Dan Dugan wrote:
> I don't like the look of the tube and the end cap area where the mike
> has to be. There is so much obstruction. You want the mike to sit in
> a spot where, pointing back toward the reflector, it can see the
> whole surface of the reflector without obstruction. I see no reason
> for having such a heavy structure there. Imagine something like a
> lampshade harp.
Imagine such a thing hitting brush. Or snagging in it. I've been there
and done that. That is why the structure was not lightened much more. I
expect the mic end to be able to bump something without losing
alignment, or worse, breaking.
The mic will see the entire parabolic on a sonic level. I've tried both
styles over the years and both work the same. This is just a lampshade
harp that's closer to the mic and 4 legged. This is a less expensive
method while still providing necessary mic protection and the theme is
inexpensive homemade parabolics that are relatively easy to construct.
Also think about Omni's being used in parabolics pointing away from the
dish. That works, even though the Omni pickup has no direct view at all,
the body of the mic is in the way.
You are dealing with a pressure variation, it's not light and not a
water wave. The focus is actually a small volume in which the pressure
variations from sound are pretty even. You have to do a fair amount to
mess it up. At least for the kind of frequency response of a inexpensive
tie tac mic.
Were we using a heavier duty reflector, and willing to drill holes in it
then a bridge design is common. I used one of those for years. And the
bridge structure on that was 3/4" wide and in the field of view blocking
part of the reflector in two directions. It worked fine. (it also
snagged brush, and had exposed mic wiring which cost me a couple mics)
Since I was avoiding drilling holes in a 1mm thick Telinga reflector all
support will have to come off the center.
I've got the mic that it's designed to fit, and a working MZ-R30. So
I'll see what I can pick up in the next few days. Then we will know for
sure. My worry is more I might have cut it a slight bit too short for
accurate focus, I estimated off the Telinga setup, and the mic there is
in a large chunk of foam so I'm not positive of it's exact location.
Walt
________________________________________________________________________
________________________________________________________________________
|