decoud wrote:

Perhaps I misunderstand the unity horn, but I did not mean my suggestion to depend on summation: the idea simply is that one horn flows directly into the other, rather than being discrete; you could have the bottom or top half alone. So the profile is still tractrix (say) it is just that it merges smoothly into its neighbour. The drivers need not be any further apart than they are in a conventional horn system configuration. Would that not work?

It does matter how you want to intellectually dissect your example, it is in principle still a summation device. In order to get a flat frequency and phase response, the output from each driver must sum correctly at their crossover point. Your example only differs from the unity horn in the driver locations. There will not be anything approaching continuity between the drivers because they are multiples of wave lengths apart at their perspective crossover points.

John, I have to confess that I feel very not easy about the idea of Synergy horn. I did not hear the Danley Synergy horns and I have very superficial understanding of what he is trying to do with the whole Synergy/Unity idea. The whole idea does not make very horny, pun intended….

One of the theoretical premises of my understanding of horn loading is for any given loading application there is an infinitely-small bandwidth of “ideal loading”. The “ideal loading” is not a field but rather a single point similar to antiskating with pivoted tonearms. A perfectly balance antiscating is a single point on the records, everywhere else are just acceptable compromises.  The same is with horns. I given single frequency has own “perfect horn” with max horn EQ, minimum acoustic low-passing and best possible other characteristics. A deviation from this “perfect narrow frequency” makes acceptable compromises.  It does not mean that a horn cannot serve 5-6 octaves but the level of acceptable compromises becomes a bit wider as the driver at lower knew stops acknowledge the horn and at higher knee become too much restricted by the horn size. Again, not saying that it is unusable but I am just explaining the concept.

Not let look at the Synergy design. Let leave aside the way how Mrr. Danley proposes to integrate the drivers and let look at the Synergy idea only from a perspective of best horn for a best given driver. We would see that the mid drivers in Synergy might have own “best” lording but the high and low drivers do not. The LF driver looks like loaded into an insufficient re-entry horn and the HF drivers see also very far from optimum horn. Is it a too high price to pay for point source, particularly considering that I do not support  the notion that a point source is necessary better than 3D source?

JLH wrote:

I do not believe you fully understand what Danley is doing with the Synergy horn.

Nope, I do not. Well, I understand it but I am not willing to acknowledge that I understand it as the Synergy horn idea looks too freakish to me. You do not see me arguing the Synergy idea I just feel no interest. I might feel an interest in the Danley’s creatively but to me the even to look at the Synergy horn is scare.

JLH wrote:

Real world example of the flare rates inside of Danley SH-50: the SH-50 is a 50 degree conical horn. The mids tap into the horn at around 2.78 inches. The distance from the compression driver’s diaphragm to the mid tap point totals 3.66 inches. The area of expansion is from 0.24 square inches to 11.29 square inches. This equates to a flare rate of 1132Hz loading the compression driver. The electrical crossover is around 1200Hz, so the compression driver is operating within a very ideal way. Since the wavelengths within the compression driver’s range are acoustical small in relation to the rest of the horn, it’s sound is not harmed by the rest of the horn. The same is true for the mids and lows. I have ran through the math it all adds up.

Are you sure that the same is for the mids and lows?  Do not take to account the fact that within the 5.56 inches the mids work as a re-entry path.  Also, I do not know how you can talk about math. Any geometry implies distance and distance implies two measuring points. In case of horn if we do not consider the re-entry paths then we have only two absolute points of distance: throat and mouth. We have a curve between them but it is not important. So, I we have a driver sitting on axes then we have a relation between the distances as the driver axes is the same as the horn axes and the driver’s exit points are equidistant to the mouth’s distances. How we have a driver that sits in the mid of the horn, with an angle of 50 degree to the horn axis.  The driver has own dimensions, let say 4” diameters of cone. So, what the hell would be “geometry” in case of this application. We have 4” smudge that describes the arrival time from the driver to the edge of the horn, then we have the re-entry reflections that smear the “distances” and “geometry” even more. I do admit that I might not understand something but I just too afraid to look in the theory of the Synergy deeper as I begin to ask myself questions that I have no answers. For instance you say that “electrical crossover is around 1200Hz, so the compression driver is operating within a very ideal way”. Ok, is it a crossover of 64dB per octave? If not then will the Synergy idea to choke with innermodulations?

JLH wrote:

However, Danley’s careful choices have resulted in a very well designed, measured, and sounding horn. I cannot argue with what my ears heard. In the end I did not believe that it is worth arguing about a horn just because its design features do not mesh well with our preconceived notions. We should just let things be the way they are and take them for what they are. I find the Synergy very intriguing. It does a lot of things very well. Would I use it in my own audio? Probably not because it is too clean and hi-fi sounding for my taste. I like my horn colorations too well. Should DIY people try to make their own Synergy? No-it is too complicated and cost too much.

Well, if what you say is true, even if I do not understand it, then perhaps there is no need to argue with Synergy idea but rather to heir Danley to built a set of Synergy system that would have more advanced demands then PA systems, dunk rock-n-roll punks and QSC Audio amplification.  If Dan Danley feel that his Synergy is potent to do good sound then it would be interested if he come up with home-targeted products, with “expensive” drivers and upscale demand for sound. It might be not his cap of tea (and I would not blame him) but since the proof is in a pudding it is very unlikely that a listening session in Guitar Center would pick my interest. Do you know if he does custom work? It is not something that I am interested but someone might find it worth to investigate….