the bass drivers are run increase, compared with the power density of the wave distributed at the mouth (and that wave going outwards to the audience)?
Myhrrhlein
You might be able to hear a .1dB change in level under the right conditions, but you can’t hear a .1dB change somewhere in a loudspeakers frequency response.
If you are in Synaudcon, or were, write Pat about that and also ask him about how the Synergy horns work. He has measured them, listened to them and installed them.
I suppose your right, they do not preserve time as the upper and lower limits have the phase response of each section.
What they don’t have is the phase shift / group delay between the frequency ranges like one would have with normal crossovers. In other words, the acoustic phase looks like a single broad band driver.
Best,
Tom
can someone show an impedance curve of a mid or a woofer loaded by synergy horn? space between speaker cone and walls of a horn must create resonant chamber, or there are ways to avoid that resonance?
That was my goal as well, but for home theater, not pro venues, although many of my speakers did make it into clubs and schools with some success.
"see it’s nice impulse response" - now there we are on the same page. The impulse response tells all (in all directions of course). If it is good then the system will produce good square waves, and the system will have a virtual "point source" spatial location. My speakers have the best impulse responses that I have seen (extremely compact, with little to no tails) - we can compare.
"We hear with our ears not our measurements after all." While this is obviously true on the surface it is seriously flawed in reality. No human is able to completely control his biases (read Kanneman if you don't agree with this statement). Since our hears are useless without our brains and our brains are incapable of unbiased judgments, I will bet on the measurements every time.
People come to like what they expect and they expect what they are used to - this mean that you like what you have come to like right or wrong. To get beyond this problem you have to listen to what is objectively "right" (calibrate to "good, if you will) and then you get used to something that is not flawed. When you do this then all this other junk that people rave about just sounds so bad that you simply cannot understand what they are thinking.
Yes, please, lets get together. I do all my measurements in my living room, which is quite large when its empty, but this setup is not a few minutes job. So some lead time would be nice.
Then you have a very dead room and it will sound that way. High directivity allows you to have a live - good acoustics - room with no early reflections. Directivity does matter.
Hi Tom,
Graci! 🙂
..was out for the week (..life intruding and all that.) 😀
I particularly like the BBQ track 2. 🙂
On a similar note:
Here is a small lab out of Princeton that's into generating cross-talk cancellation software (where more directive loudspeakers improve the result):
3D3A Lab at Princeton University
..and their index of speakers (thus far):
3D3A Lab at Princeton University
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There are some even better speakers in the future with people like Geddes and Danley working towards them. We probably all love this a bit stuff too much.(-:
Oh wow! Holy crap. I may have just had an official newbie dumbhead moment of speaker design enlightenment! What these gentlemen are saying is that *if* you have the phase thing worked out, you can trade in any over-excess-ridiculousness-abundance of headroom you may have in for whatever transfer function your heart desires *in the crossover*, therefore negating any ripple generated by the drivers or even minor crap sticking in or out of the horns like holes for example if they were actually creating ripple, because it all comes down to time anyway?? That can't be true????
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Yep, a good speaker can make a room sound as good as it can. We are slowly building a semi anechoic chamber in an extra bedroom to play with via foam were collecting. Guessing a 901 still won't make it sound like the Lascala Opera house (-:
Hi ,
Since the thread is about drawbacks , I have made one and took it casually sounded really off and the biggest drawback may be is ,
"Making them"
Luckily we make the drivers and crossover ourselves , but had to rework the learning curve on horn loudspeakers . Compression ratio to use phase plug or not , to use acoustic lens or not
with regard to attack and pronouncement of mid bass of Tabla (Indian classical music instrument)
It was as accurate as any other Hi - end midbass horns using very expensive drivers compared to the cost price of the drivers I used .
Suranjan
Since the thread is about drawbacks , I have made one and took it casually sounded really off and the biggest drawback may be is ,
"Making them"
Luckily we make the drivers and crossover ourselves , but had to rework the learning curve on horn loudspeakers . Compression ratio to use phase plug or not , to use acoustic lens or not
with regard to attack and pronouncement of mid bass of Tabla (Indian classical music instrument)
It was as accurate as any other Hi - end midbass horns using very expensive drivers compared to the cost price of the drivers I used .
Suranjan
Its not really. That's because some things can be EQ'd out and some cannot. Things that do not vary with position can be EQ'd with a global solution but things which differ at different points cannot be fixed with electronics. Fixing one point always makes the others worse. That's why looking at polar maps is so critical - to see what is correctable and what is not - or what has been corrected for say the axial response making everything else worse.
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Hi ,
Correct me if I am wrong , to summarize the synergy patent covers the process of making a horn with multiple entry point .
the patent does not cover the design "artistic design"
I am sure there are sane minds populated with ideas to make to take different approach to horns with multiple entry points , check out the revived popularity of Karlson horns after the -TH .
Suranjan
Correct me if I am wrong , to summarize the synergy patent covers the process of making a horn with multiple entry point .
the patent does not cover the design "artistic design"
I am sure there are sane minds populated with ideas to make to take different approach to horns with multiple entry points , check out the revived popularity of Karlson horns after the -TH .
Suranjan
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