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Re: Only a question

Subject: Re: Only a question
From: Dave <>
Date: Mon, 19 Jul 2004 07:58:24 -0700
On Sun, Jul 18, 2004 at 12:41:31PM -0400, Walter Knapp wrote:

[snip]

> Now, remember that DC offset? Well, it's also a nice way to introduce
> extra noise in a recording. Digital equipment is designed for signals
> that are symmetric around the zero line, and will produce noise from the=

> DC offset. It's why good sound editors have the ability to recalculate
> the samples to remove the offset.

I'm not sure I understand why this would be the case.

[snip]

> And, if you get closer, lower the gain appropriately to avoid clipping.
> It is actually the point of getting closer, to lower the gain so less of=

> the background noise is picked up. It's not a argument against ATRAC
> that you can force a minidisc to clip, you can force any digital
> recorder to clip. It has a long history in anti-minidisc, it's Cornell's=

> main argument to this day. And is as wrong from them as here.

I can't find the URL this morning, but I recently read a document of theirs=

on field recording equipment, and the argument in that article was that
ATRAC (and presumably mp3 and other lossy encoding) was designed around
*human* perceptual shortcuts.  For example, they claim, if two tones close=

in frequency are present but one is significantly louder than the other,
we won't percieve the softer tone and ATRAC exploits this phenomenon and
drops the tone of lower amplitude.  But if other species can resolve two
tones where we cannot, they may be likely to produce calls with that
feature and any resulting ATRAC recording will not reveal that fact.
However, the article contained no citations or references to support
that claim.





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