I think that maybe you are forgetting that a waveguide requires a +6 dB / oct slope, which when done passively results in the HP filter attenuation at 10 kHz to be 0 dB in my systems. There is no room for more attenuation from the foam.
*if* dampening materials would not add a sonic pattern of its own - people would stuff their closed boxes like hell and than correct via EQ.
Ever thought about why this is rarely reported to provide "the best ever sound" ?
Hence I made my point whereas Earl only focused on "not any SPL to waste"...
Michael
Ever thought about why this is rarely reported to provide "the best ever sound" ?
Hence I made my point whereas Earl only focused on "not any SPL to waste"...
Michael
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Yeah, I found it pretty similar to you in working with my OSWG, once I knocked the "CD lump" down, there was little wiggle room left- I still stuck an extra 1R or so in for attenuation, but it's funny to work with a horn system in which the horn doesn't, or needs very little, padding.
Hello Earl,
I think there is no need for the moment for me to separate what is due to diffraction near the throat from what is due to HOMs.
If one day I'll plan to do such I'll probably use an approach as done by Makarski in his work "tools for the professional development of horn loudspeakers" (see page 124 of the document of my conference about horns).
IMHO, your dismiss of the wavelets methods desserves you.
Best regards from Paris, France
Jean-Michel Le Cléac'h
I think there is no need for the moment for me to separate what is due to diffraction near the throat from what is due to HOMs.
If one day I'll plan to do such I'll probably use an approach as done by Makarski in his work "tools for the professional development of horn loudspeakers" (see page 124 of the document of my conference about horns).
IMHO, your dismiss of the wavelets methods desserves you.
Best regards from Paris, France
Jean-Michel Le Cléac'h
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Bjorn, this is 321 pages of dense math
couldn't you give us a brief summary ?
OK, here's a very brief summary: Higher order modes do exist, and Williams shows you some of the things you can do with them, and how to do it.
Earl, can it be said that higher order modes is the spatial equivalent of harmonics in the frequency domain? That in the same way as a non-sinusoidal periodic signal can be decomposed into a fundamental frequency and harmonics, a spatial wave that is not spherical/cylindrical/plane can be decomposed into a fundametal spherical/cylindrical/plane wave and higher order modes?
Regards,
Bjørn
You're not actually answering the question
.Btw, stuffing boxes to the brim is exactly what I do.
You're not actually answering the question
Btw, stuffing boxes to the brim is exactly what I do.
Great you have succeeded where other failed - any secrets in your way to do it ?
At least thats what Jean-Michel is looking at it AFAIK
to state that they exist is a "great word" - maybe better put to say those effects are a conceptual summery to diffraction effects with respect to its source origin in order to get a math handle on the subject.
Mostly - as far as I can see - its interesting only for tracing back source origin to render 3-D holomaps for military use and seismic apps.
OK, here's a very brief summary: Higher order modes do exist, and Williams shows you some of the things you can do with them, and how to do it.
Veeery brief indeed !
Michael
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OK, here's a very brief summary: Higher order modes do exist, and Williams shows you some of the things you can do with them, and how to do it.
Earl, can it be said that higher order modes is the spatial equivalent of harmonics in the frequency domain? That in the same way as a non-sinusoidal periodic signal can be decomposed into a fundamental frequency and harmonics, a spatial wave that is not spherical/cylindrical/plane can be decomposed into a fundametal spherical/cylindrical/plane wave and higher order modes?
Regards,
Bjørn
Yes its all "modal" decomposition.
It might be better to think of a drum head or membrane and how it vibrates. We all know that it has modes and how I hit it determines how the modes are excited. But any vibration, no matter how complex, can be analyzed down to a sum of the "allowed modes" for the shape under consideration. If the membrane is square then the modal summation is a Fourier series in two directions. If the membrane is infinite in extent then the series becomes a 2-D Fourier Transform just like the example that you used for harmonics.
In the case of an OS waveguide the modes are know (but they are not simple sines and cosines as in the Fourier case) and any waveshape can be analyzed as a sum of these modes.
However, if the waveguides shape is not OS, or one of the seperable shapes, then the modes are coupled together and cannot be seperated. They still exist, but one cannot seperate a 3D waveshape as a simple sum over the modes. One can always decompose the wave at any plane, such as at the mouth, and find a 2D series representation, but unless the modes are known one cannot propagate this wavefront back down the body of the device to find out what the waveshape was at the throat, or given the throat wave, what it will be at the mouth. This is a key aspect of the problem.
I am disappointed by your arrogant and sarcastic attitude - an attitude I can't remember to have seen from you before. The way I see it, a forum serves to increase collective knowledge and I was hoping that I might learn something from you in this thread. Too bad, I seem to have misjudged you.
You are right my tone wasn't "the best one" - my apologies.
Besides that, I *may* come up with some ideas to the topic - but its not the place here for "in depth discussion" about sonics of dampening materials as Earl does not seem to see this of any relevance for him.
Strange enough, as dampening - and especially dampening of CMP effects (echo and looped echo) are playing a monumental role in audio.
Only few audio designs usually do not use any - "traditional" horn / waveguide / diffraction alignment device designs being one of them. One cold think that the dedicated horn sound lovers possibly share my outspoken aversion to dampening materials - without even knowing.
Earl, having "invented" or at least prominently popularized stuffing of horns (and thus IMO diluted "pure horn feeling") actually should have known that there is a sound wise trade off - but he seems not to be willing to enter this discussion.
Michael
PS
my question about what you did any different was not *only* arrogant...
Besides that, I *may* come up with some ideas to the topic - but its not the place here for "in depth discussion" about sonics of dampening materials as Earl does not seem to see this of any relevance for him.
Strange enough, as dampening - and especially dampening of CMP effects (echo and looped echo) are playing a monumental role in audio.
Only few audio designs usually do not use any - "traditional" horn / waveguide / diffraction alignment device designs being one of them. One cold think that the dedicated horn sound lovers possibly share my outspoken aversion to dampening materials - without even knowing.
Earl, having "invented" or at least prominently popularized stuffing of horns (and thus IMO diluted "pure horn feeling"
) actually should have known that there is a sound wise trade off - but he seems not to be willing to enter this discussion. Michael
PS
my question about what you did any different was not *only* arrogant...
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Could somebody point me to a curve comparison of a horn with and without the internal damping foam? I think I've seen it somewhere in the past (maybe here a couple hundred pages back )
I would think a good set of curves would settle the argument, at least for those that value measurements.
David
) I would think a good set of curves would settle the argument, at least for those that value measurements.
David
Could somebody point me to a curve comparison of a horn with and without the internal damping foam? I think I've seen it somewhere in the past (maybe here a couple hundred pages back
I would think a good set of curves would settle the argument, at least for those that value measurements.
David
Hi Dave
I have that data, but I don't think that it would settle anything. What is the "argument" that you think that it would settle?
Hi Earl,
I thought you were saying that internal damping improve response (smoothed resonances due to mouth reflections) while others were saying "yes but" not liking some supposed detrimental effect of damping material. Wasn't that "the argument"?
Actually, I just wanted to see the extent of the performance improvement. Nothing more, nothing less.
David
I thought you were saying that internal damping improve response (smoothed resonances due to mouth reflections) while others were saying "yes but" not liking some supposed detrimental effect of damping material. Wasn't that "the argument"?
Actually, I just wanted to see the extent of the performance improvement. Nothing more, nothing less.
David