Ever since hearing the custom designed Synergy Horns used by Soundstorm Pro at Esoteric Festival in Australia, I've been curious about them. More recently I have read multiple build logs of various interpretations, most recently the MEH design - which at some point I'd love to make when my budget is permitting, in the meantime I was hoping to design a more budget friendly option using the Synergy Calc V5 - but I've ran into some knowledge gaps and I can't find clear answers from the documents I have read so far.
I have several questions about Synergy Horns, specifically related to the Synergy Calc V5:
Thanks very much.
Andrew
I have several questions about Synergy Horns, specifically related to the Synergy Calc V5:
- The choice of compression driver is referenced vaguely, specifically the Celestion CDX1-1445, without explanation. Why is this driver chosen? Or more broadly, what makes a particular CD optimal for use in a SynergyHorn.
- The Compression Driver is not included in HornResp modeling, only the midrange and woofer. Why is this, and how does the performance of the compression driver change with the Horn Dimensions, impacting the overall design?
- In modeling the performance of the midrange driver, I adjust the horn shape to optimize its frequency response. However, when optimizing the woofer, it disrupts the midrange settings. What might I be missing in this process?
- Is a flared adaptor necessary for fitting the compression driver to the Horn Mouth, or is directly mounting it sufficient?
- The documents mention the distance of the Midrange Expansion Ports in the horn but lack detail on determining the best distance from the throat. What calculation or principle should be used? Is it within 1/4 wavelength of the crossover frequency of the CD? for example if the CD was crossed at 1000hz, it would be 90mm?
- How do you determine the position and size of the port opening? For example, once I know how far it will be from the throat, how do I determine the position of the port relative to the driver, as I see it's most often offset and not centered in the middle of the driver position? And then the size of the port?
- Most designs use a rectangular expansion port for the Woofer instead of a circular one. Why is this?
- Does rounding or flaring the expansion ports enhance horn performance?
- The calculator includes a section on maintaining directivity over low/mid frequencies. Why would one want to maintain directivity beyond natural effects, especially in near field applications?
Thanks very much.
Andrew
1. It doesn't matter what you use but you really
Won't know what you got before you put the compression driver in the horn.
2. Like above the horn for most part controls the frequency response of the cd.
3. You must juggle good luck.
4. You need the transition from cd to horn to be as smooth as possible.
5. As close as possible.
6. Yes offset as close as possible to cd.
7. Easier to build
8. Don't remember but I would assume so.
9. Maintaining directivity means all reflections are lessened = better imo some disagree.
Won't know what you got before you put the compression driver in the horn.
2. Like above the horn for most part controls the frequency response of the cd.
3. You must juggle good luck.
4. You need the transition from cd to horn to be as smooth as possible.
5. As close as possible.
6. Yes offset as close as possible to cd.
7. Easier to build
8. Don't remember but I would assume so.
9. Maintaining directivity means all reflections are lessened = better imo some disagree.
Hi there Amcgillbrown - good to see more Aussies getting into things!
I assume you're in Melbourne if you went to ESO?
In regards to the questions, they were pretty well covered by Momo, one thing I will state is when it comes to compression drivers I would highly recommend the dual diaphragm BMS or B&C units if you're after the linear phase characteristics of the proper ones...
Feel free to pm if you have more questions
I assume you're in Melbourne if you went to ESO?
In regards to the questions, they were pretty well covered by Momo, one thing I will state is when it comes to compression drivers I would highly recommend the dual diaphragm BMS or B&C units if you're after the linear phase characteristics of the proper ones...
Feel free to pm if you have more questions
Hey Gtimes!
Yep, Kiwi based in Melbourne - built a couple of subwoofers using the CSS 12" subwoofers, keen to get into more builds.
I'm sure I'll have more questions as I continue trying to understand it all deeper, thanks for your kind offer of help!
Are you based in Melbourne too?
Yep, Kiwi based in Melbourne - built a couple of subwoofers using the CSS 12" subwoofers, keen to get into more builds.
I'm sure I'll have more questions as I continue trying to understand it all deeper, thanks for your kind offer of help!
Are you based in Melbourne too?
That's cheating and exactly what I did bms 4594he + b&c 4x8s I forget model number. Now I would just 3d print one of the various horns on this site.
I'd argue it's not cheating, and certainly the exact synergy AMC is referring to uses the BMS, so in this context it's quite accurate 😉.
Interestingly the construction of the coax drivers is essentially a miniature synergy horn in itself. This is especially apparent with the cutaway of the B&C driver, where you can see the apex of the horn (hf) and the taps further down the throat (m/hf).
