Another effect of humidity in a "true" condensor mic is that the voltage
between the electrode and the membrane will make the membrane stick to the=
electrode until you switch the mic off. Then it might work again until a
little wind pushes the membrane against the electrode again.
I don't know how big the R=F6de membrane is, nor do I know the distance
between the membrane and the electrode or the polarizing voltage.
The bigger membrane,
the thinner membrane,
the smaller distance between membrane and electrode,
the higher the polarizing voltage.....
- the bigger risk that this will happen.
Klas.
At 19:01 2005-02-17, you wrote:
>From: "Ryan" <>
>
> >
> >
> > I'm sitting in an internet cafe in the Khao Sok rainforest in Thailand =
and
> > I'm disapointed with my inability to record sounds of the crickets and
> > other night time sounds without getting pre-amp noise from the
> > microphone.
> >
> > My equipment:
> > Rode NT-4
> > Sony NH900 MD recorder
> > Mic Recording level set at 24
> >
> > How do the people who create nature cd's that are sold in stores do it?
>
>On average they are using better equipment. It's possible to produce CD
>quality recordings with your level of equipment, but it's not near as
>easy. Mostly you have to get as close as possible to keep the gain down.
>
>Nightime sounds are often very low level, a challenge to record with any
>equipment. Many of the small insect sounds here are barely audible, and
>require work to record well. And very low noise equipment.
>
>Keep recording, and pay attention to what works and what does not. With
>time you will find that your recordings improve. Nature recording is not
>something you can be a instant expert producing CD's for publication. It
>takes time to gain the experience to get the best out of your equipment.
>
> > Is the pre-amp noise taken out in post production with software (i.e.
> > adobe audition?)
>
>Do not count on being able to filter out much. Particularily in ambient
>recordings it's hard to hide the filtering. Try always to get recordings
>that need little or no filtering.
>
> > Also, I noticed I was getting some sounds from my mic after listening
> > back to what I recorded earlier. the sounds were as if I was moving the
> > mic around or fiddling with the cable - which I wasn't. Could this be t=
he
> > result of humidity? If not, what effect does humidity have on mics? It=
is
> > the dry season here right now, so i figured humidity is low however I
> > can't be certain.
>
>The NT-4 is known for being very sensitive to handling noise. Movements
>you hardly notice can cause the problems. Try mounting it on something,
>preferably with a suspension, and then setting recorder, cable and all
>down where there is no cable swing and see if that goes away. If so,
>it's handling noise. It's one of those things that you develop habits
>with experience to avoid. If you are not using a suspension for the NT-4
>I'd suggest you may need one. You can hand build these if necessary.
>
>It's also possible it's humidity, the NT-4 is somewhat sensitive to
>this. What generally happens with humidity is the high voltage being
>maintained on the capsule leaks or even arcs off. This translates into
>sound, or if bad enough the capsule cannot work at all and goes silent.
>Or they can just get noisier and noisier until you can't record.
>
>One of the reasons MKH mics are so good at handling humidity is the RF
>mic system they use has a much lower voltage charge on the capsule.
>
>If there was any breeze at all, the sounds you were getting could be
>wind noise. You will have to use a windscreen for that, and even then
>there are limits as to how strong a wind you can record in.
>
>Walt
>
>
>
>
>
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links
>
>
>
>
Telinga Microphones, Botarbo,
S-748 96 Tobo, Sweden.
Phone & fax int + 295 310 01
email:
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