Too bad the efficiency level was too high to include some more waveguide designs. The measurements provide some very interesting issues. I am interested in what would happen if there were some designed that did not use compression drivers were in the shootout.
Hey, no "minimum phase horn"
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I agree, but we may be alone in that.
Nom de Dieu c'est triste Orly, le dimanche
Don't worry, the "dimanche" and the rest of the year too.
Hello Panomaniac
It will be very presumptuous of me to say I know why, but I may try to throw few hypothesis.
Apart of the fact that the crossover ferquency was probably to low for many horns:
1) The listening room was very large (it is a kind of ballroom) and the seats was very far from the petite Onken enclosures + horn. Also the Onken bass enclosure with the horn on top was placed on a stage, see:
http://www.melaudia.net/zfoto/etf10/concours/IMG_4309-800x533.jpg
The axis of the horns were also quite high above the heads of the listeners.
So it is not surpising for me that the horns that won were horns having been used in movie theaters.
2) it is difficult to associate the horns having the best pulse response and the best spectrograms with bass reflex having quite poor impulse response. The ideal will be to mary them with bass horns.
3) in the conditions of the listening, in the far field in a semi-reverberating room, the level of the reverberated energy is large compared to the level of the direct wave and the benefit of an excellent pulse response is null. (Even in proximity I know people that prefer a pulse response with many effects of HOMs, diffractions, reflections because it add some blurr those people feel comfortable).
4) The horns having an increasing directivity with frequency should be listen in proximity and on axis (or near the axis). For those horns, in such large room the tonal balance change when you move from a seat on axis to a lateral seat.
5) this was not a blind shoot-out and the visual appearance had its importance (during the shoot out when the contest was between B : Bill Wood's beautiful AH300conical horn and A: the Musique Concrete J321 Le Cléac'h round black horn, before we even play music, one guy shouted: "B" and the crowd to laugh...). Also famous brands were favorite even before to start the contest. And as there was a majority of German people in the audience, I guess that explain why 2 Klangfilms horns were in the final... (IMHO one of them was far better than the other one which should not have been in final if the shoot out was blind).
But there is something most of ETF2010 participants will accord on: in the 1/8th final, the 8 winner horns were good horns.
Best regards from Paris,
Jean-Michel Le Cléac'h
It will be very presumptuous of me to say I know why, but I may try to throw few hypothesis.
Apart of the fact that the crossover ferquency was probably to low for many horns:
1) The listening room was very large (it is a kind of ballroom) and the seats was very far from the petite Onken enclosures + horn. Also the Onken bass enclosure with the horn on top was placed on a stage, see:
http://www.melaudia.net/zfoto/etf10/concours/IMG_4309-800x533.jpg
The axis of the horns were also quite high above the heads of the listeners.
So it is not surpising for me that the horns that won were horns having been used in movie theaters.
2) it is difficult to associate the horns having the best pulse response and the best spectrograms with bass reflex having quite poor impulse response. The ideal will be to mary them with bass horns.
3) in the conditions of the listening, in the far field in a semi-reverberating room, the level of the reverberated energy is large compared to the level of the direct wave and the benefit of an excellent pulse response is null. (Even in proximity I know people that prefer a pulse response with many effects of HOMs, diffractions, reflections because it add some blurr those people feel comfortable).
4) The horns having an increasing directivity with frequency should be listen in proximity and on axis (or near the axis). For those horns, in such large room the tonal balance change when you move from a seat on axis to a lateral seat.
5) this was not a blind shoot-out and the visual appearance had its importance (during the shoot out when the contest was between B : Bill Wood's beautiful AH300conical horn and A: the Musique Concrete J321 Le Cléac'h round black horn, before we even play music, one guy shouted: "B" and the crowd to laugh...). Also famous brands were favorite even before to start the contest. And as there was a majority of German people in the audience, I guess that explain why 2 Klangfilms horns were in the final... (IMHO one of them was far better than the other one which should not have been in final if the shoot out was blind).
But there is something most of ETF2010 participants will accord on: in the 1/8th final, the 8 winner horns were good horns.
Best regards from Paris,
Jean-Michel Le Cléac'h
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Thanks Jean-Michel, very well explained. Sighted tests can be tricky, but they don't always trump hearing. Brand loyalty and nationality can be harder to overcome.
Your point #2 is well taken and leads to a rather complex subject - driver matching. Some drivers just play together better than others, despite similar FR. Something about the tonality and maybe the decay. But that's a big subject and for another thread.
