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RE: noise reduction-parametric eq-a basic example

Subject: RE: noise reduction-parametric eq-a basic example
From: Fernando Gonz=E1lez Garc=EDa <>
Date: Tue, 30 Nov 2004 13:55:55 -0600

-----Mensaje original-----
De: Martyn Stewart 
Enviado el: Lunes, 29 de Noviembre de 2004 06:57 p.m.
Para: 
Asunto: RE: [Nature Recordists] noise reduction-parametric eq-a basic
example



Nice simple example John....

Martyn

Martyn Stewart
Bird and Animal Sounds Digitally Recorded at:
http://www.naturesound.org
N47.65543   W121.98428
Redmond. Washington. USA
Make every Garden a wildlife Habitat!

425-898-0462


-----Original Message-----
From: John Hartog 
Sent: Monday, November 29, 2004 1:39 PM
To: 
Subject: [Nature Recordists] noise reduction-parametric eq-a basic example



The program I have been using, Cubasis VST, doesn't have any
fancy noise filters, but it does have a parametric equalizer.   I
have found this equalizer to be pretty good at reducing unwanted
noise.  In case someone out there doesn't know to use a
parametric equalizer, here is a basic example of how I use it.

The other day I went out to a local, urban wildlife area to test how
well two Shure183s sound as steroe in a parabolic dish - I
recorded some chickadees and some other small birds, maybe
bushtits, in a small oak tree.
<http://groups.yahoo.com/group/naturerecordists/files/041121a.mp3


As you can hear, there is a lot noise from the surrounding roads
-  low rumbling and howling.
The parametric equalizer I use has two sets of three adjusting
knobs:  Gain, Frequency, and Q.=20
With the gain knob you can cut or boost; with the frequency knob
you can center on a particular frequency; and with the Q knob you
can adjust the bandwidth affected.

The first step is isolating the frequency of the noise. To do this, I
set the Q for the narrowest bandwidth, boosted the gain up, and
swept through the frequencies until the noise comes through
loudest.  In the recording, the rumble is loudest at about 72Hz.=20
Next cut the gain and abracadabra the rumble disappears.=20
<http://groups.yahoo.com/group/naturerecordists/files/041121b.
mp3>

Now the rumble is better but the howling is still there.   The
equalizer in the program I am using allows two sets of
adjustments for each pass.  So, on the second set of knobs I go
through the steps again:  boost the gain, isolate the frequency,
cut the gain.  The howling seemed to be centered at  around
254Hz.=20
<http://groups.yahoo.com/group/naturerecordists/files/041121c.
mp3>

Well, is that any better?  Do the birds still sound good?
This just a rough example, thrown together pretty quickly.  It
usually takes more messing around to get it right, and if I tried it
again I'm sure I would do it a bit differently.
-John Hartog







"Microphones are not ears,
Loudspeakers are not birds,
A listening room is not nature."
Klas Strandberg
Yahoo! Groups Links











"Microphones are not ears,
Loudspeakers are not birds,
A listening room is not nature."
Klas Strandberg
Yahoo! Groups Links











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