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Old 31st March 2013, 04:54 PM   #5921
gedlee is offline gedlee  United States
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Quote:
Originally Posted by Kindhornman View Post
Earl,
I haven't read your book but would be very interested in that. Is that the book on transducers on your website also including your waveguide theory and measurement or is that a separate writing? I see you have a paper on horn theory, but what of your AES papers or pre-prints. How do I get my hands on those papers without going down to UCLA and looking through the stacks?
The book has a entire chapter on waveguides. You can buy the book or go to Geddes on Audio and down load the pdfs for free.

The papers and preprints are all available from the AES as single copies, but you would have to pay for them. Otherwise go to the library.
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Old 31st March 2013, 05:15 PM   #5922
gedlee is offline gedlee  United States
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Originally Posted by Kolbrek View Post
I would assume the conical/spherical segment method would converge faster, but it is limited to axisymmetric waveguides. I'm currently working on applying the stepped method to rectangular waveguides, and I can then use the same framework.

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Bjørn
I see rectangular waveguides as a bad choice since all compression drivers have circular apertures. There will always be a problem going from round to rectangular. There is no good way to do that. Circular to elliptical is doable (I have waveguides that do that), but not circular to rectangular. That's why I never pursued rectangular waveguides.

There are elliptical solutions as well, they are called Neumann Functions and the same techniques used for the conical spherical can be done in the elliptical case. There are FORTRAN routines that calculate these elliptical functions. I don't know about C++.
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Old 31st March 2013, 05:30 PM   #5923
winslow is offline winslow  United States
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What would you do in a high performance car audio system?
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Old 31st March 2013, 05:35 PM   #5924
gedlee is offline gedlee  United States
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I have tried that before, I did not find any good solutions. Cars are not good places for good audio systems.

Recent studies that I have seen found that the difference between a "normal" car audio system and a optional Hi-end audio system are shrinking to the point of very small advantage for the Hi-end systems. Not what Bose or Harman marketing want you to think but something that the car companies are coming to realize. There is not much room in a car for a real product differentiation based on performance. These systems are becoming a commodity.
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Old 31st March 2013, 06:30 PM   #5925
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Earl,
thank you for the fact you have your book as pdf files on your website. I rather like real books so I am sure I will buy the book here at some point, I don't particularly like reading on a computer screen and it is nice to be able to change pages at will. The cost to print the book on my printer would probably not save much at the cost of ink cartridges and they just aren't the same as a bound book.

In your preprints and AES Journal papers is there information that would not be in your book, or is it all inclusive?
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Old 31st March 2013, 06:35 PM   #5926
soongsc is offline soongsc  Taiwan
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Quote:
Originally Posted by gedlee View Post
The book has a entire chapter on waveguides. You can buy the book or go to Geddes on Audio and down load the pdfs for free.

The papers and preprints are all available from the AES as single copies, but you would have to pay for them. Otherwise go to the library.
Looks like I have some reading ahead of me. Thanks.
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Old 31st March 2013, 06:38 PM   #5927
gedlee is offline gedlee  United States
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Quote:
Originally Posted by Kindhornman View Post
Earl,
thank you for the fact you have your book as pdf files on your website. I rather like real books so I am sure I will buy the book here at some point, I don't particularly like reading on a computer screen and it is nice to be able to change pages at will. The cost to print the book on my printer would probably not save much at the cost of ink cartridges and they just aren't the same as a bound book.

In your preprints and AES Journal papers is there information that would not be in your book, or is it all inclusive?
Chapter 6 in my book is IMO the most complete coverage on waveguides that I know of in one place. Start there and if you need more information then go for the papers.
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Old 31st March 2013, 06:42 PM   #5928
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Earl,
I am not so sure that you can not create a mathematical method of shape changing from a round cross section to a rectangular one, but the real question would become why would anyone want to do that on purpose? It is not a shape that a waveform is going to want to follow or remain attached to, the corners and parallel sides are going to be a problem, that has always been the failing of radial horns using classical designs. The break point where the throat and the angular flare join is always a compromised solution and this is what I think led us both down the path we both have taken. There is no mathematical solution to that conjunction of the throat and flare in a standard radial horn, this is going to be a major creator of your homs distortion from what I have just started to look at from your work. I don't understand why people can not see the correlation between this and fluid dynamics and shape changes?
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Old 31st March 2013, 07:12 PM   #5929
gedlee is offline gedlee  United States
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In a diffraction horn going from round to rectangular is a no-brainer, but if one is trying to minimize diffraction, I don't see how it can be done with a rectangular waveguide. Unless one develops a square aperature phase plug (like in one of my patents).
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Old 31st March 2013, 07:15 PM   #5930
Pano is offline Pano  United States
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Do you see square as much different from rectangular - for the purpose of waveguides?
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