At 18:58 2005-05-14, you wrote:
>--- Klas Strandberg <> wrote:
> > Thanks Dan, I agree and have no other comment.
> >
> > But I could add:
> >
> > Have you ever put a medium class directional
> > microphone on a rotating plate in front of a
> > 10kHz speaker and looked at the linear voltage
> > output for different degrees?? I guess not....
> >
> > Cause if you do, you will find so many peaks and gaps
> > - 40 db and more!! - when turning the mic only a few
> > degrees one or the other direction!
>
>
>Lacking an anechoic chamber, have you ever tried this out in the
>middle of a field? I would suspect that reflections from nearby
>objects might be causing cancellations.
Yes, I am aware of the difference between anechoic chambers / outside and
reflections inside. But such a high frequency (10 kHz) is rather easy to
absorb by fibre wool etc.
I like outdoor measurements! All parabol measurements are done outside, at
a distance of 30 meters. That's why I live as I do, in one of the most
quiet places in mid Sweden. The error is wind "blowing" away the high-freq.
sound! Just a very slight wind, hardly possible to sense, make you loose a
lot of db. So when designing a mic, one has to make many measurements and
see a pattern - "better than before" or "worse than before". Never any
"objective" data.
Klas.
>
>"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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