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Re: arsclist cylinder frequency range
Date sent: Thu, 17 Jan 2002 10:36:55 -0800
To: ARSCLIST@xxxxxxxxxxxxxxxx
From: David Seubert <seubert@xxxxxxxxxxxxxxxx>
Subject: Re: arsclist cylinder frequency range
Send reply to: ARSCLIST@xxxxxxxxxxxxxxxx
David,
you wrote....
when compressing files using Quicktime that
> the less noise in the source, the better the compression works.
----- in which way better? - we need a terminology here.
Compression is usually loss-less. Data reduction is not.
Physiological data reduction (my, hopefully more precise, term for
"psychoacoustic data reduction") actively removes that which
might be unheard anyway by average humans because of various
types of masking. Subsequent spectral correction may then call for
signal components which are no longer there. "better working
compression" might mean "enables really low data rates" or "does
not sound too artificial", if we are really talking data reduction. At
any rate, trying to apply signal processing to a retrieved data-
reduced signal, in particular where the S/N ratio is low, really
creates trouble.
Given
> the amount of noise in a cylinder, we are going to have to use some
> sort of low pass filter or the compressed files will sound terrible.
----- I do not think that low-pass filtering is a good thing. In the
LINEAR world I would propose using a wide frequency range for
distribution, because low pass filtering is so simple that an end-
user can apply it to his or her own taste. Distributing a low-pass
filtered signal is distributing a mutilated signal. In a data reduced
world I appreciate that there would be a need for a different
compromise.
> We haven't yet decided what frequency the low pass filter should be
> at. When our tests are done, results will be posted on our website.
----- here I would support Joe Salerno's idea that you might put
something semi-manufactured on the net. If the ARSClist is not
suitable for hefty files, then perhaps you could put it on a server,
password "ARSClist".
Kind regards,
George
Preservation Tactics
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