At 8:51 AM -0700 8/29/08, Scott Fraser wrote:
>A good way to determine how realistic your stereo field is, is
>to face a road while a vehicle drives past from far left (or right)
>to the far other side. On playback there should be an absolutely
>linear sense of motion from one side through a well defined center to
>the opposite side. If the car stays mostly in one speaker, then
>abruptly jumps to the other side this may be dramatic but it's not a
>realistic depiction of the stereo field.
Hi Scott-
In addition to the fact that many natural events involve movement,
stereo imaging performance judgements based on trajectory and
momentum might be easier to make than those based on identifying
stationary "clock" positions. The closer the car or other moving
object comes to the mic array, the more depth imaging performance is
involved. There seem to be many qualities, including several
qualities of "motion" to appreciate in stereo imagining. On quiet
nights, my parallel boundary array evenly renders the positions of
vehicles moving through a valley that is 2 miles away and running
perpendicular to the axis of the mics. To my astonishment, the
highway is behind the mic array and all the sound waves from it are
reaching the mics via numerous reflections- none directly.
>This is a problem I hear with many of my older head-mounted
>(quasi-binaural) lavaliere
>recordings, which is a similar set up to a Jecklin or boundary
>separated omni array, & this dictates why the boundary can easily be
>too big for good stereo.
The boundaries in Curt's rigs are quite small and one can adjust the
amount of center mix by adjusting the "set-back" distance from the
capsules to the front edge of the boundaries or "barriers," (the term
Curt prefers). Here's a demo of this: http://tinyurl.com/59emaz Rob
D.
> Omni mics may have more latitude for effective spacing than
>directional mics, but the laws of physics still apply.
>
>Scott Fraser
>
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