Thinking this combination would sound good, but Im unclear if the pattern emitted by the ribbon/planar is already too focused to take advantage of the MEH wave guide..
Also wondering if anyone knows of a reasonably priced and small ribbon that I can cross at 800Hz for a 2 way MEH build?
looking at this but its pretty anemic: would prefer a real ribbon..
https://radianaudio.com/collections/ribbon/products/lm8k-wide-band-planar-ribbon-transducer
Also wondering if anyone knows of a reasonably priced and small ribbon that I can cross at 800Hz for a 2 way MEH build?
looking at this but its pretty anemic: would prefer a real ribbon..
https://radianaudio.com/collections/ribbon/products/lm8k-wide-band-planar-ribbon-transducer
There are basically no true ribbons, or even planars for that matter, that will be happy crossing at 800Hz that are affordable and small. The Parts Express 8" planar or the Radian you linked will do it, but they are perhaps too tall for a MEH? The only true ribbons I've ever seen for diy same that could have crossed that low is the Raven line source, but it's large and expensive.
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I think a ring radiator compression driver would approach the transient response of a planar and could be crossed lower. The BMS4550 may be an option. It depends alot on the output level expected from the driver.
Google "ribbon unity horn diyaudio"
I've done it a few times, it works "alright"
There are two challenges:
1) The wavefront of most ribbons is asymmetrical. Typically wide on the horizontal axis and narrow on the vertical axis. This can basically wreck the entire "concept" of a Unity horn, because a unity horn is supposed to be a wide bandwidth point source. With a ribbon or planar at the throat, the pattern will typically change as the wavelengths become smaller at high frequency. IE, at 8khz, you may find that the pattern doesn't match the rest of the horn, because the ribbon is larger than the wavefront it's generating. 8khz is 4.25cm wide. Most ribbons are taller than that; net effect is that the ribbon is producing a planar wavefront at high frequency and a spherical wavefront below that frequency. I know that all of that sounds kind of pedantic, but it's not. The entire idea of a Unity or Synergy horn is point source behavior across the bandwidth. If your speaker is making a planar wavefront at 8khz and a spherical wavefront at 4khz, then that means that the overall frequency response will vary on how far you are from the speaker. (Planar waves are "long throw" while spherical waves are "short throw.") It's a bit like trying to make a lamp work, when part of the lamp features a light bulb and part of the light features a laser. This same phenomenon is much much worse with speakers like Magnepan and Martin Logan and the like, because they try and crossover from a planar wavefront (the big electrostatic panel) to a spherical wavefront (the conventional woofer at the bottom) with mixed success.
2) With a planar or ribbon, it can sometimes be impossible to fit midranges to the top and the bottom of the Unity horn. Basically, it's not possible to get them close enough.
Having said all that, I would not discourage you from building one. They're tricky but not impossible. In a lot of ways, the Danley Jericho horns behave as if there's one big ol' ribbon at the throat. Something that Danley does, which you could replicate with planars or ribbons IF you're good at 3D printing, is that Danley curves the wavefront that's exiting the throat. IE, in a Jericho horn, the vertical beamwidth isn't ZERO degrees; it's something like 20-40 degrees, depending on the model.
Oh, wait, one thing more!
I leave it up to you to research this thing, because I've never been able to come up with a 100% satisfactory answer:
When you have a Unity horn where the high frequencies are NOT conventional, my 'hunch' is that the vertical height of the device likely needs to be AT LEAST as big as the lowest frequency that the tweeter is reproducing.
Here's an INSANELY cheap ribbon Unity horn I built, to illustrate what I mean. If you look at the parts in this junky thing that I built, you'd be astounded by how simple/cheap/basic it is:
That's a $40 Fountek ribbon tweeter, cheapest one they ever sold. The midranges are Misco, they sell for one dollar each on eBay. I have around a hundred, you have to buy them in bulk lol. The crossover is around three components, randomly assembled from parts I found in my garage. I didn't buy ANYTHING for this speaker, just put them together like Frankenstein from junk in my garage. Despite all that, it doesn't sound awful and even without an enclosure, it's playing down to 500Hz-ish. I documented it on diyaudio, I think I posted measurements. It was half a decade ago.
