Interesting.. I have RCF ND950 2.0 and could try it with 460-36. Would it be possible to get the file of that conical connector? Or is it so simple that just a 3d-printed shrink tube with 60mm length would suit job?
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That's driver-specific. As the ND950 2.0 is obviously the 1.4" version with an additional throat adapter, it's probably best to replace the existing adapter with a "phase-plug to 1.4 throat" adapter instead (or just try to use it without the existing one). Its length will affect the tuning frequency of the extension, which should also/ideally match the driver in some way, but that's not solved yet, 60 - 100 mm should work. This is nothing but a cut-and-try approach at the moment...
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Thanks for reply mabat. I will disassemble the ND950 and study for a suitable fitting, maybe more for different lengths for testing. Ill receive tomorrow X1C 3d-printer and going to print 460-36 petals from this link: https://at-horns.eu/img/athex/ATHEX-460-36-CAST.stl (need splitting for X1C still)
I couldn't find a base unit for petals, is there one available?
I couldn't find a base unit for petals, is there one available?
A post discussing resonances that occur due to slotted baffles, also with the synergy horn application: https://www.audiosciencereview.com/...d-baffles-i-e-graham-audio.45472/post-1621006
I used the slotted baffle technique in a slightly different way, as throat for a fullrange driver (fe127) with a tractrix front horn. My idea was to have some compression and better dispersion by making the rectangular throat about 1/3 less wide and the height the same as the cone. Worked well but in that time I could not measure it, so a subjective conclusion based on listening.
This is what I used (attached) but with a 3D printer on hand, you can easily create your own that will suit your needs the best...
I tried to clean a bit the throat/extension/WG interface - still not perfect but better 
Polars at some off-axis angles (roughly 0/10/20/30), gate ~5 ms:
0 - 30 cm from the center of the mouth at 4 steps with a longer gate (~18 ms):
ATHEX 460-36/EXT + 1" Peerless DFM-2535R00-08
Polars at some off-axis angles (roughly 0/10/20/30), gate ~5 ms:
0 - 30 cm from the center of the mouth at 4 steps with a longer gate (~18 ms):
ATHEX 460-36/EXT + 1" Peerless DFM-2535R00-08
I haven't tried at the moment, as making a proper crossover would need to be done much more carefully than e.g. with the big driver, which seems to be a very forgiving setup.
There's really a great potential in using large-format drivers at their phase plug exits, even if radiating e.g. through a 1.4" aperture.
If we can reach 500 Hz with such an ease, there's really no reason for any MEH or something, IMO.
There's really a great potential in using large-format drivers at their phase plug exits, even if radiating e.g. through a 1.4" aperture.
If we can reach 500 Hz with such an ease, there's really no reason for any MEH or something, IMO.
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No, only the STLs. For an own experimenting I can only recommnend the 460-36 which seems to be a good all-round performer, big enough, which is still important.
As for a driver, I really don't know. I don't have any dreamt-of. That's also the reason I publish these designs - to let to test whatever people already have.
As for a driver, I really don't know. I don't have any dreamt-of. That's also the reason I publish these designs - to let to test whatever people already have.
BTW, the D2500Ti-Nd was also very pleasant to listen, virtually without any filtering/EQ needed, other than a basic high-pass around 500 Hz.
The raw response in 460-36/EXT -
The raw response in 460-36/EXT -
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Besides small exit Angle...any hint what could be relevant parameters of the driver for lf extension? Changing tube length is surely something I should try then, too.
Will check later how to change in CAD with existing stl (grab the curvature from it) to a Okta-Design....imagine a nice red-white Umbrella Corporation design ;-)
As far as I read here it should not influence performance largely...?
Might be some work as need to re-design for that but does not matter. Look would be cool in my home cinema
Will check later how to change in CAD with existing stl (grab the curvature from it) to a Okta-Design....imagine a nice red-white Umbrella Corporation design ;-)
As far as I read here it should not influence performance largely...?
Might be some work as need to re-design for that but does not matter. Look would be cool in my home cinema
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I'm not sure about the small exit angle as a requirement. For example the D2500Ti-Nd (a photo below) has a pretty wide-angle exit section, although only short. Then if I wanted to try to get a maximum out of it, I would try to start the extension at the phase plug exit, perhaps even with something else than a conical shape. Small exit angle is probably good if you want to use a stock 1" driver as it is...
What about CD membrane design? Your tested drivers all have a dome diaphragm. May a BMS ring diaphragm behave different? Or the HF1440 I have here (unfortunately 1.4"....otherwise for even extended low end interesting). The LF extensions "uses" some resonance. the impedance of the CD diaphragm could make a difference here regarding its stiffness/withstand...