Your point #2 is well taken and leads to a rather complex subject - driver matching. Some drivers just play together better than others, despite similar FR. Something about the tonality and maybe the decay. But that's a big subject and for another thread.
Besides all imperfections of that shootout (XO parameters, brand loyalty and nationality, general setting) - what is your impression on the acoustic lens regarding a specific sonic pattern (not directivity related!) ?
Michael
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In my opinion, the most interesting case is the conical horn.
I think, the less amount of reflected wave from mouth to throat result to flat or rectilinear geometry because it's more directive than curvilinear geometry.
So, I think there are less reflection in-axis but not off-axis, compared to curvilinear shape which is more omnidirectional reflection surface.
I think, the less amount of reflected wave from mouth to throat result to flat or rectilinear geometry because it's more directive than curvilinear geometry.
So, I think there are less reflection in-axis but not off-axis, compared to curvilinear shape which is more omnidirectional reflection surface.
Hello Michael,
I really liked the Klangfilm horn with its acoustic lens at mouth and the field coil driver (IMHO it was superior sonically than, the other Klangfilm without lens and with an alnico driver).
During the listening of that Klangfilm horn equipped with the acoustic lens at mouth and the field coil driver I felt that the sound was smooth an delicate (romantic?) but also that there was some loss of details compared to the Avant-Garde horn or the Le Cléac'h.
I guess that the numerous diffraction that we can see on the spectrogram add some blurr to the music and erase some details that can be perceived as non useful for the perceiption of the music.
What I can see on the spectrogram of that Klangfilm is that it has an even repartition of numerous effects of diffraction, reflection, HOMs... , both on a very large duration and until the highest frequencies, when, others have a pattern with concentrated zones in time and frequency.
There is probably some masking effect (masking effect by "noise") at work that in this case is not prejudiciable to the perceiption of the music.
Best regards from Paris, France
Jean-Michel Le Cléac'h
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Hello JoMoCo,
Last year in ETF2009 the system brought by Melaudia for the shoot out of 30 single-end output transformers was equipped with a Westrex Acoustilens. See:
http://www.melaudia.net/zfoto/etf09/steph/P1010536.JPG
I found myself that this system was not the most accurate to judge output transformers and for sure an important part of the loss of details was IMHO due to the lens (and also to the truncated mouth).
I make some difference (and for sure I am not the only one) between horns dedicated to the fidelity of the information in the record (on which bad records sound bad) and horns dedicated to deliver whatever is the quality of the record a comfortable sound even if fidelity suffers.
For me the Acoustilens belongs to the second category.
Best regards from Paris, France
Jean-Michel Le Cléac'h
Last year in ETF2009 the system brought by Melaudia for the shoot out of 30 single-end output transformers was equipped with a Westrex Acoustilens. See:
http://www.melaudia.net/zfoto/etf09/steph/P1010536.JPG
I found myself that this system was not the most accurate to judge output transformers and for sure an important part of the loss of details was IMHO due to the lens (and also to the truncated mouth).
I make some difference (and for sure I am not the only one) between horns dedicated to the fidelity of the information in the record (on which bad records sound bad) and horns dedicated to deliver whatever is the quality of the record a comfortable sound even if fidelity suffers.
For me the Acoustilens belongs to the second category.
Best regards from Paris, France
Jean-Michel Le Cléac'h
thanx for your impressions regarding those acoustic lenses, Jean-Michel.
Looking at how these are actually made one can only be surprised that they do not completely destroy horn functionality.
http://klangfilm.free.fr/index.php?.../loudspeakers/acoustic_lenses/kl-lz303/&num=1
Backside view at lower right corner:
For sure they also shift vertical directivity unintentionally ...
Michael
Looking at how these are actually made one can only be surprised that they do not completely destroy horn functionality.
http://klangfilm.free.fr/index.php?.../loudspeakers/acoustic_lenses/kl-lz303/&num=1
Backside view at lower right corner:
For sure they also shift vertical directivity unintentionally ...
Michael
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When I read all of it I came to the impression that most of the differences in subjective preference resulted in the driver - irrespective of the acoustic coupling.
This isn't really surprising considered it was all done in mono.
I think it would be instructive if next time they took last years (this year) winners in subjective and objective performance and compared them on the same (or very similar) objectively superior horn.
This isn't really surprising considered it was all done in mono.
