Acoustic Horn Design – The Easy Way (Ath4)

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This is about as flat as reasonably possible with a 2" throat (the same picture as before) -

1682446612807.png
1682446667149.png


1682447025734.png
 
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In any event, I just measured the driver and the diameter is 38.1 mm.
Here you go - STEP file attached. Beware it's only a surface (not solid) but I know it's possible to continue somehow, as I provided such data in the past and the people were able to use that.

Tritonia, 38.1mm/0deg throat: https://a360.co/3n6cH0I
 

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Hi mabat,

thank you very much.

I was able to open the file in Solidworks, but Solidworks indicates faulty face and gap in-between faces. When I heal them, I Solidworks cannot recognize any features so I cannot edit the part so that I cannot split it for printing.

I will keep working on it as I really want one. Worse comes to worst, I will have to learn Fusion. :cry:

Kindest regards,

M
 
What general rules do you follow when matching a driver diameter to a waveguide? For example, is it clear by looking at this report which driver diameter you'd want to use or is it not that straightforward? (assuming freestanding horn rather than two-way enclosure)

B&C DE111 recommends 1.2kHz 12dB/oct or higher crossover on B&C ME 45 horn
Device width x height = 221.07 x 18.00 mm (8.703 x 0.709")
Device length = 62.22 mm (2.450")


46_8inch.png
 
Hi mabat,

thank you, thank you, thank you.

I was able to create the wave-guide ready for printing.

Tritonia_SLDPRT.jpg


Since I am on the roll :D and the mouth ends perpendicular to the axis, what do you think if I added a four inch radius rollback on each of the mouth edges? I have a faint recollection that you had simulated something along these lines, no?

Kindest regards,

M
 
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What general rules do you follow when matching a driver diameter to a waveguide? For example, is it clear by looking at this report which driver diameter you'd want to use or is it not that straightforward? (assuming freestanding horn rather than two-way enclosure)
You mean a woofer diameter? I don't think it's clear just by looking at the report. First, you have some capabilities of a HF driver used, which basically determine how low it can be used with that WG. Then you decide how big LF driver to use, so both match nicely around the chosen crossover frequency. It takes some experience I guess. Using a diameter comparable to that of waveguide should be a pretty safe bet in most cases.
 
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Yes, this particular one is. So obviously, with a R-OSSE profile one can create all from a straight conical, OS to exponential and everything in between (and then there's always an inherently smooth roll back at the mouth).

With an optimization algorithm, I believe one could generate a shape for any DI slope (within reasonable limits) desired.
 
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No doubt, it can be worse. This is for a nominal cutoff ~ 300 Hz:

R=346, r0=25, a0=5.3, a=18, k=13.2, r=0.81, b=0, m=0.7, q=3.02

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ATH-BIG-EXP-L.png


At least it doesn't resonate.
This way it's straightforward to make e.g. a horn with an exponential vertical and an OS horizontal contour...
 
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