Look at MLSSA at googles, or I presume you already know about it.
I think pulses are the only way, and I think one must make at least 10
measurement of the same and compare them, to test reliability. Even
unnoticeable wind movements make unexpected impact on high frequency
distribution.
Klas.
At 09:14 2004-03-02 +0100, you wrote:
>Dan, you wrote,
>
>> Raimund, you wrote,
>>
>> >I will use a sine sweep played through a portable CD player. A sine swe=
ep
>> >would probably better suited because it could be difficult to distingui=
sh
>> >between emitted noise and the ambient/self noise.
>>
>> I dunno, it's harder to interpret, harder to display a sweep. I'd use
>> pink noise turn off the source for part of each setup to get a
>> recording of the ambience. Then you ignore the parts of the response
>> where you don't have 10 dB or better s/n.
>
>Yes, there are various approaches for measuring frequency responses. The
>noise approach is definitely easier to interpret. The sine sweep approach =
would
>require spectrographic analysis. Though it would even be possible to use a
>simple spectrum display for analyzing a short linear sine sweep (as long a=
s the
>spectra are computed from a single sweep and without applying any weightin=
g
>windows as Hamming or something similar).
>
>So, perhaps I will prepare a CD that contains both sine sweeps and short
>noise bursts.
>
>Raimund
>
>--
>GMX ProMail (250 MB Mailbox, 50 FreeSMS, Virenschutz, 2,99 EUR/Monat...)
>jetzt 3 Monate GRATIS + 3x DER SPIEGEL +++ http://www.gmx.net/derspiegel +=
++
>
>
>
>"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
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/naturerecordists/
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
------------------------------------------------------------------------
|