Acoustic Horn Design – The Easy Way (Ath4)

This could be interesting as well.

20684_full.png
 
The combination of Matlab/Comsol works fine. I implemented something similar (I am not acociated with the Author of the aforementioned paper) by myself and did show it previusly here in this topic.



My current implementation takes almost 2 Weeks for an optimisation in two domensions. Which is part due to my Hardware (8 core Rayzen) and part due to Comsol as the calculation and post processing is rather slow (k-wave manages some higher frequency stuff in fraction of what Comsol needs but does not support objects in the frequency domain interface...). I tried to find other frequency domain solvers that work directly in Matlab and maybe even have GPU support but no luck so far (in finding something that I actually understand how to interface...)


Also, I do not use a CAD Programm currently ( My goal is to fully run it in Matlab) but that may Change again as I am having trouble post processing the finished Model.
 

Attachments

  • US20200077180A1-20200305-D00004.png
    US20200077180A1-20200305-D00004.png
    129.3 KB · Views: 348
  • US20200077180A1-20200305-D00011_Horizontal.png
    US20200077180A1-20200305-D00011_Horizontal.png
    170.5 KB · Views: 351
  • US20200077180A1-20200305-D00013_Horizontal.png
    US20200077180A1-20200305-D00013_Horizontal.png
    203.6 KB · Views: 350
  • US20200077180A1-20200305-D00015_Horizontal.png
    US20200077180A1-20200305-D00015_Horizontal.png
    230.1 KB · Views: 348
The rectal guide was discussed earlier in this thread. Now it is also patented by Samsung Electronics.
BTW, that shape is simply a result of the way they allowed the profile curves to change, which was very basic and still quite limited rule, IMHO (just bezier cubics, IIRC). So it is optimized in a sense that it may perform "best" within the limitations given. Which is of course true for any such optimization. Anyway, good luck with that! :)
 
BTW, that shape is simply a result of the way they allowed the profile curves to change, which was very basic and still quite limited rule, IMHO (just bezier cubics, IIRC). So it is optimized in a sense that it may perform "best" within the limitations given. Which is of course true for any such optimization. Anyway, good luck with that! :)

Agreed. In the last 10 years we have seen horns with knuckles, mumbs, ridges and so on. Neither of these features has resulted in an evolutionary performance improvement.
 
Someone is confused, maybe me!

Ro808 stated:
Neither of these features has resulted in an evolutionary performance improvement.

Which, to me, means that these features have not resulted in any improvements.

but Mabat says:
No I really tried to imagine an evolutionary performance improvement in horns but really can't think of any.

Which says, to me, the exact same thing.

Do you guys agree or disagree? It's not clear.

Interferences? Well, I "could" imagine a driver+horn combo reaching a pure spherical wavefront - that would be an improvement!
I too was unclear what was meant by "interference".
And yes a "pure spherical wavefront" would be great, but you should also state that this should occur across the bandwidth. A spherical wavefront at one frequency is not so difficult, but at all frequencies, it is likely impossible.
 
Last edited:
And that would be...?

I suppose, revolutionary improvement would mean

* Flat acoustic loading from 200-300Hz and up to the last audio octave (e.g. like Heavise or step Sigmoid function).
* Constant directivity in the same frequency range. (I suppose beamwidth of -+(20-30)° in all directions would be ok, at least for home audio).
*Horn-related acoustic nonlinearities would be comparable to that of the direct radiator.
*Perhaps, some kind of numerical criterion should specify a minimum value of HOMs amount.

"Revolutionary design" should improve all the point above at the same time. But as we know, "the horn reality" is completely different. Numerical optimisation helps to find a certain balance of contradictory horn parameters :).
 
Last edited: