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Re: Minidisc Recording Problem

Subject: Re: Minidisc Recording Problem
From: Walter Knapp <>
Date: Tue, 09 Jul 2002 17:32:09 -0400
Stuart Fairbairn wrote:
> 
> Walter.I use Cool Edit 2000 to edit and reduce unwanted sounds. If I use
> Sound Reduction I get a mass of artifacts, warbles etc. I therefore use the
> FFT filter to remove the frequencies below the call and on occasions a
> different setting to remove sounds above. From your comments it seems
> possible to use the noise reduction after using the filter without
> generating the unwanted warbles etc? Is that how you use it?

As Doug noticed, you are probably applying the noise filter way too
strongly, generalized noise filters really fall apart if applied
strongly. I rarely apply it more than about 6 dB. That's a general rule
about filters, apply them sparingly. The other trick can be to apply
them several times weakly rather than one time strongly. Often the
results are better that way, although there is a lot of trial and error 
involved.

My mac software allows me to set up an array of filters that will be
applied at once and I can set them up while playing the track to listen
to the result while adjusting. It also has sonogram facilities and that
can be put in any part of the filter bank to check what's going on. I
use the cutfilter, or even a couple cutfilters top and bottom to slice
out the band of interest, Then if I need to do any sharp drops I'll put
a notch filter next, then run that through the noise filter. This is one
of the adaptive type noise filters where you grab a sample of the noise
you don't want, and it works only on that, it's not a generalized noise
filter. So, I can apply it pretty strongly without artifacts, but don't
usually have to. I have the sonogram set on the output end, and any
filter component can be bypassed to see what each one is doing. As well
as listening, of course. When it's all set and sounds the way I want and
looks good on the sonogram display I save the file and it does the full
processing and saves it to a new copy. I can save the filter bank setup,
and have different ones saved for different species of frogs, that way I
only have to tweak them and give the noise filter a new sample, which is
a little quicker than setting up from scratch. The filter bank is one of
the ways I can really bring my G4 to it's knees, though my Son's dual
1ghz G4 seems to be capable of handling anything we have thrown at it so far.

The mac software I use for this is Spark XL, where it's called the FX
Machine. I believe FX Machine is available for Windows if you have a
suitable host application. The latest version of Peak (for OS X) has a
crude version of this sort of filter setup. That's their Vbox, which
works with VST filters.

If you can't stack filters like this, you can run them individually one
at a time. They do interact some, so it will take a lot more fiddling.
And be sure and have a unfiltered copy to fall back to.

Note that this sort of heavy handed filtering does loose all or nearly
all of the ambiance. You kind of just get the call. Still, it can be
kind of magical to hit the bypass and listen to the raw, then click it
in and the jet planes, trucks, housebuilding, and most of the wind noise
in the trees goes away and there's the call, nice and clear. At least
that's the sort of thing I could do to a recent mockingbird recording.
And a recent frog recording I could nearly remove the 6 other species of
frogs, and all the insects and keep the one species I wanted. My science
recording of the last several years this was more or less a no-no, but
I'm having some fun with the toys now. I've only had this system for a
couple years.

As far as order to apply filters, I've experimented a number of ways.
There are slight differences and the best order varies. It does, in
general seem to sound a little better putting the noise filter after the
cutfilters. 

Walt



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>From   Tue Mar  8 18:22:31 2005
Message: 1
Date: Tue, 09 Jul 2002 14:24:19 -0700
From: KACastelein and DJLauten <>
Subject: Samplitude vs Cool Edit

John, folks,

I have both Samplitude and Cool Edit, although by no means am I an 
expert at either.  I used Samplitude for a while, but recently began to 
switch to Cool Edit.  The two programs (and by the way I am not talking 
about the PRO versions) seem very similar.  The main reason I switched - 
I have nothing but good things to say about Samplitude, it worked great 
for me doing the basics - is because I could not find any feature on 
Samplitude that would permit me to display the birdsongs as Sonograms 
(or whatever you wish to call them).  Maybe Aaron knows something I 
don't about Samplitude.  One other thing is I found the folks at SEK'D 
that make Samplitude to be extremely friendly and nice.  I have one of 
their soundcards (PRODIF PLUS) which is no cheap soundcard.  After about 
a year and a switch of computers, it died on me.  They quickly replaced 
it at no cost to me.

Cheers
Dave Lauten
Bandon OR





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