diyAudio

diyAudio (https://www.diyaudio.com/forums/index.php)
-   Multi-Way (https://www.diyaudio.com/forums/multi-way/)
-   -   Acoustic Horn Design The Easy Way (Ath4) (https://www.diyaudio.com/forums/multi-way/338806-acoustic-horn-design-easy-ath4.html)

mabat 21st July 2019 10:29 AM

To all users -

I have written this several times but I will repeat as it is really crucial (for now and the current release 4.3.4):
You have to set the Out.DestDir item in your script files to some (already existing *) directory in your system. Using a full path (e.g. "D:\Acoustics\ATH_results") is the best. There will be stored your results. Otherwise the output files could be mixed up or not generated at all.

* already existing means that this directory must exist when ath4 is launched, i.e. it is not created automatically. You can create it beforehand by yourself of course :)

Gaga 21st July 2019 11:03 AM

Hi Patrick,

Quote:

Here's what I came up with:

3D Modeling Tips and Tricks
This is great! Thanks a lot for your detailed description. I'll try to use your approach for my next sims...

Quote:

That is great, Patrick (or John). The first step, i.e. converting STL to solid, can also be easily automated. I'll definitely do that, to generate the STL as solid right away, I just have been quite busy for the last several months so not much work has been done on ath4.
I'd definitely appreciate this. Thanks again for your great work!

BW,
Christoph

Patrick Bateman 21st July 2019 06:21 PM

Quote:

Originally Posted by mabat (https://www.diyaudio.com/forums/multi-way/338806-acoustic-horn-design-easy-ath4-post5858623.html#post5858623)
That is great, Patrick (or John). The first step, i.e. converting STL to solid, can also be easily automated. I'll definitely do that, to generate the STL as solid right away, I just have been quite busy for the last several months so not much work has been done on ath4.

The crazy thing, is that I could SWEAR that I was able to get meshmixer to close that waveguide. Last month in meshmixer I used some combination of settings in meshmixer, and it simply "filled in" the inside of the waveguide.

For the life of me, I couldn't get it to do that yesterday.

It's not the end of the world; extruding the shape gets the job done too, but it's messier.

4real 20th August 2019 11:09 AM

Really cool stuff this! I even managed to run it on a Mac :D

Did some quick and dirty experiment with a 80x40 horn:

https://www.diyaudio.com/forums/atta...5-19-58-21-jpg
https://www.diyaudio.com/forums/atta...5-20-01-33-jpg

One question though: is there an easy way to control the size of the horn? What I did now is tweak the depth and angles to get in the ballpark of the size I'd like, but that limits me to a specific range of angles. Let's say I want to make a 2:1 (w:h) sized horn that is 90x90 deg. Can the tool do that for me?

mabat 20th August 2019 12:46 PM

I've thought for a long time about a way how to specify the shape and the size. Finally I settled for exactly the way that you just descried - it may seem a bit odd at first but it gives you the most freedom. It could be done the other way, i.e. to set the mouth dimensions fixed and calculate the other parameters but that would mean something would need to be standardized in some way. I may re-think for the next release. Maybe I will make it an option.

BTW, you should probably increase the number of angular segments. It can be much finer than that (but the BEM analysis will take much longer).


- For anyone interested in the underlying principles of how it is really done, I can recommend the Appendix A in the User Guise. There's the math.

http://www.at-horns.eu/release/Ath4_UserGuide.pdf

4real 20th August 2019 12:48 PM

It's fine to use the trail and error method, as long as I know what knobs to turn. So how then do I go about making the horn in my last question? Or even the reverse: a (almost) square 60x40 horn?

mabat 20th August 2019 01:12 PM

That's not possible at the moment, I'm afraid, because you must enter the angles first. Together with the depth (and other variables) this will lead to some mouth dimensions. You see, when the mouth is squarish, it's strange to have the two coverage angles different, and vice versa.

I see a simple solution however. For a rectangular horn (i.e. for Shape = raw2rect), I will make parameters available for any target mouth dimensions you may like (now it is taken from the raw shape's width and height before the final transformation).

Stay tuned :)

jzagaja 20th August 2019 01:14 PM

Do you think Abec could do phase plug sim too?

mabat 20th August 2019 01:21 PM

I don't know. I don't know if the "ordinary" acouctics is all that is involved in the phase plugs. You can model that geometry down to a diaphragm, of course you can, and ABEC will calculate something (I suppose) but I have no clue about the results validity.

jzagaja 20th August 2019 01:32 PM

I'm think about 3D spiral phase plug "salt shaker". Not yet finnished sketching. Looking for math formula to speed up.


All times are GMT. The time now is 05:07 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio

Wiki