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Re: 722 vs [was] NT1-A and moisture

Subject: Re: 722 vs [was] NT1-A and moisture
From: Klas Strandberg <>
Date: Tue, 21 Jun 2005 21:37:59 +0200
At 15:55 2005-06-21, you wrote:
>We're getting close to realizing we can't make
>useful generalizations about MD pres and best
>refer to particular mic- preamp combinations when
>making comments or judgements. I can't see what
>there is to gain by generalizing about condenser
>mics in outdoor use.  If was true, why does the
>mkh 30 go out first sometimes?

There is a reason to generalize about 1/ Condensor mic's 2/ electrets and
3/ MKH mics.

Why are condensor mic's more sensitive to humidity?
Answer: The gap between membrane and electrode is very small and not only
that - there is also a polarizing voltage in between.
On top of that: The input impedance of the first transistor is gigaohms and=

one can easily picture what happens when there is condensation at the
circuit board.

2/ Electrets (which also are condensor mic's!) are less sensitive, mainly
because there is no polarizing voltage applied on the membrane.
However, the input impedance problem is the same and one has to carefully
chose a PCboard lacquer  which doesn't absorb humidity.
There are "worst case" scenarios: I tried a new and very fancy lacquer
which was sent to me by a very fancy company. After 24 hours and more, the=

value of a 1g resistor dropped 60% just by breathing at it a number of
times. That lacquer at a mic PCboard would definitely ruin the design.
Output voltage from the mic would drop a lot, but not the inherent noise.

Still, condensor mic's may work very well. But I would never make a
important journey with only one or a pair of condensor mic's, - R=F6de or

3/ MKH line is something else: There is no polarizing voltage, neither is
there an extreme input impedance. Instead, the membrane/electrode
configuration is just a variable resistor which determines the frequency of=

an oscillator. This frequency is, in turn, made into voltage.
Also, the membrane - which faces the air - is the same polarity as ground.
This means that when speaking of risks with condensor mic / electrets, one=

has to exclude the MKH line.

This is important to know for users, and that is why I pointed it out.

Also a MKH will go out. That is another thing.

I looked at a NT1A presentation. I wonder if R=F6de is another one using th=
China 1 inch capsule? The same as in CAD179, for example?
I cannot imagine that they are sitting in Australia, making genuine R=F6de=

mics of that category and selling them for 199 USD.


>I've been using
>NT1-A's in the field for two years now, that
>wouldn't be the case if they were unreliable.
>There are spec sheets on line at Rode. I
>understand that the NT1A and 2A are unusual
>circuits as mics go. The electronics seal is
>decent. You have to keep direct water contact off
>of the capsule. Rob D.
>   =3D =3D =3D =3D =3D =3D
>At 2:38 PM +0200 6/21/05, Klas Strandberg wrote:
> >People - all condensor mic's are unreliable in the wilderness, except th=
> >MKH. It is not a matter of brand, but of construction.
> >With it's RF modulation and membrane connected to ground, the MKH has
> >outstanding reliability.
> >
> >Question: I hear a lot on the list about the perfection of R=F6de mic's.=
.? I
> >don't find them outstanding. I think they perform about the same as a lo=
> >of other mic's. Good, but no sensation...?
> >And even if very carefully made, they must be unreliable in humidity.
> >How high is the polarizing voltage? Anybody know?
> >
> >Klas.
> >
> >At 05:56 2005-06-21, you wrote:
> >>  > <<<<Now we as a group have to talk Rhode into an Omni version of
> >>  > the NT-1a
> >>  > as it clearly is outperforming the mkh line at a lot less
> >>  > money.>>>>>>>>
> >>
> >>Whoa! That's a dangerous statement. Noise floor is only one spec for
> >>a microphone. It's not fair to compare the MKH line to this mic, I
> >>think for a couple of reasons:
> >>
> >>1) The MKH are designed to be rugged, very resistant to humidity,
> >>etc. The NT1A is clearly a studio mic, has anyone actually taken it
> >>out into the field.
> >>
> >>2) How do they 'sound'. I buy Schoeps because in spite of their
> >>higher noise (to the MKH) I think they're the best sounding mics in
> >>the world. I love the imaging I get, and I personally think they
> >>sound better than the MKH (which are great, don't get me wrong). But
> >>the MKH are way better for humid recording, the Schoeps may very well
> >>crap out (although I've never had it happen yet).
> >>
> >>But noise floor alone is no way to decide between mics.
> >>
> >>That being said, I think I'll buy one of these, might make a good
> >>studio mic for recording very quiet sound effects
> >>
> >>Tim
> >>
> >>
> >>"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: 
> >         
> >
> >
> >
> >
> >"Microphones are not ears,
> >Loudspeakers are not birds,
> >A listening room is not nature."
> >Klas Strandberg
> >Yahoo! Groups Links
> >
> >
> >
> >
>Rob Danielson
>Film Department
>University of Wisconsin-Milwaukee
>"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


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