Lang Elliott wrote:
> Actually, I've never tried pointing the SASS directly into the dish, but =
it
> is obvious that neither mike in the SASS would be at the focal point of t=
he
> parabola, so I don't see the point.
I have considered trying a SASS on the 30" dish I have. I'm certain the
SASS is simply too wide for the Telinga. It would probably work better
on a longer focus parabolic like the old white homemade one I have. The
30" is also a more relaxed curve.
Three other thoughts I've had in case someone is interested.
First, Put a SASS (or really any stereo setup) facing a parabolic curved
surface, curved only one way so as to be a horizontal parabolic channel.
My feeling is this would not provide the gain of a regular parabolic,
but might make more reach for mics like the SASS.
Second, redesign the SASS concept. Make the head shape more triangular
pointing to the center of a regular parabolic dish. And make the
boundary layer perpendicular or so to a line from the center of the
parabolic. This should cut off a lot of the wide field of the SASS,
making more of it's signal be from the reflector.
Another, even more exotic variant of a SASS might be based on crown's
experimental dish PZM. This dish has the mic mounted at the dish
surface, not at the focus, and is aimed out one edge. Two of them, SASS
like would look kind of like a pair of Mickey mouse ears. Except much
bigger. Or maybe just one dish, with mics at each edge. The whole area
of curved surface boundary mics has not been worked much.
> By facing the mikes and barrier outward, the stereo soundfield is the sam=
e
> as that obtained by using the mikes and barrier outside of the parabola,
> just like Klas suggests for using the Telinga Stereo mike without parabol=
a
> for gathering soundscapes.
>
> However, I don't use my stereo parabolic mike + barrier for soundscapes
> because it doesn't sound near as good as the SASS. I only use that setup =
in
> the parabola, when I really do want loud closeups of individual species.
>
> Lang
>
> What about having the barrier between the mics, but not extending down
> into the dish between the mics. Thus sound reflected from both sides of
> the dish would reach each mic but there would remain a separation
> between the two preventing direct crossover. For example Lang, what
> would you get if you pointed your SASS setup into the dish?
> Kevin
We are really getting into two types of barrier and need to keep it
straight. A central hard barrier like in the original Telinga reflects,
just like the surface of the parabolic. But a barrier like is in the
SASS or a Jecklin disk absorbs sound. The effects are quite different.
The SASS also has two active boundary mics and a view about 3/4 of a
circle. It's quite a ways from just two mics out bare. In front of a
parabolic facing it the SASS barrier would be extending into the dish
between the mics.
Walt
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