It appears the curved walls of the compression driver's phase plug are visible behind the parallel walls of the rings. The photograph is taken from above the horn axis, contributing to what you seem to see as misalignment.
5 rings:
All rings the same height (5 mm):
I just don't see this working in any useful way but there might be a magic overlooked. Maybe in a horn it will be different.
It's a standard part of Ath now so it can be simulated in a horn. If I ever make another release, it will be there.
All rings the same height (5 mm):
I just don't see this working in any useful way but there might be a magic overlooked. Maybe in a horn it will be different.
It's a standard part of Ath now so it can be simulated in a horn. If I ever make another release, it will be there.
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You may be right.
Anyway, in my view the lens mainly serves as a diffuser to somewhat compensate for the lacking response of the Axi2050 in combination with the K402.
Besides, it's also a fragile dust collector.
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Tried with an axisymmetric waveguide (FWIW). It may be already difficult to simulate this reliably.
It's hard to say what it really does or not, it's possible it can smooth the onset of beaming a bit. My guess is that the predicted sharp peaks and dips won't be so pronounced in reality.
Flat source + rings:
Flat source:
Spherical source:
It's hard to say what it really does or not, it's possible it can smooth the onset of beaming a bit. My guess is that the predicted sharp peaks and dips won't be so pronounced in reality.
Flat source + rings:
Flat source:
Spherical source:
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Working on a throat "bypass plug" for the ST260/CD131 combo (WG profile also changed to R-OSSE) -
BTW, this is again ⌀260mm. I'm still hesitating to make it bigger - I'm not sure the driver would handle that anyway.
BTW, this is again ⌀260mm. I'm still hesitating to make it bigger - I'm not sure the driver would handle that anyway.
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So with a spherical source it may be worth it.
What's left is the interaction with the horn profile and the throat section, which in the case of the K402 consists of outwardly curved triangles.
And as so often, a (patented) novelty turns out to be not as new as suggested.
Initially, the K402 came with B&C DE75s including a 'custom' phase plug. The phase plugs of my own DE75s are definitely different.
A factory photo of the 'old' K402 from around 2017. Again, zoom in.
What's left is the interaction with the horn profile and the throat section, which in the case of the K402 consists of outwardly curved triangles.
And as so often, a (patented) novelty turns out to be not as new as suggested.
Initially, the K402 came with B&C DE75s including a 'custom' phase plug. The phase plugs of my own DE75s are definitely different.
A factory photo of the 'old' K402 from around 2017. Again, zoom in.
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Yea, you are, as usual. There are no rings in that example. Why would anyone add those rings to a spherical source?
Obviously, they wouldn't.Yea, you are, as usual. There are no rings in that example. Why would anyone add those rings to a spherical source?
My conjecture was that diffraction normal to the exits in Roy Delgado's Klipsch "phase plug extension horn throat diverging acoustic lens" would emulate a spherical source in the upper octaves (5-20kHz), your simulations show that not to be the case.
I recall you had some response oddities when the simulated distance was not in the far field, what was the simulated measurement distance in these recent tests?
Do diffraction effects consistently change with frequency in the model?
To go from flat wavefront to spherical you really need someting like this: https://at-horns.eu/release/Ath-AP1.pdf
At least in theory (confirmed by simulations), that device actually produces spherical wavefront if driven by a flat one.
The problem is that it's apparently not easy to find a driver with flat enough exit wavefront. For example the Axi2050 doesn't seem to comply.
At least in theory (confirmed by simulations), that device actually produces spherical wavefront if driven by a flat one.
The problem is that it's apparently not easy to find a driver with flat enough exit wavefront. For example the Axi2050 doesn't seem to comply.
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Yea, you are, as usual. There are no rings in that example. Why would anyone add those rings to a spherical source?
What is suggested by this caption?
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That's just a name of a common project, mainly sharing the same waveguide. The title in parentheses (and the attached image) then "suggests" that the driving section has been replaced by a spherical source in that particular case. Maybe you'd best go somewhere where you can follow without such questions.
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Earl,
Marcel’s (Mabat’s) ESP (External Shaping Plug) for converting a flat wavefront to spherical clearly works both in the ATH/ABEC model and in measured responses.
As modeled in ABEC by Marcel, Roy Delgado's "phase plug extension horn throat diverging acoustic lens" using five parallel nested tubes forming an ellipse at the exit does not work like his ESP device using different path lengths with an elliptical exit.
Roy has been measuring and modifying various manufacturer’s driver’s phase plugs for years to make them work better with his Klipsch 2” entrance K-402 conic/tractrix horn, though sharing the results of his “50 cent part” with the DIY community are not part of the Klipsch business model.
The ABEC model may not see Roy's “diverging acoustic lens" as a diffraction device.
As Marcel wrote in post #10,385 and 10386, “It may be already difficult to simulate this reliably. It's hard to say what it really does or not, it's possible it can smooth the onset of beaming a bit…(these may already be just numerical glitches)”.
I do appreciate the effort Marcel has put into this, but share his concerns with the reliability of the simulations compared to a measured response.
Art
Without actual data it's just hard not to be sceptical. I mean, it would be great if it worked, as it would be a simple and easily replaceable addition to existing devices, but so far nothing indicates it really works as intended (if I can assume the intention, i.e. to lessen the HF beaming of a 2" source).
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