At 1:29 PM -0400 9/9/06, Walter Knapp wrote:
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>I operate with 15dB on average for headroom,
I've been monitoring my results in northern woodlands in this regard
pretty carefully and I agree. If I set the background ambience at
-15dB, its very rare for an natural event to over-modulate. I set
both the side and the mid at this level.*
Even with this limited dynamic range and increased headroom of
digital media, I still regard saturation pretty carefully when
recording in Hi-SP mode because sufficient** bit depth seems like it
helps ATRAC efficiency. When the ATRAC original is "thin," I notice
that my EQ plug is less responsive and there are more spots along the
spectrum where frequencies seem under-represented. Perhaps the
slight degradation stems from shifts in ATRAC Hz emphasis with
content. At what level the degrading sets in, I could not say. The
-15dB background calibration method is pretty reliable for me, but
my "safe" level could be higher than some recordists want to risk.
With 16 bit originals, I EQ and convert them to 24 bit sub-masters in
one step (saving the settings should I question my judgement later
on). Its during this stage that I tend to notice the differences in
outcomes. After I get through this demanding school year and
relocate in LaFarge, such tests will be much easier to do.
*At night, unless I'm close to a pond or other active spot, I'm at
full pre gain anyway and the natural ambience is well under -15dB
unless its windy, raining etc
.
** Assuming a modest dynamic range of 15-25dB, shouldn't we be able
to get adequate saturation and headroom with digital media?
>so that's what my mid will be set at (and for some sites it might be
>as low as 25dB or more, it's
>based on my estimate of the probability of a louder call). I've found
>the side to balance right with as much as 30dB below the mid upon
>occasion, depending on the site, may have used even more at times, can't
>remember just now. That's a total possible setting on the side under
>your system of 45dB down. That is a lot, particularly as I do still
>record with a 16bit system and don't expect that to change anytime soon.
>
>Wasn't Rob giving us a talking to a little while back about how much we
>lost recording that low? Particularly in 16bit. About how the lower half
>of the range did not resolve as well as the upper half? Maybe should
>resolve that issue before going down there as a standard practice? If we
>record in the bottom 60dB of the dynamic range of a digital recorder
>will the recording be as good as if we did so in the top 60dB?
Isn't bit distribution/resolution linear up and down the scale? Rob D.
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>Walt
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