At 12:48 PM -0400 7/18/05, Walter Knapp wrote:
>From: Rob Danielson <>
>
>> I'd venture to guess that a large part of what many regard as
>> ambience has to do with clarity (more tones, better separation)
>> between 125 and 700hz. I seem to consistently get more of this from
>> these mics, so along with their lower noise, they have become my best
> > option.
<snip>
>
>If I remember right shure talks of a dip in sensitivity in this area
>with the 183's. Something to do with improving the sound quality.
The phenomenon I am trying to describe is not a matter of frequency
response but one of tonal and dynamic clarity. The NT1-A produces
more, distinct tones in this range. I can hear fewer, more sustained
harmonic tones within this spectrum in your mkh30/40 chorus frog
sample. When I listen to your MKH 80 sample, they're not there. The
NT1A's are more similar to the 80's in this regard.
I'm not certain where these exaggerated tones come from and mkh mics
are not alone in producing them. I enjoy trying to capture acoustic
space. Distortion in the lower mids is much, much less of an issue
for folks recording isolated calls. The exaggeration masks spatial
information between 125-700 Hz in all of my high gain location
recordings from 15dB to 50dB ambient levels dBA.
Of course, the 183's are not in the same class with ~23dbA self
noise. In my tests that included the 183 with the mkh 30/40, there
was no significant dip in response in this range. You may be
thinking of the 184 or 185 which have low end off probably to
compensate for proximity effect as a lav.
>
>The polar patterns of the Rode are likely not as smooth as higher end
>mics, this may or may not be a problem depending on what you are
>recording. Seems like you are finding the polar patterns of the Rode a
>little narrower than the MKH as a general finding?
Yes, considerably with the NT1A. In the field, 2- NT1A's used in x-y
cover ~120 degrees (within 3-4dB at 8KHz). From the spec sheet for
the MKH40, two of these in X-Y would easily cover 180 degrees within
5dB at 8K. You can hear the volume and pitch in the center of the
stereo field drop of in the night sequence mp3. I checked my field
notes again and found that the NT1A's were angled at 90 degrees
instead of the usual 60. Turkeys had roosted in a nearby tree the
previous night so widened the angle a bit and didn't want to lose a
tree that I know owls favor on the other side. I've learned to regard
them as more directional than any standard, cardioid mic I've used--
nothing like a shotgun though.
There's more than one "Rode" I'm using. The NT2-A is multi-pattern
(7dBA self noise) and seems to have wider coverage in the cardioid
setting but I can't afford another at this point to couple two in MS
or spaced omnis. I've only gone out with a Nt1A/2A M-S rig 3 times
and I haven't mixed anything from it yet.
>Though you have only
>limited experience with the range of MKH mics.
I've used the 20, 30, 40, 60, 70. 816-- gosh, some of these for over
25 years. Its the 80/800 I've not had the pleasure of meeting and
would like to.
> > If you decide to dive into NT1A's, it might be a good idea to tell
>> the dealer that you intend to take them out into the field and that
>> you have heard that some units can test to be more vulnerable to
>> moisture and handling noise. Take them to a swamp or steamy bath room
>> and give em a 100% warm or hot humidity test. A bad mic will produce
>> fizz and signal break-up after a while. For the handling test, I
>> guess you could gently vibrate them in your hands and see if this
>> creates about the same amount of signal disruption on both mics.(This
>> will sound awful, you're seeing if they respond about the same to
>> vibration). You're not taking a huge risk, but out of the eight I've
>> bought, I did sent one back that I felt should have performed better
>> and the dealer was fine with this.
>
>I work such that all my mic setups must be hand holdable, and I use them
>that way very often. When buying a new mic it's a good idea to think
>through how you will suspend and wind protect the mic. This is going to
>be especially true with big, heavy mics like the Rode. A bare mic is
>only part of a nature recording setup.
You're right, I should get some pictures together with an DIY mount
solution using 4" thin wall PVC and 1/2' pvc fittings and long fiber
fake fur for ~$8 each in materials. I know the NT1-A's are very
comparable to the MKH's in terms of handling and wind because I look
at 4 channels comparing this all the time. My mount is "hand
holdable," but its very hard for _any_ mount to be hand held without
making any low Hz bumps with sensitive mics like we're discussing.
I've also done a modification to the NT1A with shoe goo flipping it
90 degrees so it is front-facing and mountable in the more usual,
horizontal position. With the pair I modified, it lowered handling
noise for some reason.
>
>> It is mind boggling what could be possible with low noise mics, a
>> Rolls pb224 and consumer recorders. I love my 744 and I'm pretty
>> sure that the extra bits play a big role when it comes to coaxing
>> body out of quiet settings. The background ambience bottoms at about
>> 20dB that night by the river. That said, the gain on the NH900 is so
>> impressive, its possible that the extra saturation one can pour into
>> the 16 bits initially (with a high sensitivity, low noise mic and the
>> rolls pb224) will also help one get more body, better local acoustic
>> etc. There are lots more mics on the list of options to consider now.
>> Your AKG could take on a new personality.
>
>Of course part of this is experience.
Not sure field experience is crucial for testing new mics for
possible bugs or using a PB224.
The test I referring suggests that the noise floor of an NH-900's
HiMD's internal mic pre is in the neighborhood of the self noise of
an NT1A, or ~7dBA? That's is a pretty significant find for folks who
are after low noise performance assuming my mic->phantom supply->
recorder combination isn't highly unique. Its very possible, the
older Sony MD's will benefit as well for noise, phantom-powered mics.
I'm referring to this test:
http://www.uwm.edu/~type/Mic%20Preamps/RollsPB224-%3eHiMDMicPreAIF.mov
Rob D.
>It's been noted before that
>experienced recordists can coax more from their equipment than
>beginners. That's why I keep telling folks to get out and record as much
>as they can. And that one should spend some time recording with a piece
>of equipment before coming to final conclusions. I don't figure I'm
>anywhere near getting the best out of a mic until I've used it at least
>a season or two.
>
>Walt
>
>
--
Rob Danielson
Film Department
University of Wisconsin-Milwaukee
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