Raimund Specht wrote:
> --- In Walter Knapp <> wrote:
>
>> I wonder what it's frequency response would be combined with a
>>parabola. The jaggies also have a look of some of the things
>
> sennheiser
>
>>dealt with making the MKH-800. All those reflections off tiny
>
> surfaces.
>
> As we have seen recently, a parabolic dish should work satisfying at
> higher frequencies, especially in the ultrasonic domain (where the
> dish could be smaller). Reflections and resonance within the
> microphone capsule are responsible for the distortions of the
> frequency response at the upper edge.
>
> A problem in recording fast-flying bats could be the strong
> directionality of a parabolic microphone. Several bat species (those
> feeding close to vegetation) have zigzag-shaped flight paths, where
> it would be extremely difficult to track a single bat (especially at
> total darkness). But it might be possible for species flying more
> straight ahead at higher altitudes at dusk.
I'm fairly familiar with some of the bats here as far as flight path.
Our most common ones at the house are the highly zigzag type, but they
also do habitual paths every night. I think they could be tracked.
Especially if the dish is small and light. You could also follow them at
greater distance, where tracking would be easier.
> I still have not tried my new Telinga Universal for bats because
> they are still sleeping here. However, they should appear within the
> next few days.
>
> There should be no problems in recording stationary grasshoppers. I
> know that several researchers have used parabolic reflectors
> successfully for locating and recording bush crickets and cicadas:
> http://www2.arnes.si/~ljprirodm3/cikade.html
I've used the Telinga with DAT Stereo to listen in on insects too,
though only in regular audio ranges. Easy to zero in on with the stereo.
The little grass frog, smallest NA frog has calls most would think were
insects:
http://wwknapp.home.mindspring.com/docs/little.grass.frog.html
So, I have to be able to make the distinction if it's a frog or insect.
This one I can easily pick out while driving down the highway at
30-40mph. Once I learned it's call.
The bats are out here. I watched one for a little while with my
nightscope recently. That's even more tricky for tracking than a
parabolic would be.
Walt
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