naturerecordists
[Top] [All Lists]

Re: New thread: Low Hz filtering

Subject: Re: New thread: Low Hz filtering
From: "David Michael" wildlifeanalysis
Date: Mon Apr 6, 2009 5:58 am ((PDT))
Hi Steve

I also like to record soundscapes. From a scientific perspective, it is int=
eresting to leave in all the frequencies that you can pick up with your equ=
ipment, but "microphones are not ears" as they say.

If the recording is intended for general entertainment, and not science, th=
en I find that filtering out the lowest part of the spectrum makes for a ni=
cer listening experience. My personal rule of thumb when running this highp=
ass filter is to not chop out the biology. So a filter that removes everyth=
ing below 200Hz will cut out alot of traffic and airplane sounds but may no=
t be appropriate for a Bullfrog chorus.

Best
David

--- In  "Steve Pelikan" <> wrot=
e:
>
> Friends:
>
> This is a subject that has been touched on often but never discussed expl=
icitly (in my memory) and that is low frequency filtering of "ambient" reco=
rdings.
>
> I've started to get interested in making stereo recordings of entire "sou=
nd scapes" --- meaning whatever is there --- and am in the process of decid=
ing how I'll treat such recordings --- so I'd appreciate other people's opi=
nions.
>
> My understanding of the 'elevated' low Hz 'noise' in most settings is tha=
t most of it (that I experience) is low Hz man made noise that carries a lo=
ng way because of its wave length ( Hi Hz interacts with "stuff" and disapp=
ears rather quickly with distance).
>
> When I'm out to document things I record w/o filters. This is in the east=
ern US where there's lots of manmade sound. When I want something that "sou=
nds nice" I use (or process with) a low Hz filter (10 dB to 20 db/ octave s=
tarting at 160 -600 Hz, say).
>
> I've heard "professional" recording with _nothing_ below 200 Hz
>  and they sound goofy to me. I've been tempted to filter recordings more =
heavily but realized that it (for eg)  might eliminate low Hz thumps of a w=
oodpecker on a rotten stump.
>
> How do you al think about this issue? What do you do?
>
> Sometimes I put on a low Hz filter so I can set the overall record level =
higher (buy headroom by eliminating something under 100 Hz). Sometimes I re=
ally miss the low Hz stuff.
>
> Sorry for this elementary and  ambiguous posting/question but it think th=
ere is room for some discussion on this topic. In the end we all need to li=
sten carefully and do what sounds best for a particular setting, but I'm cu=
rious if there is a general understanding about this matter.
>
> Cheers! (and Good Recording! which others have used and seems a superior =
salutation)
>
> Steve P
>








<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