At 15:37 2005-08-30, you wrote:
>Thanks Klas,
> >The mic's are made for indoor studio work and cannot!! be reliable
> >under cold / humid circumstances. (I still wanted to try them, though, a=
s
> >they are new and untested)
> The potential of quality recording with one of these budget mics, albe=
it
>with the weather conditions being ideal, is consoling to me.
It's not only the "budget" label which make them unreliable. It is the
principal design and nature laws.
To get internal noise down to -8 db(A) figures (or lower) means a few basic=
factors:
1 / big and flexible membrane,
2 / very small gap between membrane and electrode and
3 / high polarizing voltage.
Neither one of these harmonize with humidity. R=F6de etc have proved that i=
t
is possible to make ultra low noise mic's at a low price, but so far every=
mic manufacturer have failed in making a design which also works in
humidity / low temperatures.
Consider that a R=F6de membrane is one inch in diameter. That is quite big!=
And it is very flexible. Then consider that the distance between this one
inch membrane and the electrode is only some 5 thousands of a millimeter!
When conditions change, humidity and temperature, the membrane may slack
and get sucked against the electrode by the polarizing voltage. Both the
R=F6de and CAD try to lower this risk by using a center screw, holding out=
the membrane, but it doesn't help.
Or the smallest little dust between the membrane and the electrode gets
humid and starts leaking polarizing voltage, causing a strong low frequent=
noise.
On top of that, the input impedance of the mic amp is in the 500 megohm
region!!!
My friend J=F6rgen in Stockholm makes smaller capsules running on low
polarizing voltage, still Ultra low noise, 8 db(A) and lower. Knock wood,
still they work, but are no budget mic's and he makes them by hand in a
very small number with extreme!! quality control! I would say they are the=
best mic's available, but I would not guarantee the function when cold
and/or humid.
Bruel and Kjaer make true condensor mic's which work most of the time. But=
they never claim ultra low noise figures.
> > There is so much
> >lying about this and all manufacturers have to follow.
> Hmmm... No standards...are the manufacturers spec guidelines ambiguous?=
Do
>we need call the mic police on these guys? ;^)
> I once heard a definition of marketing, that it gives us what we want t=
o
>hear and leaves out the rest.
That's true. But it is worse than that. Measuring is a flexible term and
the figures you get is often a result of how you measure. I trust
Bruel&Kjaer and Sennheiser, but nowadays I even hesitate about Neumann figu=
res.
They just have to present the figures they do, or die.
Guess what they choose??
Klas.
> Best,
> Mark R.
>
> >
>
>
>[Non-text portions of this message have been removed]
>
>
>
>
>"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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