At 11:25 PM +0000 3/11/10, thesilverloon wrote:
>
>Thanks David,
>Its my intention to use twin AT4022 mics with the Sony PCM M-10 and
>the Art Phantom 11 power supply. I would like to build a spaced
>timber baffle, to mount the mics. Are you able to tell me on the rig
>that you used, the distance between the mics, and the setback from
>the leading edge?
Here's a study on the affect of setback distance with high frequency sounds=
:
http://diystereoboundarymics.blogspot.com/2006/12/studying-inset-variable-o=
f-small.html
>I realize that there are many variations out there, but being non
>tech I have to start some where. If anyone else in this group has
>built similar, please feel free to respond. One last question. What
>is the audio difference between the above and using the AT4022's in
>a modified Crown SASS unit?
Walt Knapp's modified SASS rigs are Crown-made housings with lower
noise omni mics fit into them. I think there could be some special
qualities to SASS rigs that can't be easily emulated DIY.
Experimenter Allan Haighton found form the audio performance of the
foam "nose" on the SASS hard to replicate. Boundary arrays are not as
well understood as one might think. I don't own a SASS so I've never
been able to compare it straight-up with other arrays. Like Curt, I
did make and try some "Pseudo SASS" arrays. Here's a comparison test
with one:
http://tinyurl.com/ylxcol4
Here's just the Parallel Boundary (PB) vs. Pseudo SASS segments
looped so you can judge differences more easily:
http://tinyurl.com/y89t7wt
The two rigs have the same omni mic capsules in them. I feel there is
more left-right contrast in the Parallel Boundary (PB) rig. The steps
across the stereo field produced by the Pseudo SASS seem more even
than those of the PB rig but PB's stereo image feels wider, more
horizontal (the max sound spread in the test set-up is 180 degrees).
Both of these traits may be contributing to what Curt describes as
more "spaciousness" in the PB array. The amplitude at the center of
the stereo field also drops off a bit with the PB array which can
create a sense of more depth in the center. This can be aesthetically
appealing but less accurate. Note that in this test layout, the
center is actually _closer_ than the sides. The center of the stereo
field is slightly brighter and more accurate with the Pseudo SASS.
The brighter edges of the PB rig probably stem from the additional
reflections of the perpendicular to boundary orientation. Again, the
indications are that real, Crown SASS rigs perform differently.
Also note that this comparison doesn't test frequency
response/imaging under 500 Hz very well and this region can be
crucial for imaging large acoustic spaces.
I feel that we have things to learn about the effects of stereo array
design on tonality and, consequently, tonality on spaciousness.
Boundary mics make this more apparent. Incidentally, they're not
widely used or accepted. Rob D.
>
>Many Thanks,
>
>Paul
>
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