For most folks building a synergy of this cake would be near impossible.
Interestingly the construction of the coax drivers is essentially a miniature synergy horn in itself. This is especially apparent with the cutaway of the B&C driver, where you can see the apex of the horn (hf) and the taps further down the throat (m/hf).
For most folks building a synergy of this cake would be near impossible.
Those big $$$ coaxial compression drivers defeat the whole purpose of doing a Synergy type build.
A well executed Synergy type horn can provide stunning performance with quite pedestrian drivers.
A well executed Synergy type horn can provide stunning performance with quite pedestrian drivers.
Even for PA use? I say this because from what I've seen the greatest single output limit from most synergy horns (that I've tried, I don't pretend to be Danley...) is the low frequency output of the compression driver. I have struggled to ever get a reasonably sized (midrange) cone over 1k, and with most CD's 1k is only possible with 12db/Oct or greater.
Certainly for home use the rules are quite different - I assumed the OP was referring to PA use in his questions (however now re-reading I see the mention of a budget build, so that does rather rule out the coaxes 😅).
I'm genuinely interested in your input @cowanaudio as I've followed your website for many years and have been very impressed with your work.
Edit - spelling
Certainly for home use the rules are quite different - I assumed the OP was referring to PA use in his questions (however now re-reading I see the mention of a budget build, so that does rather rule out the coaxes 😅).
I'm genuinely interested in your input @cowanaudio as I've followed your website for many years and have been very impressed with your work.
Edit - spelling
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Sorry for the confusion, I mentioned a PA - but my application is for nearfield.
I am thinking at this stage to use an affordable CD Driver and pair it with 3 inch FaitalPro drivers, still on the look for some kind of woofer to compliment.
I am thinking at this stage to use an affordable CD Driver and pair it with 3 inch FaitalPro drivers, still on the look for some kind of woofer to compliment.
The updated Synergy Calc V5 detailed guide document was released in March 2014. A multiple entry horn loudspeaker wizard tool that takes the high frequency compression driver into account was added to Hornresp some time after the document was released.
A MEH template can be created using the Input Wizard and the parameter values then changed to suit the specific design.
See the Multiple Entry Horn Wizard and Two-Way or Three-Way Multiple Entry Horn sections in the Hornresp help file for further details.
Attachments
If I'm not mistaken, I published the second Unity horn clone online (John Sheerin was #1)
If I were making a Unity horn for nearfield use, I don't think I would make it anything like the Danley Synergy Horns:
- The first issue is that it's going to provide way more output than anyone would possibly use
- The second issue is that Unity horns (and MEH horns in general) tend to work better with narrower beamwidth. As the beamwidth gets wider and wider, you have to drop the xover point on the tweeter lower and lower, and eventually you'll have to do what Danley did in some Synergy Horns, which is using a coaxial compression driver, or use a beefy/expensive tweeter. Both approaches increase the complexity quite a bit, and are certainly more expensive.
- Most audiophiles agree that speakers with wide horizontal beamwidth and narrow vertical beamwidth sound best in real rooms. For sound reinforcement, narrow angles are fine, because the walls are much further away, or the speakers are outside.
My first "real" speakers were a set of JBL two-ways that used a cheap mylar tweeter on a waveguide and a "meh" woofer, and they sold for about $500 in 2000, or about the equivalent of what the KEFs sell for today.
Obviously, KEF is hardly the only solution, and I don't even own LS50s. But for nearfield listening, I think the optimum speaker would be something that's "on the spectrum" between the KEF LS50 and the Danley SH50.
Also, IMHO, the 'secret sauce' in the Danley Synergy Horns is the xover. I think people fixate too much on the geometry and what midbass to use and what compression driver to use. When the truth is that you can use relatively pedestrian parts in a speaker, and if you nail the xover, it makes all of the difference in the world. This is one of the reasons that the Beolab 50 is still my favorite speaker of all time, despite all of my diyaudio threads about Unity horns. The ability to alter the beamwidth and change the tonality of the speaker using an app on your phone is Next Level and it's bonkers (to me) that there are really only four speakers in the world that offer this. (And I'm not 100% sure if one of them was ever released.)
As Marc Andreesen wrote in The Wall Street Journal, "software is eating the world", and the ability to use software to tailor the sound like the Beolabs do is revolutionary.
If someone were able to take the concepts of the Beolab and implement them in a speaker that's about the size of an LS50, that would be a complete game changer. Beamwidth control, high WAF, and endless "tweakability." The only obvious downside is that it would consume a TON of power, but amplifiers are practically free these days.
