First, I would like to thank Dan Dugan for lending a Sony MS957 mic
and to Nick Roast for letting me include the FELS in the test.
Below is a link to a test made as a follow-up to our discussions
about how self noise from consumer grade (MD, HiMD, Walkman DATs etc)
mic preamplifiers might be detracting from the spatial transparency
in recordings made with high record level gain in quiet locations.
Nick and others suggested that boosting a mic's output 20 dB with a
FELS unit before the PIP mic pre could help reduce noise similar to
the way higher mic sensitivity (effective output level) can.
There was also the possibility asserted that most of today's built-in
mic pres are "good" so one would not expect a lot quality gain using
an external mic pre and the MD's analog line iput. I included a test
with a Sound Devices MP2 with Rode NT1A's for this comparison.
Sorry, I didn't have the cables I needed to run one of the other
higher noise PIP mics through the MP2 which would have made a better
comparison. A pair of NT1A's are in the same price range though.
I guess the test can also be used to judge a particular type of
performance between some of the mics often discussed at the entry
level. This test assumes you're after spatial transparency in
relatively quiet location recordings-- not to be confused foreground
recordings of individual calls or uses in much louder urban spaces,
etc. The Marshall VM63 mic is used only because Nick sent me a very
compact FELS unit that works only with mono mics. Its not really a
mic I recall us talking about before but I needed a mono battery
powered mic which the FELS requires.
Recordings were made at 16 bit PCM on the HiMD so I've kept them at
full resolution to eliminate other variables. No EQ, of course. I
tried to match the levels psycho-acoustically and som of the levels
seem a little different without the headphones I used. You can still
make distinctions, I think.
The test is a BIG 33mb QuickTime movie. Sorry Dial- Uppers!
http://www.uwm.edu/~type/Mic%20Preamps/Mic&PreTransparencyTests/media/Trans=
Mic&PreTestsSor3_01.mov
If your browser needs a free, QuickTime plug or update:
http://www.apple.com/quicktime/download/
You should be able to use "save as QT movie" with the button on the
far right of the movie window after it fully loads. Any one up for
making some spectral pictures? Rob D.
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Rob Danielson
Film Department
University of Wisconsin-Milwaukee
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