..it is, but it's also the logic that supports the conclusion - and the conclusion still remains:
The OP's purchase is primarily a waveguide both by design and almost certainly by use. (..after all, how many designers/users here are looking for more gain from their compression driver?)
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Actually I don't get "A equals B" from you (il)logic statement.
So - you are sure its not up to *you* to look for some professional help ???
When is a waveguide not guiding a wave? - when the wave is suppressed or blocked from ever occurring.
Michael
So - you are sure its not up to *you* to look for some professional help ???
Michael
Oh no, that I've participated this far is surely a sign of mental instability.
..and certainly made worse by the fact that I'm fairly certain that the OP (mondogenerator), did not want this lengthy analysis from his fairly basic question.
Yep - finally *you got it* !
(at least regarding the first half of you statement)
Michael
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It is largely a semantic issues (as I said in post #2) but there are some important distinctions to be made.
If we are talking about the acoustic load presented to the driver, the equivalent circuit of a device with expanding area, a means of increasing efficiency, a device with a throat of reduced area vs. the drivers diaphragm, if we are looking at radiated power independent of angle or efficiency vs. frequency, then these are characteristics of the classic horn.
If we are concerned with wall contours and how they determine beamwidth, polar pattern or directivity index, then we are talking about the device as a waveguide.
Of course, every device we can think of has both characteristics and we can call it with either name and not be incorrect.
I still prefer to call flares on tweeters waveguides rather than horns, but thats just me.
David S.
If we are talking about the acoustic load presented to the driver, the equivalent circuit of a device with expanding area, a means of increasing efficiency, a device with a throat of reduced area vs. the drivers diaphragm, if we are looking at radiated power independent of angle or efficiency vs. frequency, then these are characteristics of the classic horn.
If we are concerned with wall contours and how they determine beamwidth, polar pattern or directivity index, then we are talking about the device as a waveguide.
Of course, every device we can think of has both characteristics and we can call it with either name and not be incorrect.
I still prefer to call flares on tweeters waveguides rather than horns, but thats just me.
David S.
The OP isnt looking for discussion on felt rings either
Within the context of what the OP is asking isnt it just a good idea to keep it a little simplistic and say that all devices like that simply some sort of horn?
I have yet to see a CD that is not mounted to something that isnt in the horn category.
That is an interesting point because in that case I can see that as a waveguide and not a horn at all. I think that would answer my question "What waveguides are not horns".
It's both a horn and a waveguide. They are the same thing. It's like calling a couch a sofa. It appears to be a nice little horn.
WOW you guys have been busy!
I DIDNT EXPECT THIS MUCH RESPONSE ALREADY
i have to be referee and say i agree with everyone! the issue of semantics is well and truely alive in this forum (as i have been involved in similar discussions....)
if i REALLY wanted to split hairs i would agree with doug...waveguide came from RADAR, and i would also say fibre-optic cable is also a waveguide....taking these 2 examples, i would say an acoustic waveguide would emit a cylindrical radiation pattern versus a conical one from a horn? perhaps im overthinking this
anyway enough of me being pedantic...
i will say that the apperance is one of a waveguide, and less of a typical horn, due to the depth. however the depth is greater than i have seen many waveguides (like Zaphs waveguide for dome tweeter, and the ESP ones), which leads me to believe it is somewhere in between, in the grey area everyone disagrees over.... a bit like the Falklands a few years back.
i have used it to load a visaton g20sc 20mm dome tweeter. there was most definately SOME gain, both around Fs and above, probably between 1k and 5k, and that VHF seemed recessed or maybe just better damped (excursion?).
the sound is pretty good, SOME gain but largely just loading, as the FR isnt as flat as the tweeter alone, but thats offset by the 'nice' sound of VHFs.
the only pity is the depth, for alignment of acoustic depths between the guide and woofers i have currently. the mouth is an ideal size to match with a 5-6" driver, but the depth is such that the tweeter is behind the woofer centre, perhaps more than with 'normal' flush mounting. but hey! they were a massive bargain!
cheers for all the contributions guys! any other ideas most welcome!
I DIDNT EXPECT THIS MUCH RESPONSE ALREADY
i have to be referee and say i agree with everyone! the issue of semantics is well and truely alive in this forum (as i have been involved in similar discussions....)
if i REALLY wanted to split hairs i would agree with doug...waveguide came from RADAR, and i would also say fibre-optic cable is also a waveguide....taking these 2 examples, i would say an acoustic waveguide would emit a cylindrical radiation pattern versus a conical one from a horn? perhaps im overthinking this
anyway enough of me being pedantic...
i will say that the apperance is one of a waveguide, and less of a typical horn, due to the depth. however the depth is greater than i have seen many waveguides (like Zaphs waveguide for dome tweeter, and the ESP ones), which leads me to believe it is somewhere in between, in the grey area everyone disagrees over.... a bit like the Falklands a few years back.
i have used it to load a visaton g20sc 20mm dome tweeter. there was most definately SOME gain, both around Fs and above, probably between 1k and 5k, and that VHF seemed recessed or maybe just better damped (excursion?).
the sound is pretty good, SOME gain but largely just loading, as the FR isnt as flat as the tweeter alone, but thats offset by the 'nice' sound of VHFs.
the only pity is the depth, for alignment of acoustic depths between the guide and woofers i have currently. the mouth is an ideal size to match with a 5-6" driver, but the depth is such that the tweeter is behind the woofer centre, perhaps more than with 'normal' flush mounting. but hey! they were a massive bargain!
cheers for all the contributions guys! any other ideas most welcome!