(In case anyone wonders what I'm babbling about, and how it's related to Danley Synergy Horns: you can control beamwidth with a waveguide, but you can also control beamwidth by power tapering a multi element array, and also delaying some of the elements. The neat thing about doing it with software is that you can have a fairly wide set of beamwidths. Something I noticed with my very first Unity horn was that they were a revelation on well recorded music, but on poorly recorded music, they don't sound great. This isn't the fault of the Unity horn; it's the fault of the recording. Conventional speakers don't offer the option of having a "mode" that's like an x-ray for good recordings, and a mode that's diffuse for bad recordings. So people tend to buy audiophile speakers, and then they find themselves listening to boring audiophile recordings because their audiophile speakers are unforgiving of bad recordings.)
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They never became a production model. It was interesting playing with the BMS and B&C coaxial compression drivers to learn what they bring to the table.
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If you are referring to separate cone midrange 3-way Synergy™ designs, like the SH-50, then yes, you definitely don't need midrange cone MEHs--as I have stated before. This is why the 1.4" and 2" dual-diaphragm compression drivers exist. [You can now easily do the same job with better quality 1.4" and 2" single diaphragm drivers and a throat mounted diverging lens (3-D printed, but patented by Klipsch).]
The use of 1.4" or 2" dual-diaphragm compression drivers eliminates the complexity headaches and the audible internal diffraction issues in the 600-2000 Hz band that the separate cone midrange 3-way MEHs bring to the table. [This is from the experience of using a larger horn (a K-402 or SH-96-sized horn) to achieve full-range directivity control down to 100 Hz. This is something that the SH-50 really doesn't do very well: full-range directivity down to the listening room's Schroeder frequency. Having used both an SH-50 and a K-402-MEH in-room, I can say that the K-402-MEH approach sounds smoother/wider and much more refined than the SH-50, and its polars are much better for in-room directivity control in the low midbass region.]
Chris
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Hmmm...my thoughts and experiences run counter to some of those points.
I find the big advantage to having more output capability than needed, is simply how dang clear the speaker stays when turned up a little, even within normal home SPL levels.
In my mind, required SPL capability at home audio levels, is more about clean headroom for transients, than simply playing loud.
But I want 15dB min of clean headroom above average SPL....and any kind of number crunching shows it's hard to have too much SPL....if clean headroom is the goal.
I like a 90 degree horizontal beamwidth...it's simply my preference after having spent a lot of time with equivalently built/sized ,60 degree and 75 degree versions.
All versions have had a 60 degree vertical. 60 x 60 was clearly too narrow for me.
Plus, narrow pattern control requires much larger horns, both mouth size and depth, to match lowest frequency of pattern control of wider..
Oh, I don't understand why you say, as beamwidth gets wider, the tweeter's xover point needs to lower? (Thx for any clarity here...)
About every Danley Synergy PA design I've looked at, incorporate some form of small mids to span between the CD and the low drivers.
So if used, a coaxial compression driver appears to be being used for increased SPL, not for reaching lower in freq.
With small mids, a less SPL capable CD can be used, but complexity would be the same no matter what CD is being used.
I agree with the idea of wider horizontal and narrower vertical, for in room.
I think the issue with conical horns, is the H:V aspect ratio is pretty much limited to 1.5 -1.6 to avoid excessive pattern flip. I guess true for all horns.
So a 90 deg horiz, has a vertical narrow limit of 56-60 degrees, I think.
But maybe pattern flip is not so much of an issue in a room...I really don't know.
Well, I wouldn't say defeat the purpose, but I'd sure say unnecessary 🙂
Maybe the best sounding thing I've built, was a junker proto-type that used:
DCX464 HF & VHF
four 4fe35 Mids
two 10fe200 lows
It was a 90x60, 31"x 19", with no secondary flares.
I think any decent CD that can get to 1000Hz would work awesome in it.
And the 4fe35s and 10fe200's are sure inexpensive enough.
It's the only old proto-type I can't throw away...kinda reminds me of the Millennium Falcon adage...fastest piece of junk in the galaxy lol
If I may jump in with another related question - what is the formula for the flare rate that dictates the lowest end of the particular section? I found some, put numbers in, but it does not seem correct. An example how to calculate it would be appreciated, an example would be perfect, too. I found a way how to do that via Hornresp, but I would like to make it in a spreadsheet.
Did the ones that look like a monolith go into production? I was interested in buying a pair but I couldn't find them on Etsy any longer.