Synergy Horn probabilities?

[speakrsrfun]

I currently have a dipole line source as my main stereo pair consisting of 9 Silver flute 5.5" and 6 BG Neo8s per side. I use two 12" loaded 18Hz Tapped horns for bottom end re-enforcement. I like the sound of this setup but have been toying around with the idea of using the Neo8s, Silver Flutes and a CD in a Synergy horn. Mind you I know very little about the theory behind the SH I find the concept appealing.

Now for a few questions... I've read through many threads on here regarding Synergy type horns but would like a bit more in depth theory into the design process. Is there a site out there with this sort of info within it?

What would the probability be of using a CD, 4 Neo8s and 8 silver flutes per side and getting a decent result.

EDIT: I'd like these to cover from 80hz to 20kHz and max size would be no more than 24" square.

Would the Neo8s be a viable option if a rear chamber was used to seal off the mids?

Would I be better off replacing the Silver Flutes with a pair of 8" pro midwoofers per side.

I've been building speakers for 27 years and things have gone dry a bit for me, I need a pick me up to get my juices flowing again. I HAVEN'T BUILT A SINGLE SPEAKER IN OVER TWO YEARS MAN!

Any info or points in the right direction would be greatly appreciated.

 

[bwaslo]

I don't think the Neo8s will do so well in a Synergy -- getting them to compression drive into a small aperture (needs to be small and near the tweeter aperture) will work. Can't think of a way to even approximately equalize the path lengths across the panel to the aperture, while keeping that path delay short. I don't know if there would be any good reason to use a panel driver there, either? Small, sealed-back cones are the way to do this IMHO.

For best tech info about Synergy, look up Tom Danley's patents on google. But note that not all the features (or requrements) in the patents are actually used in the commercial Synergy horns.

And of course the 24"x24" horn would only really be a horn down to about 400Hz or so. Not that that would be a show-stopper, but from 80Hz to 400Hz it would basically just be a box with the drivers concentric around the horn throat.

 

[natehansen66]

Like Bill says to do a true Synergy the size of the Neo8 is all wrong. You could, however, build a conical horn just for the Neo8S and I think it could work quite well down to the pattern loss of a 24" horn. I built some horns and posted it here: http://www.diyaudio.com/forums/planars-exotics/276959-rediculously-large-neo-8-horn.html

What I don't show in that thread is that I also built a large conical horn for the Neo8 and with some changes could work quite well down to 300-400hz. I think the S model would be even better.

 

[CLS]

Here is a concept drawing in the patent:

http://patentimages.storage.googleapis.com/US8284976B2/US08284976-20121009-D00006.png

So it's not necessary a 'horn' (or waveguide) with 'traditional compression driver' to be a 'Synergy'.

It's kind of a mega coaxial system with discrete elements. A constant directivity is realized by the sizes and relative positions of all those elements.

 

[natehansen66]

Yeah, I suppose it depends on the bandwidth of the mids. The concept calls for the mids to enter at a certain cross sectional area of the horn which is determined by the upper end of the mid response that's desired. With the Neo8S I think you could skip the mid altogether and just add the woofers where you could then position them correctly.

 

[djk]

"And of course the 24"x24" horn would only really be a horn down to about 400Hz or so."

http://i56.photobucket.com/albums/g196/dkleitsch/12PE32x2_zpsbe9adcef.jpg

22.6" square (57.5cm square) = 3300cm^2

A 24" square horn with a 90°x 90° design will have no pattern control below 300hz or so.

I built some 24" square 90°x 60° horns (with the MantaRay break) in 1981 and they had a bump at 200hz and they dropped like a rock below there. They had a 3"x 13" throat and were flat to 800hz with an inexpensive 15" driver.