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Re: Bat detector calibration

Subject: Re: Bat detector calibration
From: "Peter Shute" pshute2
Date: Tue Mar 22, 2016 1:46 pm ((PDT))
Raimund wrote:

> I would first try common earphones or headphones. It is unlikely that the=
> also have a dip at exactly 30.0 kHz. I think this is what Peter already w=
anted to
> do.
> I see no big advantage in using a piezo transducer for this purpose. Thei=
> frequency response is also far from perfect - there are usually numerous =
> and peaks as well...

I've now managed to generate working wav files at 15-45kHz in 5kHz incremen=
ts, and the detector could detect them all clearly when played on the M10. =
It's a pity the recorder doesn't support higher bit rates, it would make a =
nice portable calibrator. Thanks for that idea, Raimund.

For what it's worth, I ended up using sox to generate the files, with this =
command (with the help of the sox users mailing list):
sox -r 96000 -n -c 2 -b 24 stereo30k.wav synth 60 sine 30000

I should now work out what I did wrong in Audacity to end up with a file th=
at wouldn't make the detector respond, and continue trying to get higher fr=
equencies playing on a PC. I assume that all of my previous tests may have =
been sabotaged by something I did wrong in Audacity.

Peter Shute

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