Bill you have such a tactful way about you it is a wonder I respond at all.
I never criticized, Morse or Vibration and Sound, I use that book all the time. But Morse and Feshbach (note - a completely different book) is not modern physics and its math approach is obsolete in that field. (Although that math is useful in some fields of engineering, but there are probably better texts even there.)
And Einstein's problems with Tensors - back 100 years ago - have nothing to do with this discussion, except that all physics is done in tensors these days and Einstein found them useful (necessary) in his work. Although originally he just used matrices and the Lorentz transform before he realize the power of the tensor formulation. Tensors were new enough in his time that he needed to develop a way to write them and even today "Einstein Notation" survives.
Somehow you seem to feel that listing a few references lets you be rude.
Shape optimizations do work well as some researcher in Aus showed (can't recall his name). Curious how close his "optimum" turned out to be to what I found with just math some twenty years prior. He used the techniques that I described in my book (more than ten years ago) by the way.
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Your disrespect does not really warrant this, but:
An EC waveguide mouth will couple well to a PS waveguides throat (but it is not exact), but of all the other variations that you claim work and that you claim I said, this is the only one that is actually valid. The EC has a square throat however and that's why I did my patent on different phase plugs that could adapt to different geometries - most notably the circular one of most compression drivers. There is no coordinate system that goes from round to square, but this could be done in the phase plug. A ribbon would not need the phase plug as it could driver the EC throat directly.
If you are going to parrot someone at least get it right. 😉
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I agree with you, 100%. This was the subject of one of my threads too:
I have always felt that uniform directivity was important, at least since the first few loudspeaker experiements I tried as a young man. But I found early on that constant directivity horns sounded spitty and went back to older radial horns instead. Their beamwidth wasn't as constant, but they had good horizontals, which was most important to me and their response was smooth.
To me, modern waveguides are an evolution of that approach, at least the waveguides I like are anyway. But frankly, many of the new waveguides don't provide very smooth response, and they measure and sound similar to the older CD horns. So I think finding the right set of compromises is important for good sound quality.
That is not what you said in Tulsa, and it is not what you said in your patent. You can say it now, but that is like trying to re-write history.
You and I discussed the possibility of you designing a horn and I would produce it. But as the months went by, I realized that a working relationship with you would be difficult, so I decided against that. I designed my own waveguide/horn instead.
Frankly, by that time, I was swayed more by the fact that these shapes were used in other disciplines than the fact that you adopted them in audio. As much as your credentials seemed impressive, I had begun to lose faith in your assessments. Sorry, I still have always given you credit for bringing these devices based on elliptical coordinate systems to my attention, but I think what swayed me more were the OS/PS/EC devices used in other fields.
I will quote you again, mostly out of sheer amazement that youy think you can say to this forum that this isn't really what you meant when you wrote it:
"The throat of an EC waveguide can be feed by several varieties of sources. First, an actual rectangular source could be used, a phase plug could be made which had a square outlet instead of the usual round one, or a round source could also simply feed the square opening. It is also quite reasonable to assume that a gradual transition from the normal round outlet of a compression driver or speaker to the square section of the EC Waveguide would function without undue degradation of the devices performance, so long as the same cross sectional areas are maintained or grow at a slow rate."
To tell the truth, when I saw your patent I knew that out of respect for your work in the field, I should not challenge it but it had been applied far too late. There were already products in the field that used those shapes. I knew that was true because I had made one of them.
So I dunno, Earl. Sometimes I cannot believe the things I see you saying. This is one of those times.
Addition:
*** It might be possible to simply mirror one "triangle" - ex. bottom "triangle" complete, mirror to top position.
This video 2:30 in:
123D Design Tutorial - Construct: Extrude, Sweep, Revolve, Loft - YouTube
Shows the loft function. When the disk is "copied" and moved up - that movement up is adding an additional plane.
This older video talks about planes a bit better (in conjunction with loft):
Autodesk 123D beta 9 Loft Feature - YouTube
This thread will take a brief pause so that we may have a break from the Wayne & Earl Show.Gentlemen, take the "He said, She said" somewhere else.
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