naturerecordists
[Top] [All Lists]

Re: What causes recording rumble?

Subject: Re: What causes recording rumble?
From: madl74
Date: Tue Jun 30, 2015 6:25 am ((PDT))
> I was using batteries, but after doing additional recordings its clear th=
at the one I posted was getting interference. Here=92s a screenshot from a =
better recording: https://www.dropbox.com/s/k76hl2tuvjp3yzy/Rumble2.jpg

Charles,

Looks good to me. If you take different samples you should get different
wiggles, but the noise level is generally constant with frequency.

More theory coming up. :-(

Noise figures are usually given with a frequency weighting such as "A
weighting" which at least is consistent, but which does not represent what=

the ear hears at noise levels. The A curve uses a steep bass cut and also
falls off after 1KHz which is fine with studio recording but which simply
does not represent what the ears hear with quiet sounds as in nature
recording.

The Wiki page
https://en.wikipedia.org/wiki/A-weighting
is reasonably accurate and gives other curves but they are based on 40 phon=
s
when we are recording as low as 20phons. See the para on "Deficiencies of
A-weighting".

The original Fletcher-Munson_curves of the ear's responses are on;
https://en.wikipedia.org/wiki/Fletcher%E2%80%93Munson_curves

David Brinicombe











"While a picture is worth a thousand words, a
sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause.



------------------------------------------------------------------------
Yahoo Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/naturerecordists/

<*> Your email settings:
    Digest Email  | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/naturerecordists/join
    (Yahoo! ID required)

<*> To change settings via email:
    
    

<*> To unsubscribe from this group, send an email to:
    

<*> Your use of Yahoo Groups is subject to:
    https://info.yahoo.com/legal/us/yahoo/utos/terms/

------------------------------------------------------------------------


<Prev in Thread] Current Thread [Next in Thread>
  • Re: What causes recording rumble?, brini <=
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