At 4:06 PM +0000 7/6/09, Matt Blaze wrote:
>--- In
><naturerecordists%40yahoogroups.com>=
m,
>Rob Danielson <> wrote:
>>> Hi Matt--
>> Thanks for sharing your explorations. The SF Bay recording was the
>> most successful comparison subject for me because of the width of the
>> stereo field and abundance of tones to regard. I appreciate the
>> additional work of setting-up to roll three recorders all at once.
>>
>> There seem to be fairly significant tonal response differences
>> between the mics used in this test that make comparing stereo array
>> differences a challenge. If you are able to access a pair of
>> MKH-800's, array differences might be more apparent if you used these
>> two mics in as many of the arrays as possible. I think the advantages
>> of employing the same capsules in the arrays outweigh the advantages
>> of capturing the same moments. One can often find similar passages to
>> compare if you record each test segment for 10-30 minutes.
>>
>> I like the choices of arrays that you are working with and hope that
>> you'll keep us abreast of these studies. Rob D.
>>
>> --
>>
>
>Rob,
>
>Thanks for the reply. I agree -- in many cases these are very
>different mics, and what we're hearing is as much due to the
>different models' wide variance in response curves and overall
>quality as to the configurations. On the other hand, for some of
>the subjects, there's just no substitute for simultaneous recordings
>in exposing the differences in the images. In the woods example,
>for instance, if you listen to the first few seconds of each clip,
>the level and position of the bird call on the right is very
>different in the three recordings. Knowing that they were recorded
>at (about) the same position and the same time is rather revealing
>about the images produced.
>
>There doesn't seem to be any right answer, short of winning the
>lottery (always a good strategy!) and getting a few more pairs of
>MKH800s. Actually even that is problematic -- the 800's seem
>to be usable outdoors only inside a blimp. They are by far
>the most wind and shock sensitive mics in my arsenal.
>
>It occurs to me that the *right* way to do this would be to use
>a bunch of Ambisonic-type microphones, say 2 on a Jecklin
>disk and another two at some spacing. That could simulate
>XY, Jecklin, some spaced directional configurations, maybe more,
>with similar coloration and response characteristics in all of
>them.
>
>But that would involve at least three new mics, plus hauling
>at least 16 channels of sample-synchronized capture around, so
>it won't be happening any time soon for me...
>
>Best,
>
>-matt
>
>mab blogs at <http://www.crypto.com/blog>http://www.crypto.com/blog
>
Hi Matt-
I see that Mike is using matched EM-158's
http://www.urlme.net/blog/?p=3D981 each) to compare his arrays
with the ability to roll several recorders as once. These capsules
seem to be a good solution for omni based array comparisons. Maybe
I'm not following your thinking, but the Ambisonic rigs are very
exceptional in design, not really made for use in different array
configurations.
To me, what is unique about your capability is being able to employ
very low noise, well-known and respected mics _and_ include popular
figure 8 based arrays like M-S and Blumlein. Wind sensitivity aside,
I can't think of a better pair of mics than mkh-800's to use for
thorough array testing. :-)
As for sound source uniformity, with a pocket pink noise generator
like Mike uses (though it could have a little more low Hz) and a
quiet place at night one can conduct a 24 position location clock
test at distance of about 100' and generate very instructive results.
We used this technique for an array/mics localization test during the
Recordist Camp Out. I'm waiting for more folks to get their files to
me before I compile the master
Note, however, that we also used different rigs/mics so the results
only indirectly help one learn about stereo array performance
differences. Of course a capsule's polar pattern plays a key role in
array performance but the few comparisons I've listened to suggest
that tonal response plays a significant role in spatial imaging too.
Rob D.
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