Hello--
I would say, so situationally, technically and perceptually complex,
that determining what works best for our personal needs results in an
on-going learning process about mic and pre combinations.
The reference number we have discussed for years as a possible
maximum in mic self-noise performance is 16 dB(A) or better (lower
number) for nature work. Supportive conditions include not having to
use full or near full record gain to get adequate file saturation.
Similarly, 10 dB(A) or lower has also been suggested for quiet
natural locations where there may be periods of time when there are
no or very distant human-made intrusions via land, sea or air and
there's no wind, surf or other loud source of natural background
ambience. Settings with considerable high frequency background
content such as insects, vegetation "sizzling" and others will mask
or cover up a good part of typical mic self-noise "hiss." Self-noise
that occurs low in the frequency spectrum has a "roar" quality that
is more audible and more effectively obscures the spatiality of
recordings.
The noise ratings and computations, like those on the Rane Table 3,
http://rane.com/note148.html rarely match real world noise
performance. The Rane chart is great in aiding understanding about
the basic relationships but when it comes to investing a good bit of
money for long term uses, only side by side comparisons can make one
sure of the typical noise performance one will get. Even if we use
measurements Raimund and others provide us, they still leave us with
ballpark estimations. Our ears are a better judge if we have careful
comparisons to work with. (Our ears are not nearly as reliable at
judging subtle qualities in a single stimulus like one recording
without a reference, although tons of prectice helps).
For example, a number of folks have measured Hi-MD input noise and
the MKH-40 is a common self-noise reference. Using Table 3, this mic
computes to a noise floor of about -111dBu (A weighted) and even
though the Hi-MD pre's input noise is -124dBu, a difference well
above the suggested amount of 10dB, one can still hear the recorder's
input noise faintly behind that of the mic's self-noise when maximum
gain is used.
What does a difference of a few dB's sound like? As a rule, one can
detect a change of about .5 dB. Some use a value of 1dB. So, at max
gain, in a quiet location, one should be able to detect from 5-10
steps of noise between 17 dB(A) for the M10's capsules and 22 dB(A)
for the DPA 4060's. If you are recording a fairly robust sound like
the ocean surf or a bird locked in at 15-30 feet where you don't need
full or near full pre gain, you probably won't be able to hear any
noise difference.
Why obsess about extremely low-noise performance? I feel its because
of the appeals of spatial characteristics one cannot hear and
appreciate unless the actual background sounds are very minimal-- low
enough that subtleties like soft reflections are not masked. Only
very low noise gear can capture this and more and more folks are
inspired by such results.
We know that the pocket recorder manufacturers do not have this goal
in mind,.. but that doesn't seem to keep us from hoping. ;-)
This scrapes the surface on the subject and it makes me think that
sequence comparing the below mics going through the same, low noise
pre at high gain could be useful:
ECM-55 or Panasonic WM61-A's
WL183
DPA 4060
Capsules liberated from a M10
EM-23
MKH-40
MKH-30
MKH-60 or MKH-70
ME-66 or 67
MKH-20
NT2000
NT1-A
Rob D.
= = =
At 9:16 AM -0800 11/15/09, Bernie Krause wrote:
>
>
>You know, Robin, it's all a compromise: price vs quality, one set of
>ears vs another, field sites with lots of signal vs quieter ones,
>noise floor vs transparency. There is no absolute. Just a matter of
>preference.
>
>Bernie
>
>On Nov 15, 2009, at 6:59 AM, Robin wrote:
>
>> I know the DPA 4060 are small and have a nice frequency response,
>> but the noise seems too much. By my calculations the EIN is -103
> > dBu(A). The low-sensitivity 4061 seems a better deal at -110 dBu(A),
>> so long as you have enough clean gain in the recorder. Aren't there
> > quieter options?
>>
>> I am confused in this regard; my respect for Chris Watson, Bernie
>> Krause, etc. encourages me to understand their choices.
>>
>> -- robin
>>
>>
>>
>>
>> ------------------------------------
>>
>> "While a picture is worth a thousand words, a
>> sound is worth a thousand pictures." R. Murray Schafer via Bernie
>> Krause
>> Yahoo! Groups Links
>>
>>
>>
>>
>
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