Thanks for the plausible explanation! You're right, my waveform app
shows a clip at two magnification scales but it measures a peak of
94%. I'm hearing three, pronounced, moments of distortion that sound
like chain shaking in the louder, CD player call and two of these,
but softer in the original. As the 2nd half of the file was produced
from the CD player's analog amp/output passing through another A-D, I
guess its hard to tell where the exaggeration is coming from exactly.
The distortion is too wide to address with EQ. Surgical gain
reductions were not very successful either. The harshness of the
undistorted portions are responsive to EQ (e.g. mastering).
The softer call seems great so Rich has a simple work-around. I guess
there could be several reasons the softer call escaped distortion.
Dan, do you think that a lower record gain would have eliminated this
type of distortion or is it likely to be more complicated? Rob D.
= = =
At 6:22 AM -0800 1/10/06, Dan Dugan wrote:
> > > http://home.comcast.net/~richpeet/0659.wav
>
>It may be a type of analog audio distortion called slew rate
>distortion. It affects high-frequency, high-level material, adding a
>lower-frequency rasp to it. The peaks aren't clipped, but the slopes
>are flattened out at an angle, i.e. a sine wave is changed into a
>triangle wave. Easy to hear, hard to see on a complex waveform.
>
>-Dan Dugan
>
--
Rob Danielson
Film Department
University of Wisconsin-Milwaukee
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