ATH4 waveguide inspired multi way

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#41
It's not a secret just a combination of parameters to get the orientation that I wanted. You can see with the spectrum hints if you have it oriented as you want. The Horizontal is set to zx plane, the verticals zy, so the up and down are set using 0 and 180 for inclination.

Spectrum Hints.png
 
#42
Just had a look at generating farfield and also at 2 meters. Subtle difference.

Horizontal "farfield"

PolarRange=0,180,37
Farfield=true
BasePlane=zx
NormalizingAngle=10

1648815622840.png


Horizontal "2m"

PolarRange=0,180,37
Distance=2m
BasePlane=zx
NormalizingAngle=10

1648815940174.png
 
#45
If the situation is not symmetric, like the verticals here (UP vs DOWN), you can't normalize both (separate) charts to 10 deg - that's just not physically possible. If it's symmetric, it's fine to normalize to whatever angle you want because that's what you can -in principle- get if equalized. That's not possible for verticals here so the only option to normalize would be 0 deg (on-axis).

- Or make the polar map a single chart (-180 -> 180) and then you can normalize to whatever angle you want.
 
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#48
What's the number of frequencies ? Looks very detailed.

Until now, I have not understood the merrit of the "Linear zero" option. Isn't it better if one can see the typical thresholds, that i. e. define pattern width at -6 dB as a color change?
 
#50
sheeple said:
What's the number of frequencies ? Looks very detailed.

Until now, I have not understood the merrit of the "Linear zero" option. Isn't it better if one can see the typical thresholds, that i. e. define pattern width at -6 dB as a color change?
Click to expand...

H
Distance=3m
BasePlane=zx
NormalizingAngle=0
501 Inclination=0 ID=5001

Normalised to global max amplitude - for comparision to SEOS charts?
1648830127239.png
 
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#54
fluid said:
To keep the spacing the same between angular increments the last number should be 73 when you simulate 360 in one go. That way if you use the command contour from curves you can turn a polar map into a collection of polar curves evenly spaced (5 degrees separation for above), I find these to be one of the most helpful graphs.
Click to expand...
Thanks! I'll give it a go.
 
#55
Friday night rabbit hole. Good to see the test apparatus and measurements!

C. Bateman - Distortion measurements of C0G ceramic and films

https://linearaudio.nl/sites/linearaudio.net/files/Bateman EW 11 2002 mar 2003 caps 100 nF to 1uF.pdf

400V 100n TDK B32652 series - 0.00005% @ 30V DC bias
https://www.mouser.co.uk/c/passive-components/capacitors/film-capacitors/?q=B32652&voltage rating dc=400 VDC

"Distortions from these 0.1μF and 1μF Epcos Polypropylene capacitors were not bettered by any similar sized capacitor I tested.
With double the PCB footprint of the (KEMET) SMR types, however, they may not fit your available space."
 
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#58
this one is pretty! one for the wall..

V56 horizontal polars in cabinet, 450w x 680h x 250d with 28mm rads all around.

What is the cause of the 1.2k contraction?

We can see the baffle step here too.


20-20k
1648945814841.png



1648946122818.png


100-15k @ 30deg
1648946328826.png


100-15k @ 45deg
1648946559872.png


100-15k @ 60deg
1648947217294.png


100-15k @ 45deg black line

1648946689710.png
 
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#59
limacon said:
What is the cause of the 1.2k contraction?
Click to expand...
Since this was introduced as you put the waveguide in the box I'd guess the waveguide profile and enclosure roundover don't mate well? Perhaps easiest test would be to increase the baffle roundovers to see if this goes away? I mean it might be hard to find optimal shape for the waveguide if it is simulated separately in infinite baffle and then put to box trying to simulate the whole system, well at least takes some time to find out 🙂 Did you try deeper box,if and how the features of the response changes?
 
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