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In the Forum: Horn-Loaded Speakers
In the Thread: The absolutely “best” material for horns construction.

Post Subject: I'm not trying to promote the SynergyPosted by JLH on: 8/19/2009

First let me say I am NOT trying to promote the Synergy horn. I just think it is very intresting to look at and to think about.

Ideal loading only occurs at a singular frequency within any horn. This ideal loading point is where the length is 1/2 a wavelength and the circumference is equal to 1 full wavelength. Since the acoustic size of the wavefront is exact in relation to the horn, ideal loading occurs. Any frequency above or below this is not being loaded in an ideal way. Therefore, there is not a horn that exists that can achieve ideal loading across the horn’s whole bandwidth. In addition, there is no such thing as the perfect driver for a horn. There is only a singular frequency point there a driver will be perfect for the horn it is mounted to. (I'm not discussing Tone, just loading) All drivers mounted into all horns are compromises as soon as they play any frequency that is not exact fitting. So, to me the whole ideal loading thing is a moot point.

I do not believe you fully understand what Danley is doing with the Synergy horn. Each driver is loaded in the most idea way with the least amount of compromises. A curved wall horn holds the same flare rate throughout its entire length, a conical horn does not. The reason why Danley uses a conical horn is its variable flare rate nature. At the apex (throat) of the horn, the flare rate is fast. As you progress closer to the mouth, the flare rate decreases. This high flare rate at the apex (throat) is ideal for loading the compression driver. The mids are mounted further down the horn where the flare rate is appropriately slower for their operation and this continues for the lows.

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.

Each driver injects into the horn where the most ideal loading should occur. This also leads to the minimal phase nature of the Synergy horns. This makes the Synergy less of a compromise than a multi horn stack. I understand your underlying feelings about a multi driver horn like the Synergy. I too felt like everything we know about horn purity is being violated. 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.

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