Crossover is probably around 1khz or so, 1khz is 34cm in diameter. So the Unity horn is just big enough to accommodate a wavelength of 1khz.
For comparison's sake, here's a Unity horn I made with dual 5" woofers and a 29mm dome tweeter from SB Acoustics. The SB tweeter is considered "better" but I personally think that the Fountek ribbon has some "sparkle" and "air" that the SB is missing:
What I just said is very subjective; it is possible that the SB just needs some more EQ or something. But I consistently found that domes on Unity horns would often sound "dark" and I'm not 100% sure why.
Something that is VERY APPARENT when you compare the two videos, is that the ribbon has MUCH "longer throw." With the 2nd video, you can REALLY hear how the SPL drops off as you get off axis. That's the "point source" thing that Unity horns do so, so well. Like taking a flashlight and just turning it away from you, the "light" just drops off a cliff.
That can be a defect: if you're trying to maintain the same SPL from the front to the back of a room, you're going to want to skip point source Unity horns. Their SPL drops a lot with distance, they're point sources.
That can be a feature: if you listen at home and you don't want to bug your family/neighbors, that aspect of Unity horn behavior can be a Godsend.
Really depends on what your priorities are. Have fun! Happy Holidays.
P.S.
I've never had any issue with blowing up ribbons or planars on Unity horns.
So in regards to your question, as to which to buy, I'd say "buy whatever one suits your application."
I know Mark isn't a fan of the Airborne AMTs I used on one of my Unity horns, so you might want to consult with him. He's had AMTs manufactured for his company and I believe he designed them too.
The reason why planars and ribbons are surprisingly durable on Unity horns is because planars and ribbons tend to explode due to overexcursion.
Here's the math:
Let's say you have a planar or ribbon, and you are crossing it over at 2khz in a conventional two way speaker. Since the planar / ribbon is on a flat baffle, there will be a point where the wavefront generated by the ribbon / planar is wrapping AROUND the baffle. For instance, if you put a planar / ribbon in a conventional two-way, and you use a crossover point of 2khz, and the baffle is 20cm wide, this means that when the wavefront is larger than 20cm, the wavefront is wrapping around the baffle. IE, even with a xover of 2khz, when the planar/ribbon is radiating 1khz, that wavefront is wrapping around the baffle. The wavefront is bigger than the baffle. THIS is the thing that blows planars/ribbons to bits. You have this fragile piece of mylar, and you're telling it to produce 1khz at 100SPL or God forbid 110SPL, and it just doesn't have enough displacement to do that. IT GOES BOOM! Easiest fix for this, in a conventional two way, would be to use a wide baffle or a steep high pass.
On the other hand, when you put that very same planar/ribbon on a horn, that wavefront CANNOT wrap around the baffle because the wavefront is smaller than the baffle. For instance, if you used a 1khz highpass on a planar unity horn, as long as the waveguide itself is at least 34-68cm in diameter, that wavefront is NOT wrapping around the baffle. The radiation of the tweeter has been constrained to a narrower angle. That raises the on-axis output so that you can get away with using less power, and that keeps the planar/ribbon from exploding. On top of all of that, the horn is also providing some "gain" via horn loading.
Put all of that together, and I wouldn't lose any sleep crossing a planar/ribbon over at 1khz on a Unity horn, even though the very same tweeter will likely fail if you used the same xover point in a conventional two-way.
To give you an idea of how well this works, consider that the tweeter in the Danley SH-50 (BMS 4550 tweeter) has much LESS displacement than a typical ribbon or planar tweeter. Max SPL on the SH-50 is something ridiculous like 130dB. If I can get a $40 Fountek tweeter to work with various parts found on my workbench, just imagine what's possible with a well researched project.
I've never had any issue with blowing up ribbons or planars on Unity horns.
So in regards to your question, as to which to buy, I'd say "buy whatever one suits your application."
I know Mark isn't a fan of the Airborne AMTs I used on one of my Unity horns, so you might want to consult with him. He's had AMTs manufactured for his company and I believe he designed them too.
