Posted by: "Steve Pelikan"
>
> There's also an issue with the complex "comb filtering" created by
> reflections inside the dish which seems to be less with cardioids than
> omnis. If the focus/microphone is inside the edge of the paraboloid,
> much of the (higher Hz) lateral noise is excluded by the dish itself,
> even using an omni.
Actually it's not inside the dish, it's a standing wave created in front
of the dish by the interactions of the reflections and the incoming
sound. This occurs at a low enough frequency that it's often mistaken
for a frequency cutoff of parabolas (which really does not exist). Ideal
would be a focus that's 1/4 of the dish depth, a arrangement that's not
generally considered all that practical (and would probably require a
omni). Definitely you want your focus point inside the dish to avoid the
standing wave as much as possible.
> I now know several people who swear that expensive cardioids are better
> in parabolas than (affordable) omnis, and others who make fantastic
> (envy producing) recordings with affordable/mid-priced omnis.
If you believe in what you are using you probably do a better job of
technique. The key is as much technique as design.
Note the Telinga Stereo mic is a multicapsule boundary mic design.
Different from either a cardioid or omni...
> The problems with wind are significantly reduced with omnis and that
> would decide the question for me.
Parabolas in and of themselves reduce wind problems.
Walt
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