I agree with Marcel, without some real data, I'd have to assume that the sims are correct. If this really worked well, then I would expect any company to show the data as an advertisement of the feature. Not so much if it didn't work too well.
Sounds very suspicious to me.
So it's a pizza tonno, only without tuna.
Thank's for the clarification.
The effectiveness of such a lens is minimal, which has been proven by a large number of K402 owners who've used the horns with different drivers excluding lens.
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Does Klipsch actually provide a directivity plot of their speaker?
I'm yet to see a 2" driver having an uniform directivity above 10k that exceeds 15 degrees.
The ESP tests I made actually worked, however I never managed to get rid of the dips the plug introduced.
I think a very exotic idea is to make a multicell ish version of the plug that starts as semi rings and turns in to rectangles.
I also didn't try making an elliptical horn sitting on an ESP plug.
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I have not found any directly provided by Klipsch, but also can't find any spec sheets for the Cinema systems the K-402 was designed for around the year 2020.
Chris A (Cask05 on DIY audio) has posted polar plots of the K-402:
https://community.klipsch.com/index...r-patterns-and-frequency-responses-for-horns/
In posts #201 Cask05 posts and #218 he posts more, and his MEH K-402 using two 15" woofers, though none quite agree with each other:
https://www.diyaudio.com/community/threads/best-compression-drivers-today-2022.382609/page-11
Last year he installed Roy Delgado's "phase plug extension horn throat diverging acoustic lens" as depicted in post 205 of the above thread, but has not done a comparative polar measurement test with and without and is "not sure that the polar sonograms will show that much".
So no actual measurements of what the parallel rings do, or the dips they introduce, or how they would compare to your ESP tests.
I'd really enjoy seeing you testing out the concept, but based on Marcel's models and all the above, wouldn't expect to see a net measurable positive improvement in VHF constant coverage.
Art
Hey Art,
I do believe Marcel's implementation of the plug works, it just has to be implemented in a proper way.
My inability to get a working device together is mostly due to mistakes I've made.
I also tried making an overcomplicated version of the ESP plug using Grasshopper, but it had a much worse performance.
After the summer I'll give the Rectangular ESP device a go. Using narrow channels instead of rings. (kind of like the multicell)
I do believe Marcel's implementation of the plug works, it just has to be implemented in a proper way.
My inability to get a working device together is mostly due to mistakes I've made.
I also tried making an overcomplicated version of the ESP plug using Grasshopper, but it had a much worse performance.
After the summer I'll give the Rectangular ESP device a go. Using narrow channels instead of rings. (kind of like the multicell)
Just tested a 2-profile geometry with mouth folding. The simplest approach was to define a R-OSSE profile on the diagonal with a defined inclination.
Horizontal, vertical, diagonal (garbage above 10 kHz):
To repeat, by "2-profile" I mean a shape composed of a symmetric pair of two flat or bended boards (easy to make in any size) + a short circle-to-rectangle throat adapter.
Horizontal, vertical, diagonal (garbage above 10 kHz):
To repeat, by "2-profile" I mean a shape composed of a symmetric pair of two flat or bended boards (easy to make in any size) + a short circle-to-rectangle throat adapter.
This is interesting I am working on multi driver throat adapters at the moment and the only process for generating them I can think of is to create a point cloud in matlab/octave and then fit a surface to that, this is not ideal though as the geometry is quantized. I am not a CAD expert though. My throat adapters preserve the horn area expansion (exponential), incorporate bends (for multi driver) and also perform round to rectangular transition. Have you any thoughts on a better way of making them?
You mean other than via a point cloud? I'm not sure what are incorporated bends, that may be an obstacle, but if you are able to cut the adapter into slices of known geometry, it's easy to import the whole (interpolated) surface into e.g. Fusion 360 - I have a new and pretty universal import script for that which I can share.
There are many ways to make it worse. One of them is to increase aspect ratio of the mouth. This is the same diagonal profile as above, I only changed its inclination to 12 deg (mouth 700 x 180 mm):
This sounds like it would work with my bends as well. The bend is just a simple radius (I don't know if this is optimal, it just seemed like a simple thing to try first)
Should be easy to fit with two OSSE profiles. It's possible with the 4.9.0 pre-release: https://at-horns.eu
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For those willing to pursue this kind of geometry, this would be a project template (replace the numbers by your best fit - I didn't try):
Code:
HornGeometry = 2
Length = 340
Throat.Diameter = 50
Horn.Adapter = {
L = 0
Width = 54
Height = 54
Segments = 1
}
Horn.Part:1 = {
L = 1
Segments = 16
H = {
k = 0
a = 42
s = 0.7
n = 6.0
q = 0.98
}
V = {
k = 0
a = 30
s = 0.6
n = 6.0
q = 0.98
}
ZMap = 0.5,0.5,0.5,0.9
}
; -------------------------------------------------------
Mesh.AngularSegments = 64
Mesh.ThroatResolution = 10
Mesh.MouthResolution = 16
Mesh.InterfaceResolution = 10
Mesh.RearResolution = 25
Mesh.SubdomainSlices = -2
Mesh.InterfaceOffset = 0
Mesh.WallThickness = 10
; -------------------------------------------------------
ABEC.SimType = 2
ABEC.f1 = 200 ; [Hz]
ABEC.f2 = 20000 ; [Hz]
ABEC.NumFrequencies = 40
ABEC.MeshFrequency = 1000 ; [Hz]
ABEC.Polars:SPL_H = {
MapAngleRange = 0,180,37
Distance = 2
}
ABEC.Polars:SPL_V = {
MapAngleRange = 0,180,37
Distance = 2
Inclination = 90
}
Report = {
Title = "K-horn test"
PolarData = SPL_H
NormAngle = 0
Width = 1400
Height = 800
}
Output.STL = 0
Output.ABECProject = 1For the ABEC mesh (Output.ABECProject) it's fine to set the adapter size the same as the throat diameter:
Throat.Diameter = 50 ;[mm]
Horn.Adapter = {
L = 0
Width = 50
Height = 50
Segments = 1
}
i.e. there will be no spaces between the source disc and the walls -
For the STL output (Output.STL) this doesn't work yet.
Throat.Diameter = 50 ;[mm]
Horn.Adapter = {
L = 0
Width = 50
Height = 50
Segments = 1
}
i.e. there will be no spaces between the source disc and the walls -
For the STL output (Output.STL) this doesn't work yet.