Marco, Gianni, Bruce and other Gentlemen.
Since Telinga started in 1981, there have been some holy cows to be killed.
The first we met was a dogm that =94the input impedance of a microphone
amplifier must be the same as the output impedence of the microphone=94.
Lots of people spend lots of time and money on something they called
=94impedance matching.=94 The dogm lived on until the end of -90. The topic=
shouldn=B4t have got any attension at all, really, but a manufacturer
which used a special input transformer put a lot of stress on the
importance of it.
Another =94expert opinion=94 was that =94you can=B4t record owls with a
parabola,=94 which meant that parabolas were totally worthless in all
ways. At Telinga we still get mails occationally about this and Bruce,
here, just recently had to point out that =94There is no reason why you
wouldn't be able to record frequencies of 20Hz, it just won't have
gain.=94 Thanks for that.
Now it seems like a new holy cow is to be born: The Tragedy Of the Bass
Dip and the Holy Healing Plate.
Yes, when a signal hits an omni in focus of a parabol, gets reflected by
the parabol and then back to the omni a bit later, there will be a dip
in the frequency curve. It=B4s true. It=B4s been known for some 100 years
and hundreds++ of serious DIY people have tried all logic ways to give
a lift to the peak, including the plate that is now on the agenda.
But seriously: How many birds have you lost because of a 6db dip at some
600 Hz? None, I=B4m sure. The people recording low-freq. mammals will do
best with HQ shotguns anyway.
Even regarding it=B4s low importance, it is a difficult problems to solve.=
A number of measurements done at Telinga over the years, show that a
plate flattens out the dip a bit, but that new dips and peaks occur at
other frequencies in a more or less random way. (Diagrams can be posted
on request.)
The by far best way to get nice mono sound out of a parabol is to use a
suitable cardioid, facing inwards into the dish. Heres is a nice
reference to this subject :
http://daanhendriks.co.uk/wildlife-nature-sound-recording/telinga-tastic-su=
per-close-up-recordings-of-birds-crickets/
The Telinga Twin-Science mic have both types integrated =96 a fine tuned
cardioid facing inwards to the dish and an omni facing out, for windy
conditions and for better handling noise. Then one can select the best
recording by listening in post production.
Klas-G=F6ran Strandberg, Telinga Microphones, 2017-10-11
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