Posted by: "John Hartog"
>
>> I'm wondering if the "no noticeable decrease in gain with a barrier"
>> effect is particular to less-rigid dish materials. Because the dish
>> warps under its own weight a bit the focus also becomes somewhat
>> warped or stretched, thus the gain at any specific point is already
>> compromised. A barrier might make up for this a bit by obstructing
>> the diffusion or by offering a pressure zone.
Certainly the plastic Telinga dish is only a approximate shape, less
because of gravity and more because of how we store and transport it. At
least that's my experience with the Telinga in field use. Probably
people make a bigger difference in how they adjust focus, however.
Generally parabolics are best thought of as producing a small 3d volume of
high gain sound at their focus rather than a point of best focus. This
pretty well covers any small irregularities in the shape of the parabola.
Note also that any warp due to weight (which I have seen in larger
parabolics) will the symmetric in the same way the two stereo mics are.
>> Based on this conjecture, would you say I'm on - A:) good caffeine,
>> or B:( Bad caffeine?
No caffeine?
Walt
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