On 29/05/2010, at 2:49 PM, Rob Danielson wrote:
>
> Hi Paul--
>> 11K and 20 beats/second seems distinct enough for audio engineers to
>> recognize. I found one other file combining the DR680 and a 3032
>> that appears to be recorded at another time. Its the one labeled
>> "Boundary Array." The other file in the folder is the same
>> 3203->DR680 clip that you found the noise in.
>> http://tinyurl.com/2w4dqoj [2mb download] Rob D.
The Boundary array recording doesn't have the ticking but the clip you used in
the comparison does, so obviously it was an environmental sound.
I've put together a file comparing indoor and outdoor recordings with the
3032's which is perhaps a little unfair. I taken a chunk of a recording I'd
made at Gundabooka National Park in predawn. From memory the gain was set at
about "9" on the super mod hdp2, which with the +6dB gain mod roughly equates
to 10 on a standard version. The hiss above 1khz seems to be fairly closely
matched.
The first 8 seconds is DR680/3032, followed by 12 seconds of SuperMod HDP2/3032
recording predawn still, then a short segment of a 4wd starting up back at
camp. I've checked on google maps and this was 1.6km/1mile away as the crow
flies.
http://demo.mactrix.com.au/dr680/Indoor_Outdoor_3032.wav [5.5mb]
Some of the quieter portions of the Gundabooka recording are -70dBFS
(a-weighted) and as gain at "9" is in the region of 44-46dB this would
translate to a mic output of -114 to -116dBU(a-weighted). Given that the output
for a mic with the sensitivity of 19.9mV/Pa (AT3032) in a sound field of
10dBSPL would be -116dBu(a-weighted) this should be pretty revealing of mic
performance.
cheers
Paul
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