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Re: New thread: Low Hz filtering

Subject: Re: New thread: Low Hz filtering
From: "picnet2" picnet2
Date: Sun Apr 5, 2009 5:14 pm ((PDT))
Hi,
    Are you meaning the mic doesn't detect what you hear?
Or is the low frequency content being over emphasized in your recordings?

Such drone can be EQ'ed out - Ive found the proceedure as outlined by
Rob D, in the link below to be very helpful on the subject, although this w=
as
actually a question for the top end of things rather than low:-

http://www.uwm.edu/~type/fieldpostblog/

its the "Equalization Technique for Diffuse Field Recordings" entry if over=
 time
it gets updated...

I tried this today for the NT4 vs a dummy head ive recently built, except
more emphasis was placed on matching the mid and high frequencies
rather than the low - I didnt actually touch the low band other than apply
a low cut filter around 80hz...

http://www.urlme.net/blog/?p=3D803

Brushing water is hardly a nature recording but for this purpose it
demonstrates the EQ of both mics - or rather one being matched roughly to
the other, not that in this case the NT4 is brilliant either..

Click back a couple of steps if you wish to see more details of the head.

I recently built a cylinder microphone that had very specific resonances th=
at
I was able to EQ out, but thats another subject entirely and wrong forum he=
re.

For the MKH 30/40 how much of the wind pickup is due to the mics diaphragm
or the stand its connected to? - wind around the mic stand may also be the=

cause of low frequency effects in addition to structures around it.

BR,
Mike.


--- In  Kevin Colver <> wrote:
>
> I've had the luck to record in a few places with no human noise for
> many, many miles.  There is still low frequency noise from wind, even =

> slight breezes.  My equipment (Sennheiser MKH 30/40) picks it up
> better than my ears.  In the headphones and home in the studio it
> sounds quite loud even though I don't hear it at all with my native
> ears on site.  I've decided that the recording equipment , while
> accurately reproducing what is there, does not accurately reproduce
> what I "hear."  Thus, I don't feel badly about knocking off a little
> on the low end at times if the purpose is for human enjoyment.  Of
> course, this isn't done for recordings made for scientific
> documentation purposes.
> Kevin
>
>
>
>
> On Apr 4, 2009, at 8:48 PM, Steve Pelikan wrote:
>
> > Friends:
> >
> > This is a subject that has been touched on often but never discussed =

> > explicitly (in my memory) and that is low frequency filtering of
> > "ambient" recordings.
> >
> > I've started to get interested in making stereo recordings of entire =

> > "sound scapes" --- meaning whatever is there --- and am in the
> > process of deciding how I'll treat such recordings --- so I'd
> > appreciate other people's opinions.
> >
> > My understanding of the 'elevated' low Hz 'noise' in most settings
> > is that most of it (that I experience) is low Hz man made noise that =

> > carries a long way because of its wave length ( Hi Hz interacts with =

> > "stuff" and disappears rather quickly with distance).
> >
> > When I'm out to document things I record w/o filters. This is in the =

> > eastern US where there's lots of manmade sound. When I want
> > something that "sounds nice" I use (or process with) a low Hz filter =

> > (10 dB to 20 db/ octave starting 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 woodpecker 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 really miss the low Hz stuff.
> >
> > Sorry for this elementary and ambiguous posting/question but it
> > think there is room for some discussion on this topic. In the end we =

> > all need to listen carefully and do what sounds best for a
> > particular setting, but I'm curious if there is a general
> > understanding about this matter.
> >
> > Cheers! (and Good Recording! which others have used and seems a
> > superior salutation)
> >
> > Steve P
> >
> >
> >
>
>
>
>








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