The reason why planars and ribbons are surprisingly durable on Unity horns is because planars and ribbons tend to explode due to overexcursion.
Here's the math:
Let's say you have a planar or ribbon, and you are crossing it over at 2khz in a conventional two way speaker. Since the planar / ribbon is on a flat baffle, there will be a point where the wavefront generated by the ribbon / planar is wrapping AROUND the baffle. For instance, if you put a planar / ribbon in a conventional two-way, and you use a crossover point of 2khz, and the baffle is 20cm wide, this means that when the wavefront is larger than 20cm, the wavefront is wrapping around the baffle. IE, even with a xover of 2khz, when the planar/ribbon is radiating 1khz, that wavefront is wrapping around the baffle. The wavefront is bigger than the baffle. THIS is the thing that blows planars/ribbons to bits. You have this fragile piece of mylar, and you're telling it to produce 1khz at 100SPL or God forbid 110SPL, and it just doesn't have enough displacement to do that. IT GOES BOOM! Easiest fix for this, in a conventional two way, would be to use a wide baffle or a steep high pass.
On the other hand, when you put that very same planar/ribbon on a horn, that wavefront CANNOT wrap around the baffle because the wavefront is smaller than the baffle. For instance, if you used a 1khz highpass on a planar unity horn, as long as the waveguide itself is at least 34-68cm in diameter, that wavefront is NOT wrapping around the baffle. The radiation of the tweeter has been constrained to a narrower angle. That raises the on-axis output so that you can get away with using less power, and that keeps the planar/ribbon from exploding. On top of all of that, the horn is also providing some "gain" via horn loading.
Put all of that together, and I wouldn't lose any sleep crossing a planar/ribbon over at 1khz on a Unity horn, even though the very same tweeter will likely fail if you used the same xover point in a conventional two-way.
To give you an idea of how well this works, consider that the tweeter in the Danley SH-50 (BMS 4550 tweeter) has much LESS displacement than a typical ribbon or planar tweeter. Max SPL on the SH-50 is something ridiculous like 130dB. If I can get a $40 Fountek tweeter to work with various parts found on my workbench, just imagine what's possible with a well researched project.
Folks, thank you for the guidance. And Patrick thank you for the in depth write up!
Im still defining my project objective. Iv gone back and forth quite a bit as I dig, research, educate myself with past posts.
I used to think that I wanted to melt peoples faces off with the most efficient, compact unit I could build. But I think my objective is moving to more of a "HI-Fi PA". The planer in a synergy is sounding like its introducing a set of problems that I probably shouldn't take on.
So the BMS4550 may be the way to go, and is priced better then the CDX14-3055.
Although maybe under powered: what do you think of the FaitalPRO HF108 for a 2 way synergy? Their frequency plot is seductively flat.
Im still defining my project objective. Iv gone back and forth quite a bit as I dig, research, educate myself with past posts.
I used to think that I wanted to melt peoples faces off with the most efficient, compact unit I could build. But I think my objective is moving to more of a "HI-Fi PA". The planer in a synergy is sounding like its introducing a set of problems that I probably shouldn't take on.
So the BMS4550 may be the way to go, and is priced better then the CDX14-3055.
Although maybe under powered: what do you think of the FaitalPRO HF108 for a 2 way synergy? Their frequency plot is seductively flat.
Very sensible explanation why a planar is not a good fit for the MEH principle.
I think this is good reasoning. It's not only counterintuitive but also technically flawed.
Can you provide your listening levels and (planned) distance of the LP to the speakers? For iOS devices DecibelX is supposedly good enough, if you have one.
It would need to keep up with a THAM15, recommended cutoff is 131 hz . But it would be it would be nice to use the tops on their own at cut off at +-70hz with a larger horn mouth. This is were some of the rumination is coming from.
Danley THmini15 specs are fairly close to output
https://www.danleysoundlabs.com/wp-content/uploads/2023/02/THmini15-Spec-Sheet-Rev.20230331.pdf
Danley THmini15 specs are fairly close to output
https://www.danleysoundlabs.com/wp-content/uploads/2023/02/THmini15-Spec-Sheet-Rev.20230331.pdf