M2 Synergy Horn

I have a Folgertech FT-5. Very nice printer, but kind of a b***h to build.

https://www.folgertech.com/products/folger-tech-ft-5-large-scale-3d-printer-kit
Use code "FOLGERTECHFBGROUP" for another 11% off.
It also needs some add-ons (cooling fan, better powersupply at least).

And if you're going to do waveguides or something that big, a Titan type extruder (or cheap Chinese clone of same) and Volcano setup would be a good idea to make print times reasonable (true with any printer, I think). I'm down to where one of my horns takes about 22hrs (11hrs per half) -- not counting prints where something screws up and I had to start over!
 
Those jerks at monoprice really want me to buy a second printer

The one that I have, that was a steal for $399, is now $318:

https://www.monoprice.com/product?p_id=13860

Well, diving in. Managed to get an open-box PowerSpec version of the Wanhao i3 at the local MicroCenter for $240.

Also ordered one of these https://www.millrightcnc.com/ and a DeWalt DW660 to complete the computer-controlled insanity project. Nothing like trying to climb multiple learning curves at once

I mainly see these as machines to build machines, but we'll see how it goes.
 
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Last week I did some work with Voishvillo type phase plugs, and it seemed to work out well.

I was curious to see how that would work on a Synergy Horn, so I thought I'd take a crack at it.

I think there's a fairly good chance this won't work, but the only way to find out is to build it.

Here's some pics of the model.

Hi Patrick
This is an excellent design.
You may send the stl file here
Understand your 3D printing price

They have a multitude of printers , you specify the material and the color and they will give you a quote.
Since you know how much time it costs you to print it at home and you understand the difficulties, I think you will be in position to judge the price they charge.
If you do try (you don’t have to print it through them, just send the stl file) to see what the price is, please let us know.
Such kind of service frees anyone from the limitations of a particular printer

George
 
Spoiler alert:

All the waveguides with those really deep "M2 style" ridges don't perform well. A diffraction slot is still a diffraction slot.

I measured a few of these and they were bad enough I didn't waste any time posting the results.

Also, note that JBL itself has moved away from those really deep ridges on everything they've made since the M2.
 
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Spoiler alert:

All the waveguides with those really deep "M2 style" ridges don't perform well. A diffraction slot is still a diffraction slot.

I measured a few of these and they were bad enough I didn't waste any time posting the results.

Also, note that JBL itself has moved away from those really deep ridges on everything they've made since the M2.
Please post your measurements if you still have them. Negative results are still results, and even if analyzing them won't bring us towards improvement, at least future designers won't fall into the same pits again.

BTW, diffraction slot doesn't have to be bad. Our German colleagues seem to have made significant success in calculating optimal horn profiles through Comsol iterations, and some of them employ wavefront constriction in one or two planes. One design looks like a higly smoothed Mantaray, another like a cross of Mantaray and E-JMLC-1000, both seem to produce good polars. I read through Chrome in-built Google Translate. Entire thread is a goldmine.
https://www.diy-hifi-forum.eu/forum...oder-Constant-Directivity-wie-geht-das/page33
 
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Hi Vox, thanks for keeping interest in our thread! Feels nice to see that more people seem to enjoy our endevor.

Yeah I was also quite suprised that I went full circle "back" to Mantaray.

Currently there are no diffraction slots in Use. In Post #658 I show that the distance offset I use to bring both curves to the same plane at the mouth does not change the directivety, even if there is quite some edge, therefore it does not create a diffraction edge*. If you have questions or suggestions feel free to pm me or ask me here.

Next step is to check if different Wavefronts could improve the polars or enable the use of other curves. For example the Offset that brings the Mantaray look only works with plane input waves*. Maybe a different waveshape could make it obsolete but I have to brush up my theoretical knowledge for that. The Programm to create a Phaseplug is almost done but I have to know what to aim for first.

Maybe Sunday I will come around to making a new post. Privat life is busy atm.



*Also I still think that a diffraction edge is still ill defined. At which point does an edge add diffraction? I think its a fluid transition from no diffraction to some to full out edge.
**I hope you like my handdrawings, because there are prolly gonna be more =D
***Or at least in the vertical plane
 
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