I have no comments about it besides assuring that the company that state all of it does crap in term of Sound. Still, I find that the way in which they think about construction of the walls of their back-loaded horn worth very much attention. Take a look:  

(Free-Press-Release.com) June 23, 2009 -- Many commercially available loudspeakers are closed-box enclosures and bass-reflex enclosures. Reasonably-priced backloaded horn speakers are not many because of internal complicated structure. So, many audio nuts made that by oneself. However, Hasehiro Audio achieved a low price. Moreover, they succeeded to eliminate right-angled bend. (i.e., elimination of a hollow-gray sound)  You can get yearning exponential backloaded horn speakers at last. Let's be intoxicated by a beautiful curve makes authentic backloaded horn sound.

1. The First Concrete Horn By Mr.Imanari:
- In about 1975, Mr.Imanari (Audio nut and director of invention school) introduced own invention at the floor.
- That's the first concrete backloaded horn speaker. - cubed concrete, 10cm unit and 2.5m long backloaded horn.
- Hasehiro requested the production to Mr.Imanari momentarily.
- After that, he got some orders by mouth-to-mouth advertising.
- But they take up to over 1 year from ordering to reception because he was hung up on new invention.
- As a result, it went of mind of audio nuts by little and little.

2. Batonpassing:
- In about 3 years after completion the first concrete backloaded horn speaker, Hasehiro thought - this is so wasteful that it has a tremendous amount of potential and anyone think of nothing to concrete backloaded horn and the making. - Hasehiro told his long-held aspiration to Mr.Imanari and he made a promise the tool passing and initiation of the technical know-how.
- But before that, Mr.Imanari was taken with illness and passed away after several months in a hospital.
- His heart swelled with put that out into the market for answer to the will of Mr.Imanari.
- Hasehiro told the antemortem promise to the bereaved family, and he received some undisposed tools from them.
- Hasehiro made trial model over and over imagining the making process from the tools.

3. Study From Fabric:
- Concrete characteristic vibration harden the tone color.
- So first, Hasehiro was starting to amelioration of concrete fabric.
- He changed black cement to white cement and also he changed aggregate and mixed in particular absorb sound chips.
- As a result, Hasehiro succeeded to remove concrete-specific sound character and could get the fabric know-how.

4. Pronouncement:
- In 1990, Hasehiro Audio submitted the model "AX" (discontinued) used 12cm unit to The International Housewares Show.
- After that, Hasehiro Audio submitted the succession model "HoPe-twoBx" (discontinued) used 16cm unit to the exhibition and they receive orders from after too.

5. Challenge To Double-Layered Structure:
- Hasehiro had wondered for a long time making the upper grade model used 20cm unit.
- But it looks about 50kg from specific gravity of concrete.
- So, it is difficult to distribute and had to give up.
- However, one audio nut suggested the double-layered structure of wood and concrete for not only weight saving but also think it should be a natural sound more add to wood sounding.
- Hasehiro had a lot of trouble. - cracks in the concrete when drying etc.
- But Hasehiro could resolve that for technical guidance from Onoda Cement Co., Ltd.
- In 1997, completed the world's first backroad double-layered horn speaker. - WCW-200A (discontinued)

6. Wood with Concrete Horn:
- That's a fusion with Japanese cement technology.
- WCW series is the backloaded horn speakers of double-layered structure. - implant concrete horn directly into wooden enclosure.
- WCW series reproduces unbelievingly clear and realistic sound. - controls resonance by wonderful integration of wood and concrete.
- Concrete horn of high radiation efficiency. - profound low tone and margin of high efficiency.
- That's not mere loudspeakers anymore.
- That's the exact live reappearance equipments.
- WCW series gold titled in eliminate tube amp category of The Vacuum Tube Audio Fair in Akihabara from 1998 to 2000, 2002 and 2003 (From 2004, no elimination races)

That's "Hasehiro Premium"

decoud wrote:

One of the problems with horns is the inflexibility of frequency cut-off: you are limited to a discrete number equal to the number of horns you have. This makes experimentation difficult without having an absurdly large array of different horn sizes to try. So how about the following configuration: The entire loudspeaker is a single profile that changes continuously in cross section from floor to ceiling with high frequencies being in the centre and low at the extremes. Any cut-off frequency is therefore always available (in two positions): it is simply a matter of driver positioning. Equally, the only limit on the number of "horns" is the number of drivers. Removable horizontal septations can be introduced if necessary but it would be nice to do without them. Once the optimal profile is determined the thing would be trivial to build: it could be just a series of CNC'd slabs of mdf stacked on top of each other. Rgds, d

What you have there is Tom Danley's Unity Summation device in principle. Tom has a predictable method that limits the trial and error approach. It would be very difficult to get the frequency response flat for your example. The distance between the drivers is too great and will result in a lot of phase and timing problems.

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….