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

Ro808 20th January 2021 01:34 AM

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Quote:

Originally Posted by Kevmoso (https://www.diyaudio.com/forums/multi-way/338806-acoustic-horn-design-easy-ath4-post6496109.html#post6496109)
Looks like standard 3d printing pattern.
Here is one. Maybe not as pretty but the pattern is the same.
Nautilus speaker by bberkel - Thingiverse

Natually, the printing pattern is similar, though the material is completely different.

To me, this material also 'looks' very suitable. Perhaps it's the same as shown before, but a different color.

Kevmoso 20th January 2021 02:30 AM

Quote:

Originally Posted by Ro808 (https://www.diyaudio.com/forums/multi-way/338806-acoustic-horn-design-easy-ath4-post6496163.html#post6496163)
Natually, the printing pattern is similar, though the material is completely different.

To me, this material also 'looks' very suitable. Perhaps it's the same as shown before, but a different color.

That just looks like rustoleum stone paint...
American Accents(R) Decorative Finishes Stone Spray Paint Product Page

Ro808 20th January 2021 02:53 AM

Yep, it's stone spray.

https://i.pinimg.com/originals/ec/e5...e3b9ffccc5.jpg

mabat 20th January 2021 04:17 AM

Quote:

Originally Posted by Ro808 (https://www.diyaudio.com/forums/multi-way/338806-acoustic-horn-design-easy-ath4-post6496162.html#post6496162)
The intention, purpose if you wish, of JMLC's method is to calculate/design horns that provide the smallest reflectance and diffraction, a smooth pressure field and subsequently (due to the 'natural' expansion) generate a very low amount of HOMs.

"When calculating a Le Cléac'h horn, there is nothing special in my spreadsheets or software related to the curvature of the mouth. The curved back mouth is not intended nor provoked, it is the result of the "design by nature" of the horn."

It seems from the results gathered so far that the actual contribution of HOMs (inherent to a profile) will be generally very low, at least up to a rather high frequency. I'm more and more convinced that what is observed as "disruption of pressure field" is almost always caused by a suboptimal mouth termination. Take any shape of the Salmon horn family and make a smooth termination e.g. via a clothoid and I'm sure it will all behave virtually the same. That's the reason I said it is "nothing more" than a smoothly terminated exponential horn. Because in my view there's really nothing more to it. I still may be missing something, but then show me.


No stone sprays, please :)

David McBean 20th January 2021 05:52 AM

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Quote:

Originally Posted by mabat (https://www.diyaudio.com/forums/multi-way/338806-acoustic-horn-design-easy-ath4-post6495957.html#post6495957)
So, what was the intention? :)

The intention was to be able to generate a horn profile given a defined isophase wavefront area expansion rate. Jean-Michel assumed a hyperbolic-exponential expansion, but it could just as easily been have something else (eg. conical, exponential, parabolic). It was a brilliant piece of work, freely shared, and arguably one of the very few genuine advances in acoustical horn design in the last fifty years.

mabat 20th January 2021 05:56 AM

OK, whatever the intention was, what's the merit?

David McBean 20th January 2021 06:35 AM

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Quote:

Originally Posted by mabat (https://www.diyaudio.com/forums/multi-way/338806-acoustic-horn-design-easy-ath4-post6496320.html#post6496320)
what's the merit?

For one thing, a superior horn throat acoustical impedance characteristic loading the driver, due to the controlled expansion rate and the better impedance matching at the horn mouth resulting from the rollover inherent in the Le Cléac'h generated profile.

mabat 20th January 2021 06:36 AM

When I asked about the intention, I of course was interested in this claim: "... but they clearly work as intended." Clearly I would like to understand what was the intention and what was verified. The smoothness of the polars? Is that it?

Frankly, I see absolutely nothing special about the acoustical impedace you show. Somewhat suboptimal, at best.

David McBean 20th January 2021 07:59 AM

Quote:

Originally Posted by mabat (https://www.diyaudio.com/forums/multi-way/338806-acoustic-horn-design-easy-ath4-post6496337.html#post6496337)
Frankly, I see absolutely nothing special about the acoustical impedace you show. Somewhat suboptimal, at best.

I bow to your superior knowledge in such matters.

mabat 20th January 2021 08:47 AM

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Well I would at least try it without such pronounced reflection.


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