I hate replying to my own message, but this brings up another consideration=
with the EM172 capsules that I wasn't able to test to my satisfaction, eit=
her: bias voltage.
Along with Ricardo Lee's paper on wiring EM172 mics into XLR plugs, there'=
s a nice set of tables on the micbuilders group documenting the effect of b=
ias voltage on the microphone's sensitivity and self-noise (Files/EM172/Pri=
mo EM172 Sens Noise vs RL VL.pdf).
The upshot is that the EM172 is designed to take a wide range of bias volt=
ages, and will work with numbers as low as 2V and as high as 10V. But the s=
ensitivity and noise floor improves at higher voltages.
I ran the numbers on my recorders as well as the Sony M10 to see if using =
a 9V battery box would be an improvement over the stock PiP from the record=
er. Based on those numbers my expectations are that you really are better u=
sing XLR inputs on the Tascam (mostly because of the lower gain on the 3.5m=
m input), but that there are real gains to be had on the Sonys. The M10 sen=
sitivity would improve by less than a dB, noise floor would improve by abou=
t 1.5dB, and overall signal to noise would bump by about 2dB. The input imp=
edance of the PCM-D100 is beyond the range of the graph, but it would see s=
imilar improvements to the M10.
I wound up getting a 9V battery box from Church Audio, but since it doesn'=
t really offer much in the way of improvements on the Tascam gear I own, I'=
ve never used it. It may make an audible difference on an M10 or on a PCM-D=
100, but I can't know without testing.
The XLR build I did on my EM172 mics is set up to provide just over 9V to =
the capsules. That was intentional, in an effort to wring as much performan=
ce out of the EM172 capsules as I possibly could.
Tom
"While a picture is worth a thousand words, a
sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause.
------------------------------------------------------------------------
Yahoo Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/naturerecordists/
<*> Your email settings:
Digest Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/naturerecordists/join
(Yahoo! ID required)
<*> To change settings via email:
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo Groups is subject to:
https://info.yahoo.com/legal/us/yahoo/utos/terms/
------------------------------------------------------------------------
|