At 12:09 AM +0000 7/6/08, Greg Simmons wrote:
>--- In
><naturerecordists%40yahoogroups.com>
>Rob Danielson <>
>wrote:
>
>> (Here's a copy of the article I
>> scanned through
>>
>><http://www.audiosignal.co.uk/Resources/Stereo_shuffling_A4.pdf>http://www.audiosignal.co.uk/Resources/Stereo_shuffling_A4.pdf)
>
>That's the article I was referring to...
>
>> Wouldn't the LS-10
>> recorder have to be employing spatial
>> equalization (shuffling) under 600 Hz to achieve
>> these benefits?
>
>Good question! Gerzon wrote: "The use of bass-widening up to 600Hz
>with this technique seems to give a much better sense of space than
>the use of ORTF technique, and without the latter's 'phasiness'
>anomalies." I am not sure whether he meant the 5cm technique with
>bass-widening was better than ORTF without bass-widening; I'm also
>not sure whether or not he was saying the bass-widening was essential
>for the 5cm technique to work, or whether it was just a worthwhile
>enhancement.
>
>> I saw mention that the lowest octaves seem to
>> play a larger role in the enhancement technique
>> and signal captured with the LS-10's internal
>> mics seems to have considerable low frequency
>> roll-off under 100Hz (probably to reduce handling
>> noise).
>
>Especially with coincident techniques, where at low frequencies both
>capsules capture the same signal. As the mics are moved further
>apart, the 'roll-off' from stereo to mono gets lower in frequency
>and, theoretically, so does the roll-off point for the shuffling. But
>at the same time, pinpoint imaging decreases.
>
>The 5cm spacing and angling of the capsules might offer a good
>compromise between the two - with or without bass-widening.
>
>As for the LS10's 100Hz roll-off, it would only be a problem for
>sounds that included important content down there!
Biologically, animals live in and hear low frequencies and react to
them. Spatially, the lowest frequencies almost always establish the
greatest distances in recordings. A mic rig with very poor response
under 125Hz is a pretty limited in my understanding of field
recording.
>
>> Most stereo arrays should be able to capture the
>> spatial cues Greg Peterson and I assessed in his
>> Brush Warbler recording. To my ears, Vicki's
>> Shure 183 rig which positions two omni
>> forward-facing at ear spacing exhibited a
>> significantly a wider stereo field over the
>> built-in array in her LS-10.
>
>Are you referring to speaker listening, or headphones?
Both.
>
>> In a couple of cases when we attempted to
>> evaluate stereo imaging between different arrays
>> on this list, people's preferences varied more
>> than I would have guessed.
>
>It becomes highly subjective with many factors that need to be
>defined, beginning with a definition and consensus of what is meant
>by 'stereo imaging' itself. Some people's concept of 'stereo imaging'
>means pin-point localisation of individual sounds, and they'll
>naturally prefer recordings that offer this. Other people's concept
>is a sense of immersion in the recording, a sense of space or
>spaciousness. From a stereo miking point of view, pin-point
>localisation and spaciousness are often inversely proportional - the
>factors required to create pin-point localisation do so at the
>expense of spaciousness.
Its very true that some listeners confuse spatial documentation with
"spaciousness" or immersion in reverb.
I think it might be possible to judge array performance on
localization, depth and analysis of the local sound reflections. The
tests would have to be done at several distances in the range of 20'
to 500', in a relatively open space, and with low, consistent ambient
background levels to capture sufficient detail.
>
>Then there is the question of speaker or headphone playback. Few
>stereo techniques work well in both playback situations.
Both are necessary, but headphones might provide a more reliable
reference-- especially if we could narrow it down to some good
affordable models.
>
>[As an aside to this: when I record direct-to-stereo albums for
>acoustic musicians, one of the first things I do is ask the client to
>play me some recordings they like the sound of. I ask why they like
>those recordings, and I also take note of how the client mostly
>listens to music - through speakers or headphones. This helps me to
>choose the most appropriate stereo technique; one that will give the
>client the desired sound.]
>
>> That doesn't mean we
>> couldn't learn a lot from more testing/comparing
>> stereo array performance-- but I do think the
>> tests would have to be done very carefully for
>> one to come away with observations that would but
>> widely agreed upon.
>
>I wonder if they could ever be widely agreed upon!
My goal would be to have a much better understanding of what
different arrays are doing-- their strengths and weaknesses.
Some recordists adopt a few mics and rigs and stick with them for
years. Other recordists change their goals as they develop their
art-- they want to hear/record in many different ways and
experimenting with arrays is a very good way to do this. Rob D.
--
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