Friends:
I've been slowly going through the great tests/comparisons of
microphones and recorders that people have made available. These are
very helpful, but I still have lots of questions about what I'm looking
at and hearing.
Here's a starter question. I viewed Rob Danielson's comparison of Rode
NT1-A's with Shure 183's and Rode NT-4's. This is at the page:
http://www.uwm.edu/~type/audio-art-tech-gallery/pages/page_37.html
The overall noise levels I hear agree qualitatively with the output
noise spec's I've found for these microphones. I was fascinated to hear
the different quality of the noises.
It seems that the power spectrum (is that what it is called?) of the
NT1-A recordings all have a large peak at approx 13 KHz (independent of
preamp used and recorder) while this peak is absent from the displays
for the other microphones.
Based on what I can see, I attribute the signal the the NT1-A's. Is that
reasonable? Am I correct in thinking that this signal is pretty
significant in magnitude but not reflected in the A-weighted output
noise measure because it is either 1) at a pretty high frequency or 2)
in a narrow frequency range?
Is this sort of signal generally common in many microphones or usually
unique to particular models (eg. NT1-A's) or is it more reasonable to
attribute it to the individual microphones used and not to entire models?
Thanks,
Steve Pelikan
|