naturerecordists
[Top] [All Lists]

RE: Minidisk data transfer and bat recordings

Subject: RE: Minidisk data transfer and bat recordings
From: "?" <>
Date: Sun, 25 Jan 2004 19:30:35 +0100 (MET)
> Was there any filtering done on your recordings? They certainly sound
> crystal clear!

Martin,

Yes, I have applied a simple and relatively steep 750 Hz high-pass filter
(or 7.5 kHz expressed in the original ultrasonic domain) in order to remove=
 any
potential low-frequency noise. Other bat detector brands are already
equipped with an integrated and fixed analog high-pass filter. Generally, a=
ny
signals below about 10 kHz are usually out of interest to bat researchers.=


In my recordings, the signal components above the 7.5 kHz high-pass cutoff
frequency have not been further filtered (no FFT noise gate or something
similar has been applied).=20

The main reason for the crystal clear sound is the increased bit-depth of
the AD converter. Unlike other time-expansion detectors that have only 8 bi=
ts,
the UltraSoundGate devices provides a 16 bit dynamic range.

Regards,
Raimund

--
+++ GMX - die erste Adresse f=FCr Mail, Message, More +++
Bis 31.1.: TopMail + Digicam f=FCr nur 29 EUR http://www.gmx.net/topmail



________________________________________________________________________
________________________________________________________________________

<Prev in Thread] Current Thread [Next in Thread>
Admin

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU