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Re: How would you clean up this file?

Subject: Re: How would you clean up this file?
From: "Ed Anson" ed_anson
Date: Sat Jun 24, 2006 9:20 am (PDT)
Dana,

Welcome to the wonderful hobby of nature recording. For some, it's a 
wonderful career.

For general information on production and post production of audio, I 
strongly recommend reading Jay Rose's books. Although they are 
ostensibly about audio for digital video, the principles of audio are 
entirely the same.

On Jun 24, 2006, at 10:23 AM, Dana Blackmer wrote:

> The link at the end of this message is to a 68 second mp3 file of a
> dawn chorus I recorded last Sunday in Jefferson National Forest in
> southwest Virginia.  I am new at nature recording, and wanted some
> suggestions as to how to reduce the low end rumble, hiss, and if
> possible, some of the insect noises.
>
> The attached clip has most of the challenges I'd like to address:

I didn't hear the rumble and hiss. If they were there, they were masked 
by a different problem. I heard a sound that I usually associate with 
over use of a noise reduction filter. Since you say this clip is not 
filtered, then the artifacts are most likely due to the mp3 encoding.

>
> 1 - Thoughout the recording there is low frequency buzzing from
> insects.  Can this sound be filtered out or diminished without
> getting the "blurby" sounds I sometimes get with a filter?  Can this
> noise be reduced without decreasing the quality of the other low
> frequency sounds?

The insect sounds are quite broad band. That means they would be 
extremely difficult to remove or substantially reduce without causing 
great harm to the rest of the sound. Besides, insects are a natural 
part of the soundscape. An occasional insect fly-by gives depth and 
character to a nature recording IMHO.

>
> 2 - There is some high frequency hiss in the recording.  How would
> you reduce this without substantially changing some of the high
> frequency sounds, like the bird call from 1:05 to 1:08?

Hiss can be problematic because it is very broad band. It is best 
removed by recording without it. Since you have good equipment, if you 
learn a bit more about recording technique you can record less noise 
next time. Rose's books go into substantial detail on that, and you can 
also learn a lot by reading the archives of this list.

>
> 3 - At 1.5 seconds and again around 18 seconds an insect flies by -
> is there a way to decrease or eliminate this without substantially
> changing other low frequency sounds, like the "gunk, gunk" calls of
> the green frogs in the background?

No.

>
> Generally, I am looking for some guidelines as to how to approach
> the task of post-production - what filters, noise-reduction methods,
> EQ, etc. to use, in what order, and how to do this without making
> the result sound too sterile.  Any advise would be greatly
> appreciated.

Removing natural sounds makes a recording more sterile IMHO. The sounds 
that were not present in the natural setting are best removed by not 
recording them. Selective removal of sounds generally happens only in 
fantasy movies. In the real world, a considerable amount of knowledge 
and skill are required to get good, clean recordings. That comes with 
study and practice. Keep trying. You can do it.

BTW: While I was writing this, Derek's response came through. It seems 
he's saying much the same thing as I am but in different words.

>
> FYI, I used an HBB Portadisc and MKH 30/40 to get the recording and
> will be using Adobe Audtion 1.5 to do any post stuff.  The only
> thing I did to the attached file was to mix the MS to XY using
> Audition's channel mixer at the default settings and saved the file
> as an mp3 to save some space.
>
> Thanks in advance to anyone who can give me some suggestions.  My
> hope is that the more experienced of you can educating the less
> experienced of us in the science and art of what to do after you've
> finished recording.
>
> Dana
>
> http://www.danablackmer.com/AudioFiles/DawnChorus.mp3
>

Ed





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