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Re: Coloration

Subject: Re: Coloration
From: Walter Knapp <>
Date: Sat, 21 Feb 2004 15:39:58 -0500
From: "Kevin J. Colver" <>

> There are also situations where this high frequency amplification is not
> desired.  For example, if there are high frequency sounds behind or in
> front of the subject these will also be greatly magnified.  All of the
> higher frequency sounds in an imaginary cone extending outward from the
> parabola will be magnified.  This often happens with 1) breeze or wind
> in rustling leaves in front of or behind the subject, 2) many other
> birds within the directional path of the parabola but not necessarily
> near the subject desired, 3) crickets or cicadas within the path of the
> parabola that become greatly magnified beyond what would be heard in an
> omni mic placed near the subject.
> 
> A second situation where the parabolic effect of bringing the subject's
> high frequency sounds close preferentially over the low frequencies is
> not desirable occurs when the subject has significant aspects of the
> sound in both high and low frequencies.  A bull elk bugling, a gurgling
> stream, or waves in a tide pool are all situations where the
> amplification from a distance of the high frequencies but not of the low
> frequencies will distort the end effect.

One should note that the alternative, a shotgun mic, also has a 
narrowing directional cone with frequency increase. And due to the shift 
to low frequencies with distance it's going to also not be truly 
representing the call either. Just recording at a distance contains 
changes, we should not expect the same result as putting a mic right in 
front of our caller. Even the parabolic only approximates that.

What I could really use is a mic that's highly directional at all 
frequencies, or at least at the lower end. That's much tougher to come 
up with. But so much of the interfering noise is low frequency it would 
really help.

> That said, my recordings with my Telinga Stereo DAT are, in my opinion,
> just awesome and I greatly appreciate your creation and highly recommend
> it to others planning directional recording work.  

I will second this. It's almost in a class by itself, separate from 
other parabolics.

> I do often reduce the higher frequencies by 3-5 dB later in my studio to
> adjust for the inherent parabolic effect.  I do not consider this a
> problem or a nuisance. I clean up my recordings, cut out the garbage
> such as stomach sounds, trim the unwanted silence, fade in and fade out,
> and tweek the EQ a bit before archiving them.  This is just a routine
> part of my housekeeping and I do not consider it a burden.

I don't specifically try to undo the parabolic effect, but do a bunch of 
routine stuff to all recordings too. Just part of the process.

Walt




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