On Wed, 6 Mar 2013 23:14:47 +0000
"Russell L. Harris" <rlharris@broadcaster.org> wrote:
> On a broadcast-grade CD deck with high-resolution bar-graph meter with
> over-range indicator, the playback sounds clean and no over-range
> distortion ("spattering") is obvious.
>
> However, when the SPDIF output from a playback deck is connected to
> the SPDIF input of a broadcast-grade digital recorder, the over-range
> excursions (about once per minute) become very obvious -- something
> like the sound of a cymbal.
>
> The audiobook consists of 8 CDs and cost about $30; the brand is
> Tantor.
>
> One work-around is to play on an analogue CD machine and record on a
> recorder with analogue outputs. It occurs to me that I could use an
> editor such as Audacity to reduce the signal amplitude; but I do not
> know whether that approach would give results which are
> sonically-pleasing.
You clearly know one heck of a lot more about audio than I do, but if
you do want to reduce the amplitude of the entire audiobook, I think
the easiest way to do this is with 'sox'. It wouldn't be hard to write
a quick script to slightly reduce the amplitude of every track (ripped
to .wav first perhaps with cdparanoia). In fact, when I rip audiobooks,
I usually use sox to convert every track to mono and 22050hz, which
isn't hard with a little bash.
Good luck!
> Inasmuch as the over-range splattering is not noticeable except when
> listening to a direct digital copy, I conclude that the original
> recording may have been normalized to eliminate all headroom. Could
> this be a ploy intended to discourage duplication? or could it be (I
> hesitate to suggest) due to ignorance on the part of the engineer?
>
> I have read that not a few personal MP3/WAV players go berserk
> whenever peaks reach nearly to full-scale, so I would expect any
> engineer involved in the production of an audiobook would be aware of
> the need to leave ample headroom.
The evil ploy sounds more plausible to me than I think it does to you.
Then again, I'm cynical.
--
Aubrey
"There are two types of people in the world: those who
can extrapolate from incomplete data."
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