Hi all
One of the posters suggest I comment on the thread, so a few words.
The design may appear puzzling but there is a reason for the layout.
The object is to produce the radiation of a single wide band driver and have a high degree of directivity and to have that directivity be as constant as possible.
In no order, the reason why the hf driver being behind the mids and the mids behind the woofers is because the hf portion emerges from a crossover first and the lf last.
In normal speakers, even ones called “time coherent” there is a phase shift going from below xover to above xover, they have an “all pass” phase rotation which is also a change in time.
This would be true of all the familiar named types like Butterworth, Linkwitz and so on, they all have a rotation (above 1st order) which adds 90 degrees of shift per order so a 4th order exhibits a 360 degree phase rotation from well above to well below Xover F.
It is that phase shift or the change in time vs frequency which prevents most multi-way speakers from producing a square wave over a broad bandwidth.
We don’t listen to square waves but they are a good diagnostic signal and there reason they can do this has nothing to do with square waves.
If you have two drivers and place them a quarter wavelength or less apart, they add coherently into one source and they feel each others radiation resistance. This condition of coherent addition is easy for woofers where the wavelength is large compared to the source.
If the two sources are significantly farther apart, say a half wavelength or more, then they radiate as independent sources instead of adding coherently and now produce an interference pattern which is a pattern of addition and cancelations evident in a polar pattern as lobes and nulls. The greater the driver spacing, the more lobes and nulls are produced.
When one has a crossover, there is a region where both sources radiate simultaneously and so fall into this regime. In “hifi” loudspeakers the idea is to make the main or largest lobe face the listener and the nulls and other lobes point elsewhere.
As one Goal in the synergy horn is to have a high degree of directivty and have it be constant, one cannot have an interference pattern and do this. For the drivers to add within a synergy horn, they are always less than a quarter wavelength apart when they interact or where multiple drivers are interacting (such as 4 mids and 2 woofers in the SH-50).
By doing this and having ht e correct phase response from the crossovers, the drivers sum together into one system so well that you can remove the grill (mine don’t have grills, but I like the look of horns) and not hear it’s a three way speaker, you can walk up and never hear there is more than one driver, even when your head is fully inside the horn mouth.
That coherent addition is the object, there are no lobes and nulls, only one large forward lobe that in time AND space appear to be a single driver.
Being able to preserve time well enough to produce a square wave was simply a side effect, not the object. By radiating as a single segment of a point source instead of an interference pattern, the speaker conveys less information about itself so far as where it is in depth when your eyes are closed in a home stereo .
In larger sound installations where most of our stuff goes, there are several advantages over the arrays normally used. First, there is still only one arrival in time instead of a arrival from each source according to distance from the microphone so the sound is vastly more hifi. Second with an interfering array, the frequency response is different at every location and if the wind blows at all, the interference pattern is quite obvious.
The up side of those large arrays is they require a lot more drivers when they partly cancel each other out instead of adding coherently and of course more amplifiers, processors and so on all good for the manufacturers.
The up side of the Synergy horn is even though they are much smaller, without the inference pattern, there is far less energy radiated to the sides, rear, up and down and this is great for sound large rooms.
So far as crossover design, there is no number one rule, there are lots of rules which apply and while a thumb rule might tell the DIY’r how to place them, what matters is if they interfere with each other. Part of the reason they are large is for power handling and part because they are not a normal topology but a a filter design which accommodates the amplitude and phase of each range to add into one source.
I have to apologize for our web site and the old measurements, since the web firm went under we have not been able to update anything and our new website is not quite done. The goal was to have it done before the Trade show next week but even that may not happen (I don’t know beans about that html stuff). Since last year we have also been about as busy as we can be.
To offset the stymied web page they set up a Facebook page which has FAR more current stuff.
http://www.facebook.com/DanleySoundLabs?ref=tsOne of the things we have done in the development of the synergy horns was to adapt an old time subjective evaluation, the generation loss test. In the old days of analogue tape, one would record music and then see how many generations it would take before sounding bad.
Any part of the modern reproduction chain can have a signal passed through it multiple times before it becomes unlistenable, any part except the loudspeaker. When you use a measurement mic to record a loudspeaker (we did it while up in the air) you find some speakers sound bad on the first generation (some just listening through a mic), very few sound ok at two generations and very very few will go three generations and at three or four even an SH-50 is sounding lame.
AS the Synergy horns got closer and closer to one source in time and space, they also would allow more generations before sounding bad.
While I can’t demonstrate them to you and the company isn’t interested in home hifi at the moment, if you have headphones, you can hear what a couple of them sound like.
The first outdoor test of the J1, here how little the sound changes as the camera man moves around
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http://www.youtube.com/watch?v=pk54IFD4znw&feature=fvwrelThis is the J3, a demo in December for some stadium sound people. The video was taken by a guy who attended (his mics were squashed when too close to the sub). This was pretty loud, adjust the volume to scale the voice at 1:30. Most of the people were out in the field on a ridge at 450 feet (at 2:15 he pans out). Notice how there is no comb filtering as he moves and how much directivity there is when he walks under the flown cabinet.
http://www.youtube.com/watch?v=5MOG_sPejGA&feature=relatedWhat you can do with one
http://www.audioprointernational.com/news/read/danley-jericho-horns-cover-30-000-capacity-florida-football-stadium/03934It had to happen, someone using two of them indoors for a stereo;
http://www.fohonline.com/news/6814-soundco-takes-pair-of-danley-jericho-horns-inside-for-church-project.htmlWhat that sounds like
http://vimeo.com/40148645Some history
http://www.avnetwork.com/features/0014/epiphany/77186Its nice when even the players notice;
http://www.youtube.com/watch?v=4CsS91hTKqwAnyway, I hope the ramble helps explain what’s going on and what’s different.
Best,
Tom Danley
Danley Sound Labs
