DAN DUGAN:
> >Recording with 65dB SPL peaking at -5dBFS (and averaging around
>>-15dBFS) brings the mic noise well above the floor of 16-bit
>>recording. For the last several years I've recorded a wide variety of
>>soundscapes with this level, which is what I get with 183s into a
>>Sharp MD at MIC L 17. I found I had to drop my level 6dB (MIC L 14)
>>to cover the crowded parts of the park. I can't recall any natural
>>sounds except thunder I've had to turn down for, and some wind
>>situations where the sound per se wasn't that loud but I wanted to
>>keep the wind noise in the mics below clipping.
ROB DANIELSON:
> For relative ambient levels above the noise floor this should work
>okay. Again, I was thinking you were going to study the
>ambience/influences at a distance You may go down to just few bits
>resolution if its a really quiet setting. Maybe these quiet settings
>are no longer there to study.
Of course quieter sounds are recorded with fewer bits, but that only
matters when you intend to gain-up the recording -a lot-. I recorded
water dripping in Golden Dome Cave at this level, and the mic hiss
was the dominant sound (along with the drips). Saturday night it was
very quiet in Muir Woods, and at locations away from a creek, the mic
hiss was the noise floor, with plenty of room below that to the
16-bit noise floor.
If 65dB SPL is -15dBFS (VU averaging), 20dB SPL is -60dBFS. I rest my case.
><snip>
>>
> >The session length was developed after experience with attended
>>logging. It's about as long as a volunteer can sit still. I've done
>>forty-minute hand-held takes, but I'm a fanatic!
>
>If I specify 15 mins, I get 6-8 mins of non-jostled, fixed level, recordin=
g.
>In similar exercises I've given, it takes about 30 minutes to take in
>the setting's distinguishing features and make coherent notes. My
>thought is: may as well record while writing. Standing silently with
>a body mount is very demanding for any length of time. Rob D.
I've found that writing pencil notes or writing Graffiti on a Palm is
quite audible on my body-worn outfit. But I've also found that I can
annotate with the Soundscape program by touching the on-screen
buttons lightly enough that I don't hear it.
-Dan Dugan
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