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Acoustic Waveguide vs. Acoustic Horn
Whether an item is Christened "Waveguide" or "Horn" depends on where design emphasis is being placed. In this setting the following definitions may be used to distinguish between the two.
Acoustic Waveguide
A typical acoustical waveguide consists of a pipe, conduit or similar bounded pathway, sometimes incorporating bends, used to guide and transport undulatory energy (waves) between its end-points, unchanged, except for direction. Consistent with this objective, walls remain essentially parallel. Also its impedance to wave flow is constant throughout its length. Typical wave guides include ear cannels, stethoscope tubes, impedance tubes, loudspeaker transmission line ducts, organ pipes, and the flute.
Acoustic Horn
A typical acoustic horn, on the other hand, is a disperser or collector of undulatory energy (waves). Its purpose focuses on changing the shape and intensity of the waves that pass through it. For this purpose its walls are flared or tapered. Here its impedance to wave flow is transformed from high at its throat, to low at its mouth. Examples of acoustic horns include those associated with loudspeaker drivers, sirens, and musical instruments (brass and woodwind).
These definitions, like all others, are imperfect due their brevity, and other linguistic limitations imposed; however the distinctions they facilitate are important to discourse in the context of acoustics in general as well loudspeaker design in specificity.
Regards,
WHG
Whether an item is Christened "Waveguide" or "Horn" depends on where design emphasis is being placed. In this setting the following definitions may be used to distinguish between the two.
Acoustic Waveguide
A typical acoustical waveguide consists of a pipe, conduit or similar bounded pathway, sometimes incorporating bends, used to guide and transport undulatory energy (waves) between its end-points, unchanged, except for direction. Consistent with this objective, walls remain essentially parallel. Also its impedance to wave flow is constant throughout its length. Typical wave guides include ear cannels, stethoscope tubes, impedance tubes, loudspeaker transmission line ducts, organ pipes, and the flute.
Acoustic Horn
A typical acoustic horn, on the other hand, is a disperser or collector of undulatory energy (waves). Its purpose focuses on changing the shape and intensity of the waves that pass through it. For this purpose its walls are flared or tapered. Here its impedance to wave flow is transformed from high at its throat, to low at its mouth. Examples of acoustic horns include those associated with loudspeaker drivers, sirens, and musical instruments (brass and woodwind).
These definitions, like all others, are imperfect due their brevity, and other linguistic limitations imposed; however the distinctions they facilitate are important to discourse in the context of acoustics in general as well loudspeaker design in specificity.
Regards,
WHG
essentially EXACTLY what i said...but thanks for confirming my thoughts, and also, perhaps as a side effect, my semantic apathy.
I wonder then if this means Geddes 'Waveguides', radiate a cylindrical shaft of sound, rather than a cone? or rather a narrower cone than most 'horns'.....
If you say so - lets go ahead...
As much as one could have agreed to that definition *before* Earl Geddes has messed up this term (waveguide) by popularizing it for his OS boundary shaped horns (out of commercial interests), the much one must disagree *nowadays*
The original question in this thread shows exactly the disorientation that has its roots in such "sales speak" - hence the impression of a lot of semantic hairsplitting
From the mere technical side of underlaying principles its all about *diffraction* and its alignment in 3D space - be it called waveguide of be it called horn.
For absorptive materials one *could* stretch the term "diffraction allignment device" as well (as said above) - but - as the diffraction control effect by absorptive materials (the towel trick for example) is rather a side effect it would / should not be used as such - at least where I come from.
One would instead say that :
"Absorptive materials (Earl's / Peavy's towel trick for example) *can* be used for diffraction alignment as well".
This keeps technical aspects and mechanisms clearly separated.
Michael
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Hi Everyone,
It's quite simple really.
By definition:
1. A waveguide is a transmission line feeder.
2. A horn is a radiator.
Think of it this way - the megaphone exhaust system on a racing motorcycle is part waveguide and part horn. The exhaust pipe is the waveguide, and the megaphone on the end is the horn.
Dr Geddes' "oblate spheroidal waveguide" acts primarily as a horn, not a waveguide.
Don't let anyone convince you otherwise...
Kind regards,
David
It's quite simple really
.By definition:
1. A waveguide is a transmission line feeder.
2. A horn is a radiator.
Think of it this way - the megaphone exhaust system on a racing motorcycle is part waveguide and part horn. The exhaust pipe is the waveguide, and the megaphone on the end is the horn.
Dr Geddes' "oblate spheroidal waveguide" acts primarily as a horn, not a waveguide.
Don't let anyone convince you otherwise...
Kind regards,
David
"waveguide" is homonym
1. a transmission line feeder
2. oblate spheroidal (and similar) horn
Allow me to add:
"wave guide" just sounds cooler than "horn" - I mean - every cowboy knows about horns - BUT - if you tell him about "waveguide" - WOW !!!
Michael
I love this point of view - brings testosterone level into play - long overdue !
Hi Everyone,
It's quite simple really
...
Think of it this way - the megaphone exhaust system on a racing motorcycle is part waveguide and part horn.
I was thinking something like "acoustical impedance transforming device with aspects of directivity control".
Rolls off the tongue.
Extra credit question: what's unique about the horn in the attached picture?
David S.
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