Not very oblique... (my 1st Apple LaserWriter +, all $14.500 of it, was named Fnord)
Highly recommended reading... one should also read the sequel, Schrodinger's Cat Triology (by the way, this last the inspiration of the now gone Texas Forum)
dave
Hello,
Waveguide is a means to transfer the signal energy of the wavefield from one place to the other. It's a 'guide' in order to keep the energy inside not letting it to radiate.
Horn is the outdoor of the waveguide, a 'wave transformer' making it possible for the wave to exit the waveguide.
😀 Other usage of the terms is purely marketing bś
- Elias
Waveguide is a means to transfer the signal energy of the wavefield from one place to the other. It's a 'guide' in order to keep the energy inside not letting it to radiate.
Horn is the outdoor of the waveguide, a 'wave transformer' making it possible for the wave to exit the waveguide.
An externally hosted image should be here but it was not working when we last tested it.
😀 Other usage of the terms is purely marketing bś
- Elias
Thats microwave stuff and doesn't apply to "acoustics". WHen I introduced the term, the word "Acoustic" was an adjective.
Wouldn't that be Re-introduced?
Waveguide as Elias has described it has been around for eons. Nowadays they seem to call them throat adapters. Or in the case of the Altec welded horns it was the section between the mounting flange (round) and where it becomes a horn (rectangular)
Waveguide as Elias has described it has been around for eons. Nowadays they seem to call them throat adapters. Or in the case of the Altec welded horns it was the section between the mounting flange (round) and where it becomes a horn (rectangular)
Actually it's rather easy.
*Wave* *Guide*
Guiding waves, or directing waves. Limiting dispersion by physical means.
Of course limiting dispersion *can* also include gain (..assuming the guide doesn't absorb the wave). In fact it *usually* includes gain.
If the primary reason to guide an acoustic wave is to increase gain then it's a Horn. (..originally derived by bearing a similarity to animal "horns".)
If the primary reason to guide an acoustic wave is to limit dispersion ("shape" it), then it's a Waveguide.
Functionally all Horns are Waveguides, but not all Waveguides are Horns. You can have a Waveguide that absorbs and does not increase gain, but all Horns rely on "compressing" the dispersion pattern to increase gain in a particular direction.
Discussions of mathematical equations are irrelevant, the above concepts pre-date them - and not only were, but are their common meaning.
As far as *reproduced* sound.. at the beginning the emphasis was on gain. In the mid 1930's the emphasis changed to more specific dispersion patterns (..with gain) in theaters so that the sound was directed to all viewers.
None of those are acoustic devices, they are all microwave RF devices. Yes the term has been arround for a long time in that context, but I do not think that you can find its usage in the context of acoustic devices prior to my 1990 paper. I did not just randomly pick that term. It was choosen because it had not previously been used in acoustics. Not that I could find at least.
I don't think so. Check out the patent dates. They may nave been concurent with me, but certainly not preceeding me.
First you say 1990 paper, then talking about patent dates.. So, when was the exact day you introduced the term "waveguide" in the context of "acoustics"?
- Elias
Well, Bose introduced a commercial product involving the term "acoustic waveguide" in 1984 I think.
You cannot be seriously claiming the rights for inventing the term "acoustic waveguide". Here's a paper about "acoustic waveguides" from 1964:
Acoustic Waveguides
And here's a thousand more pre historic "acoustic waveguides"
pre gedlee acoustic waveguides
- Elias
I did not claim to have invented the word I claim that I first used it in this context. I was aware of the use of the term in microwaves, underwater sound and in ultrasonic welding, but the devices that I was considering were always called "horns" prior to my usage.
Earl, not hear to argue with you but when Altec was using the term in the 50's to describe the throat adapters and the initial throat part of the two piece cast horns, I find it interesting that you wish to claim that you were the first. Also I'm not sure what you mean by microwaves. As far as I know, the Altec horns were only ever used for music. 😉
HI Cal
I don't recal Altec using the term "Waveguides" to refer to horns. Do you have a reference for that? I don't think that you were around then - although I was - so I am not sure where you would have seen this.
Really, there may have been instances of the terms usage prior to 1990, but in the context of this thread it was the usage in my 1990 paper that is being discussed here. In 1990 it was not being used in any context even close to what that paper was about.
I don't recal Altec using the term "Waveguides" to refer to horns. Do you have a reference for that? I don't think that you were around then - although I was - so I am not sure where you would have seen this.
Really, there may have been instances of the terms usage prior to 1990, but in the context of this thread it was the usage in my 1990 paper that is being discussed here. In 1990 it was not being used in any context even close to what that paper was about.
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Morfey's Dictionary of Acoustics (2000) defines an acoustic horn as "a passive device in the form of a hard-walled tapering acoustic waveguide of finite length. When a volume-velocity driver is placed at the narrow end or throat of the horn, the acoustic coupling between the transducer and the surrounding medium is enhanced. The wide end or mouth is usually arranged to be large enough (in comparison to the acoustic wavelength) that most of the incident energy arriving at the mouth is transmitted into the surrounding medium, with the result that the horn also produces a directional far-field response."
Thus, by this definition, all acoustic horns may be considered as being acoustic waveguides. 🙂
"For a more general description, also applicable to solid horns, see HORN."
Thus, by this definition, all acoustic horns may be considered as being acoustic waveguides. 🙂
"For a more general description, also applicable to solid horns, see HORN."
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They may have CALLED it an acoustic waveguide, but it wasn't. 😉
"In 1987 Drs. Bose and Short were co-named 'Inventor of the Year' for developing acoustic waveguide speaker technology. For some, that would signify the end of the journey. At Bose, it was merely the beginning."
Applied Learning - Waveguide Technology - Bose Learning Center
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