At 12:28 AM -0400 9/8/08, Walter Knapp wrote:
>Posted by: "Rob Danielson"
>>
>> Even if one manages to
>> completely remove them, as Walt points out, the effective noise
>> performance in the field can vary because some natural locations have
>> high frequencies that will mask some or all of the self-noise.
>
>I don't believe that's what I said at all. What I'm saying is that
>indoor noise fields are not representative of outdoor ones. Certainly
>not so for mic testing purposes.
>
>Note that high frequencies attenuate with distance quite rapidly. They
>are rarely a problem outdoors nature recording as a result. It's the
>low frequencies that can come from a very long ways away. So, I'd have
>strong doubts about any masking effects.
>
>Walt
Hi Walt--
The kinds of sounds with mic self-noise masking abilities that I'm
thinking of include wind in the grass and leaves, several types of
precipitation and insects. The insect chorus here tonight is
producing several, sustained, high-frequency bands between 4K and 12K
Hz. Those around 4KHz are as loud as the lowest frequency background
sounds (both reaching -40dB on 96dBFS). The bands around 8Khz and
10KHz are substantially softer but are still louder than the "hiss"
produced by the self-noise of my mics. Rob D.
--
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