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Re: Stereo Patterns

Subject: Re: Stereo Patterns
From: Rob Danielson <>
Date: Fri, 28 Apr 2006 10:31:24 -0500
At 2:11 PM +0000 4/28/06, Rich Peet wrote:
>--- In  Rob Danielson <> wrote:
>
>>  Hi Rich-- Do you recall if the barrier was aligned with a hollow, a
>>  line of trees, or other depression? I'm getting an image of
>>  reflections moving away, down the middle of the stereo field. Segment
>>  1 is my fav. Rob D.
>>
>
>The mic was in an oblong clearing surrounded by "big woods" that are
>just starting to leaf out. The big woods was a full canopy with no
>understory.

Hi Rich--
If the array was aligned with the oblong dimension of the space, 
sample 1 could be an indication of the off-axis detail the rig is 
capable of. These, four particular mics seem to be representing the 
lowest octaves with differences. To my ears, 2 & 4 are most closely 
matched. 1/3 less so with each other and the other pair. Of course, 
recording deep space in a remote location places great demands on 
mics-- more than any other event I've tried to record and careful EQ 
can restore quite a bit of balance. One advantage of M/S is its a bit 
easier to obtain tonal balance.

>  This is the type of land that you would expect to find
>this Red-headed Woodpecker pair.  I can confirm the call of the
>Red-headed but can not say that I have confirmed beyond a doubt that
>the drumming is the mate.  I need to rule out Red-bellied on the
>drumming yet. The other main charector is a Chipping Sparrow.
>
>I am a fan of 180 degree barriers for omni's in natural space as the
>"Cube" is an evolution of the "Block head". Cardiod mics seem to favor
>90 degree patterns for stereo which is an indication of its weakness
>in my eye.

Mic technology has a ways to go before I'll be happy with the ability 
to account for sound impressions equally in all directions. Omni is a 
distinct polar pattern too.

Miciing array choice could, out of love and obsession, be based on 
the aspects of the location/experience one is gives priority. I hear 
what might be local geography, you hear what might be a distant mate. 
When I place a boundary next to my an ear, 800-2300 Hz+ is 
attenuated, but the boundary can bring out more hi Hz localization.

A barrier in a stereo or quad doesn't address the lower register 
challenges well enough for me to use a "fixed" array in the field. It 
might lessen my ability to adjust to the specific conditions.  E.G. 
I'm going to get plenty of highway 131 whether I direct a cardioid, 
omni or parabolic dish anywhere near its direction.  If I take this 
for granted, I might be able to get enough of the highway's sounds 
reflected from a hill 1/4 mile away to make the recording a tad more 
illustrative of the space.

At the moment I'm more obsessed with the impression of depth and form 
than Hi Hz localization-- but with current gear, even a passionate 
listener might find either distinction, "pushing the limits," to put 
it nicely.

Can you think of a way to measure the percentage of the sonic energy 
in your recording that is below 700Hz?  studying passages with and 
without the chipping sparrow might be useful. My suspicion is, in the 
frequencies that give body and character to sample no 1, the polar 
patterns of cardiods and omnis might be a lot closer than one might 
think.

Martyn hinted at another challenge. Perhaps one reason recordist 
argue for certain rigs/arrray is because its so hard to tell in the 
field what the heck one is actually getting even if one takes time to 
change positions mics/mic types Its a huge, often futile chore 
because what sounded interesting in the field can often sound much 
less interesting than another experiment tested only for a few 
minutes.  Time in the field is precious, I can spend it really trying 
to listen with my best system (my ears) or monitoring through 
headphones to a much inferior system.  In my studio with headphones 
and two speaker systems to compare, I can become a lot more objective 
"distant" and hear aspects in the recording I could not hear in the 
field.  Maybe we stick with a set-up for a while because it helps us 
learn the rigs characteristics faster in the varied world we go into?

  = = =

>   The strength of the "cube" is that I can pick between two
>180 degree pairs and I would have setup the "block-head" 90 degrees
>off at this site if I would have used that.  The "block-head" is
>currently on loan to Curt to use as a comparison in further testing of
>his "Wedge".

That should be interesting.   Maybe a telescoping separator between 
the boundaries?  Brian's 20" spread suggested to me that something is 
going on with timing differences beyond what we've tried to 
understand thus far. Rob D.

>Rich



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