At 3:01 PM -0700 8/26/10, Marcus Buick wrote:
>...
>
>[(9) Positioning localized, low frequency sounds
>(<~125Hz) in the center of the
>stereo field creates more options in post production compared to side
>positioning.]
>
>I think in theory this is correct, however, because low frequency sounds a=
re
>omni-directional, the SPL of the low frequency content is probably of more
>concern. In post I would prefer a louder low frequency in one mic, than a
>centered, barely audible, low frequency signal in both. Because the abilit=
y to
>center an image in post is easy, I would focus my efforts on capturing the
>greatest amount of low frequency content in the
>field and worry about the image
>later.
Hi Marcus--
I think the advantage is most evident when the
Low Hz is arriving from one direction and with
greater than desired presence. As you describe,
because <125 Hz is largely omni-directional and a
high percentage is common to both mics, in phase,
its can be isolated and effectively addressed in
the center of the stereo field using L/R to MS ->
Stereo EQ -> MS to L/R processing allowing the
out of phase bass to be preserved and enhanced on
the sides. I use this processing all the time in
post now because its quite useful at obtaining
more sense of depth in the center of the field.
>(10) That stereo imaging can involve active participation on the part of t=
he
>listener. Thus, a recordist gets "better" at processing the "cues" provide=
d by
>the arrays she/he uses.
>
>Absolutely! It=C2=B9s the reason I love my Schoeps so much!
>
>An interesting side note: a paper written by Eugene Brandewie and Pavel
>Zahorika, in the JASA titled, Prior listening in rooms improves speech
>intelligibility, indicates that acoustic effects of a single re=C3=BEectio=
n are
>perceptually suppressed after repeated exposure
>to a particular con=C3=9Eguration of
>source and re=C3=BEection.
Can you elaborate on "the acoustic effects of a single re=C3=BEection?"
>
>Results from 14 listeners indicate that with
>prior room exposure, masked speech
>reception thresholds were on average 2.7 dB lower than thresholds without
>exposure, an improvement in intelligibility of over 18%.
>
>This effect, which is shown to be absent in anechoic space and greatly red=
uced
>under monaural listening conditions, demonstrates that prior binaural expo=
sure
>to reverberant rooms can improve speech intelligibility, perhaps due to a
>process of perceptual adaptation to the acoustics of the listening room.
Noisy workplaces are good examples. People also
use places in rooms where the sound waves are
most confused to "hide" from the content of the
sounds and retreat. Outdoors, small mammals adapt
their vocalizations to be more easily masked by
environmental sounds. Owls and coyotes seem to
recognize when calling spots carry well and
return to use them as places they can make longer
range contacts. They also hang out in places
where man made sounds have shorter decays etc.
>
>I believe this effect is also present when listening to music or any compl=
ex
>recording, and the inverse of this seems to be true as well, i.e. that wit=
h
>repeated exposure to any recording process, the listener=C2=B9s ears hear =
more of
>what they want their mics to capture, than
>everything the mics actually =C2=8Chear=C2=B9.
>Basically what you said Rob, that a recordist gets "better" at processing =
the
>"cues" provided by the arrays she/he uses.
I think this also means that as recordists, we
are at our best when we continue to experiment
with and expand upon our "performance" options.
Recordists who do comparative field testing of
their new ideas and established arrays they have
less experience with always comment how much it
accelerates their understandings and interest in
making improvements. Rob D.
--
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