Acoustic Horn Design – The Easy Way (Ath4)

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But you're going to use an 18" woofer with ATHEX460? I'm interested in the real life compromises of going with a 15 or even a 12. Did you give up on Cardioid for lower mid/ upper bass?
It will be all similar and these waveguides are pretty forgiving regarding a crossover frequency. I didn't give up on the cardioid at all, I just have a lot of different projects running...

Can you give a clue how you went about calculating this? I've seen the sketches in F360 but I can't think of an easy way of working out the transitions. I've rather fudged the issue in the past.
Sorry, I can't show you :)
It's just that the profile parameters are modified in all the different radial directions so it matches smoothly the petal sheet as a result. I decided to keep this proprietary.
 
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What happen when you scale down the st-260 and ad a roundish back chamber/cabinet and taps for a 4” midrange cone?
I know..

I used the st-260 scaled it down to a 12mm throat, modified the back and fitted it on a cheap 4” coaxial from Thomann in house brand The Box.
The coaxial has a cylindrical hole thru the midrange motor structure and originally a small horn for the tiny compression driver.

I added ~ 4cm open cell foam in the cylindrical part near the throat of the waveguide that cleaned up some peaks and valleys for both of the drivers frequency response .
And from yesterdays measurement. I think this fun experiment can become something useful. Or not, it’s all for fun anyway.

I always wanted to try Danley’ solution for adding a coaxial as part of a synergy horn but my printer bed is limited. Ergo I fiddled with a tiny coaxial and accept the limitations.

I apologize for the snapshots of the measurement but the time ran out. The battery on the laptop died as I was about to hear the first actual music. Literally pushed play and it died..

Side note: it’s only a 6ms window, no smoothing. Bad measurement conditions.
 

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Got my eye on a bigger coaxial if I ever get a bigger printer and that’s the Redcatt 6” https://redcatt.de/REDCATT-CX601X8
On the manufacturers site they even provide 3d-files so it simply a matter of making a fitting cone that buts up again there “throat cone”
Then the compression driver is more capable but as you said bigger throat size.

The raw response of the tweeter is actually quite impressive and linear. The attached is with the foam in place, without the foam it’s actually linear to 20kHz
 

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It seems this has a great potential, especially considering the (relative) simplicity. Perhaps a lower-DI waveguide could be used.
Again, congratulations to a great achievement.

- Did you consider making the midrange a cardioid (with side ports) to increase the DI in the mid band? That would be an insane construction for its size.

[...] Then the compression driver is more capable but as you said bigger throat size.
I don't think you would need a more capable driver if you can keep the XO this high without any issues...
 
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- Did you consider making the midrange a cardioid (with side ports) to increase the DI in the mid band? That would be an insane construction for its size.
Absolutely, it’s been on my mind since the D&D 8c showed its controlled dispersion. And now I got a nice platform to play with.
Toxic traits make one think that I can do it equally good.

I also considered making a version of linkwitz lx-mini that would simply offset the driver and waveguide out from the back chamber. And fill it completely with melamine foam.

But first a simple removal of the back chamber and measure the effect of the midrange in an open back configuration.
 
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What happen when you scale down the st-260 and ad a roundish back chamber/cabinet and taps for a 4” midrange cone?
I know..

I used the st-260 scaled it down to a 12mm throat, modified the back and fitted it on a cheap 4” coaxial from Thomann in house brand The Box.
The coaxial has a cylindrical hole thru the midrange motor structure and originally a small horn for the tiny compression driver.

I added ~ 4cm open cell foam in the cylindrical part near the throat of the waveguide that cleaned up some peaks and valleys for both of the drivers frequency response .
And from yesterdays measurement. I think this fun experiment can become something useful. Or not, it’s all for fun anyway.

I always wanted to try Danley’ solution for adding a coaxial as part of a synergy horn but my printer bed is limited. Ergo I fiddled with a tiny coaxial and accept the limitations.

I apologize for the snapshots of the measurement but the time ran out. The battery on the laptop died as I was about to hear the first actual music. Literally pushed play and it died..

Side note: it’s only a 6ms window, no smoothing. Bad measurement conditions.
This is so cool! Congratulations!