From: Rob Danielson <>
> The cheaper pip mic options red to have have noise that spreads
> across the spectrum though. The panasonic wm-61a and the NT-4 in my
> clock test exhibit this. The Shure 183 and KM-23 are exceptions.
> Hopefully we'll find others.
In reading specs I've seen others from time to time. Only field
experience will tell which are useful.
I was not talking about what part of the frequency self noise occupies,
but how it sounds, that's a different thing. It may very well be that
the easiest to hide self noise is one that's also even across all
frequencies.
> It seems to me that making low noise recordings in quiet locations
> always calls upon three factors.
> Mic self noise: spec'd as __dB(A);
> Moc Sensitivty: spec'd as __mv/Pa;
> Mic Premp Effective self noise at current setting: e.g. PIP/MD gain of "2=
3"
There is no set value for such a general statement. Look below at the
wind up recorder and dynamic mic, they did it. The values mostly just
are a measure of how easy, or hard it might be, and even then are not a
direct measure.
Since it's always possible to attenuate things, or to introduce noise
it's more that you are defining just how wide a range of subjects and
sites you can record. Some easily, some hard, some nearly impossible,
for any given set of specs.
Certainly mic sensitivity is important, but it can be gotten around much
easier than self noise.
> Without going into phantom power for now and sticking with PIP/MD/23,
> BOTH self noise and sensitivity have to be quite good for sound files
> with workable levels of noise.
>
> A test placing all the PIP mics we know of head to head woud be very
> interesting. Perhaps thinking about the goal of low noise field
> recordings as the result of three factors, there could be some other
> mic and pre amp options that we're overlooking. For example, if a
> test shows that the Felmicamps FEL 3.5 mic level booster can attain
> higher output without introducing as much noise as the MD mic pre,
> there might be other devices or even DIY projects that one could use
> for higher quality on a budget.
>
> The next step would be phantom mics for MD line or optical in. Many
> of the gear discussions I have with students and enthusiasts start
> with, "I want to make quality field recordings but I only have $XXX
> to spend,.."
To which part of the answer is that they will be limited in what they
record and they should understand those limitations. It's easy to get
too focused on this price issue and end up with a body of information
that's very incomplete. Even your students should know all the options,
including those that they cannot afford at the time. And know why folks
will spend the money. That's how they can make informed choices and long
term equipment plans that make sense.
The usual way it's set in my experience is that beginners want their
first recording to be as good as the high quality commercial CD's they
have listened to. It takes both experience and good equipment to do
that. Not even if they can afford the high end equipment will they be
instant experts. Whatever equipment you have requires lots of field
experience with it to get the most out of it.
Too much emphasis has been placed on specs and lab tests lately. That's
ok for sorting out which mic you will put your money on, but then all
those specs are no longer the issue. You have barely got started. Your
ability to use the mic is the issue. Only after you have recorded for
considerable time with a mic will you learn what it really can do.
In my recent camera purchase, in reading reviews, I would read lots of
customer reviews where someone could compare dozens of lenses and
cameras they had "used", and had only been in photography a couple
years. They had never used any of it for more than a few weeks before
chasing the specs of some new equipment. Some had, in a couple years,
bought complete Nikon, Canon and Minolta 35mm SLR systems, only using
each briefly before selling and moving on. You just cannot buy being a
expert photographer, and you cannot buy being a expert recordist. I've
spent over 50 years doing photography, and really feel still like a
beginner. So much to learn by doing.
>>Unless you are comparing large sensitivity differences between
>>two mics. Comparing the Shure against the MKH the story is different.
>
>
> There is also significant difference in mic sensitivity going lower.
> I'm pretty sure the NT-4's sensitvity of 12 mv/Pa is much higher
> than the ECM-44's, 77's, Crown PZM's the Crown SASS-- this list is
> quite long.
Before getting too demanding on sensitivity, it's well worth thinking
what it used to be. I have a CD of frogcalls that were recorded in the
50's with, in at least some of it, a spring wound tape recorder and the
old dynamic mics (or maybe worse). They are excellent. We are spoiled
and lack talent in using marginal equipment. Those folks really knew
what they were doing and understood their equipment. They were using
equipment that all your list easily beats.
Back to photography, I can use and get good photos from cameras that are
fully manual, not even a exposure meter in them. (I can even do it with
no lens) I do own and use the latest camera, but I would not have bought
it if it could not do fully manual. The auto stuff cannot do everything
I can do as a experienced photographer. I could probably record frogs
with a wind up recorder and a dynamic mic. If I could find the recorder
I'd probably try it. Always challenge yourself to get the best out of
any piece of equipment. Go out and get good recordings with a old
dynamic mic and you will gain a new perspective.
>>Do not get to thinking all calls recorded were loud. When you factor in
>>distance this is not necessarily so. I record barking treefrogs from
>>great distances sometimes, for example. Greatest was over a mile. By ear
>>it's just a pulse in the quiet background noise that alerts me, the
>>telinga does better than my ears, but it's still imbedded in the
>>background and often the self noise. Many times I can't get closer,
>>though I do try.
>
>
> Absolutely. Noise becomes a factor surprisingly quickly when I try to
> record lower energy natural events at a distance. By "low energy" I
> mean with open spaces where several species/events are sharing the
> space-- not thunderstorms, geese, peepers,..
Actually, the frogs and thunder stuff I want to record will require a
pretty good ambiance mic, for between the thunder. It's the contrast
that's what I'm looking for.
If you think peepers are bad, come down here and meet a bird-voiced
treefrog. They call from about head height, and are not bashful about
calling within inches of your head, straight into your ear. Even though
you did not know they were there. That's really painful! After a while
you can hear again, though. Peepers at least shut up if you are close.
Walt
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