Interesting. When a mono source is "placed", what does the software actually
do? I'm sure that it adjusts the differential loudness of the signals coming
from different speakers, but does it also introduce delay and possibly do
some spectral shaping to simulate head related transfer functions (HRTFs)? I
imagine that it depends on the software that is being used.
At 5:22 PM -0400 6/17/04, Lang Elliott wrote:
>Rob:
>
>Might work well. I take it you're talking about a 5.1 setup where the
>"pinpoint" mikes would feed the front center speaker?
No rules really. Phantom positions can work well. Adjusting the
distance from center (radius) is another powerful variable. With a
quad base as a reference, one can place a mono source pretty
accurately in the field, even in a moving field. Often its easiest
to record the "pin-points" in stereo with portable units that are
later "sync'd"
>
>I believe the SASS will capture the low end just fine, especially if you
>used a modified SASS with Sennheiser MKH 20's installed. They have a pretty
>decent low end, although there are other mikes that do better. The SASS
>housing in no way prevents reception of the lows.
I'm fairly manic about the lows. The waves are long and being able to
compare them from two different spots. For sound sources that are
several hundred feet to miles away.
>I'd try that first, before
>adding more low end, but I see nothing at all wrong with adding the
>additional omni and routing lower-than-125 Hz to the sub (and filtering out
>the highs).
Rich is right, anyone actually having a ".2" or any other truly
predictable system is a real problem. How about downloadable file
that is played through one's computer/multiple output sound card with
a number of speaker options/presets. The maker could mix for several
speaker possibilities. This makes a little more sense as a release
medium than DVD standardization which is hardware discrepant and
inflexible. I believe there's a Windows application that plays 5.1 in
some manner. Surround as AC3 streaming is being explored. Or upgrade
to DVD Audio quality in surround somehow. Currently, I play the
bottom end from the L and R channels through a traditional crossover
unit set to 125Hz using two, separately amped, 10" subwoofers. For
above 125Hz, I use five, modest 3-way speakers arranged in a
pentagram. Though I get up and move around, the directionality is
mostly defined by the primary position I'm in when I mix. Rob D.
>Lang
>
>Hi Lang:
>I like the elegance of the four omni strategy too. Do you think
>they'd capture enough low end "body" and textural detail when working
>a large, exterior space? How about this (dream) micing array: a pair
>of opposite facing SASS or four baffled omnis for nearby mid and hi
>frequency sources; a pair of wide spread omnis for triangulating the
>low end and sounds coming from a distance (send <125Hz through
>bi-amped stereo subs) and use 2-4 pinpoint mics for articulating
>spots of textural interest? Rob D.
>
> = ==
>
>At 8:28 AM -0400 6/16/04, Lang Elliott wrote:
>>Rob:
>>
>>Interesting article. Of the techniques listed, the SAM, the
>>Surround-Atmo-Mikrofon (Surround-Ambience-Microphone) array is the closest
>>to what I'm trying to describe. Note that it is designed for ambient hall
>>recording and does not define a front and center. Although it uses
>>directional microphones, it would preserve binaural cues, which I think are
>>critical for what we're trying to accomplish as nature recordists.
>>
>>My design is similar in that it would utilizes four mikes in a symmetrical
>>array, with elements ear-spaced. The big difference is that I would use omni
>>mikes and barriers to make them directional, rather than cardioid mikes. I
>>would choose a design that firmly adheres to binaural psychoacoustical
>>principles, which means that the human brain will be given all the natural
>>information it normally uses to image sounds in space.
>>
>>Lang
>>
>>At 8:30 PM -0700 6/15/04, <> wrote:
>>> > my old idea of mounting 4 mics in a tetrahedral (pyramid shape)
>>>
>>>Kevin,
>>>
>>>Such a system was invented and patented by Michael Gerzon and Peter Craven
>>>back in the early 1970s, and the microphone is now known as the Soundfield
>>>microphone:
>>>http://www.soundfieldusa.com/
>>>The patent is no longer in force.
>>>
>>>It was demonstrated by Gerzon that a tetrahedral array of loudspeakers is
> >>NOT the best way to reproduce the signals. Although the
>microphone captures
>>>information that includes height information, the height information is
>>>almost never reproduced (unfortunately). For practical reasons almost all
>>>reproduction systems involve a horizontal circle of loudspeakers, say 6 or
>>>8, or even more.
>>>
>>>I have used a Soundfield microphone, either the commercial one or one
>>>assembled out of individual microphones, to make numerous nature recordings
>>>and I find it very satisfactory for my purposes. But it is not without
>>>flaws. A great deal more information can be found at:
>>>http://www.ambisonic.net/
>>>and in the more than 100 technical papers on the subject published in the
>>>Journal of the Audio Engineering Society, and elsewhere.
>>>
>>>Eric Benjamin
>>
>>Enjoyed this discussion. The below website has quite a few 5.1 micing
>>diagrams including the soundfield:
>>http://www.mtsu.edu/~dsmitche/rim456/Materials/tracking_5_1.html
>>Rob D.
>>
>> = = =
>>
>>
>>
>>
>>
>>
>>
>>[Non-text portions of this message have been removed]
>>
>>
>>
>>
>>"Microphones are not ears,
>>Loudspeakers are not birds,
>>A listening room is not nature."
>>Klas Strandberg
>>Yahoo! Groups Links
>>
>>
>>
>>
>
>
>
>
>
>[Non-text portions of this message have been removed]
>
>
>
>
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links
>
>
>
>
[Non-text portions of this message have been removed]
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