I think it would be instructive if next time they took last years (this year) winners in subjective and objective performance and compared them on the same (or very similar) objectively superior horn.
???
Why you think ?
- I mean - a lot of performance issues of horns are most clearly related to "timing / echo / smear" and this shows up in mono as well as in stereo presentation.
On the other hand - right now there is some hype on field coil and ALNICO that may bias results easily, no ?
Michael
In mono, a spatial presentation has a lot more to due with driver damping (or lack thereof). It's no longer about head-shading and Inter-aural level and time delay.
With regard to damping. The single biggest difference is the fatigue of the driver suspension in the older drivers (and also fatigue of the diaphragm itself, though they are often integrated). The motor comes in second.
Freq. imbalances play their part initially, but over a fairly short period people can adjust to those differences. The same is true with moderate differences in the overall radiation profile (..largely a function of the waveguide/horn), particularly when not in stereo.
With regard to damping. The single biggest difference is the fatigue of the driver suspension in the older drivers (and also fatigue of the diaphragm itself, though they are often integrated). The motor comes in second.
Freq. imbalances play their part initially, but over a fairly short period people can adjust to those differences. The same is true with moderate differences in the overall radiation profile (..largely a function of the waveguide/horn), particularly when not in stereo.
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This is a new concept to me.
Whats "driver dampening" ? - I mean - we see the imperfections of the total system (horn + driver) in the IR - and even better in the t/f spectrogram, why do you distinguish between driver and horn contribution here ?? - and what is "dampening fatigue" ??? - change in Qm ???? - burn in ?????
You know I'm not questioning that each and every difference has its contribution to the overall sound pattern, but this does not explain to me why you think driver performance is rather dominating in mono than in stereo.
Michael
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Damping in this context relates to driver compliance at *extremely* low excursion levels (..and with a compression driver this includes the resistance from the phase-plug). It also refers to the diaphragm's modal and bending wave behavior, and its relationship with its surround.
Lower level (spl) details often have information about what we tend to describe as "air", "space", "depth", and even image "solidity".
Over-damp the driver and you start to incur "signal loss" - altering these characteristics and often largely loosing them.
Of course most drivers also make *additions* to the signal, even to the point of accentuating some of these characteristics, along with creating a truly "noisier" signal. (..note that accentuation of desirable traits is usually preferred, additional perceived noise is not.)
If you take the effects of stereo out of the "equation", effects that provide similar properties (though are more concerned with lateral effects), then you are largely left with the driver's contribution.
Oh, and the reason you don't "hear" more about this is because most people really don't know about it..
Though not about compression drivers, you could read the "conversation" I had with Taperwood on this subject at post 15 through 20 here:
http://www.diyaudio.com/forums/full-range/75940-my-fostex-fe-108ez-project-part-2-a-2.html
Lower level (spl) details often have information about what we tend to describe as "air", "space", "depth", and even image "solidity".
Over-damp the driver and you start to incur "signal loss" - altering these characteristics and often largely loosing them.
Of course most drivers also make *additions* to the signal, even to the point of accentuating some of these characteristics, along with creating a truly "noisier" signal. (..note that accentuation of desirable traits is usually preferred, additional perceived noise is not.)
If you take the effects of stereo out of the "equation", effects that provide similar properties (though are more concerned with lateral effects), then you are largely left with the driver's contribution.
Oh, and the reason you don't "hear" more about this is because most people really don't know about it..
Though not about compression drivers, you could read the "conversation" I had with Taperwood on this subject at post 15 through 20 here:
http://www.diyaudio.com/forums/full-range/75940-my-fostex-fe-108ez-project-part-2-a-2.html
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What I would look at are the CSDs within the first 0.3ms or so. Normally when you have a mixture of honk spread out, you cannot identify concentrated honk, thus subjectively it's more pleasing. This is the same with any driver/speaker. If you look at CSD in terms of periods, the better drivers will have an even decay. Now, if the contestants had filters to optimize performance, the story might have been different.
I've been looking through the pictures of the shootout, although the room seems big, the ceiling is not so high, and I assume measurements are taken at the hight they are listened to. With this in mind, it seems room reflection is coming in around 3ms. I was wondering why all the horns had this about the same location. The measurement report says it's reflection due to lip to throat distance, but I still wonder whether it might be also the same as floor reflection. It would seem No. 10 has very little of it might possibly be due to directivity pattern.
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