The magic word I used was 'superimposed'. The SHM is superimposed on the random motion of the air molecules.
I can't picture it and no model I've seen simulates it.
That's a good way of dealing with it.
Better to stick to the simple models which do not overtax our imaginations! 😎
Better to stick to the simple models which do not overtax our imaginations! 😎
I'm a little surprised someone who knows what's actually happening hasn't come to the rescue before now.
More interesting stuff here:
Andy Unruh - Understanding Cabinet Edge Diffraction
But keep in mind that near the end he states:
He points the interested reader to a Vanderkooy paper on diffraction. I just happened to read "An analytic secondary source model of edge diffraction impulse responses" by Svensson Frank and Vanderkooy, 1997 and now my head hurts. This stuff gets steep pretty fast.
It seems that there is a good understanding from a somewhat phenomenological point of view of cabinet/baffle edge diffraction but that a more fundamental description of the problem via physics is nearly intractable. The idea that the impedance change at the edge causes a new "phantom" source to be located there is evidently well accepted, but the details of what exactly happens is just not so easy to describe mathematically.
Andy Unruh - Understanding Cabinet Edge Diffraction
But keep in mind that near the end he states:
He points the interested reader to a Vanderkooy paper on diffraction. I just happened to read "An analytic secondary source model of edge diffraction impulse responses" by Svensson Frank and Vanderkooy, 1997 and now my head hurts. This stuff gets steep pretty fast.
It seems that there is a good understanding from a somewhat phenomenological point of view of cabinet/baffle edge diffraction but that a more fundamental description of the problem via physics is nearly intractable. The idea that the impedance change at the edge causes a new "phantom" source to be located there is evidently well accepted, but the details of what exactly happens is just not so easy to describe mathematically.
No need to bet, Matt, I know they wouldn't say that!
As each new phenomenon is discovered, physicists quickly refine the model to reflect the new 'reality'. Think of the progression of the model of the atom.
That's how physics works, it has always been thus!
You must be (sharp intake of breath) a biologist! 😀
I think that just about sums it up, Charlie, but thanks for all the Christmas holiday reading material.
I'll make a physicist out of myself yet! 😱
Plato got virtually everything wrong! Plato got virtually everything wrong | Prospect Magazine
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Wouldn't that be a mathematical model and how can it describe something we still don't know?
Impedance has a frequency dependant component. I think the impedance model is probably explaining the same/similar observed phenomena in a different way. As usual in science a model is used to describe an observation and which model is best depends what exactly is being focused on. There seems hardly ever to be a one-size-fits-all answer and usually it doesn't matter much, this is probably another such case, ie, I wonder how useful a deeper understanding would be when it comes to our hobby?
Yeah, imagining just for fun. Baffles step and diffraction are measurable phenomenon and as such pretty well known here in the forums, along with the cure which is rounding and smoothing all sharp stuff. Deep understanding could yield some a-ha moments though, which could lead to better speaker built as well as provide for some marketing jargon if one wants to take it commercial 🙂 Have fun ya all!