[vorbis-dev] Can compressed music sound better than uncompressed?

[Marshall Eubanks]

Lourens Veen wrote:

> Robert Voigt wrote:
> >
> > I quote from "Principles of Digital Audio" by Ken C. Pohlmann:
> >
> > "Because perceptual coders tailor the coded signal to the ear's acuity, they
> > similarly tailor the required response of the playback system itself. Live
> > music does not pass through amplifiers and loudspeakers, it goes directly to
> > the ear. But recorded music must pass through the playback signal chain. Much
> > of the original signal present in a live recording merely degrades the
> > playback system's ability to reproduce the audible signal. Because a
> > perceptual coder removes inaudible signal content, the playback system's
> > ability to convey audible music logically should improve. In short, a
> > perceptual coder more properly codes an audio signal for passage through an
> > audio system."
> >
> > Is this bullshit or an interesting thought?
>
> Interesting thought I think. It's important to remember that
> uncompressed does not mean perfect quality. According to the Shannons
> sampling theorem any frequencies smaller than 0.5*samplerate (the
> Nyquist frequency) are encoded in the signal, higher frequencies are cut
> off. Also, samples are quantized representations of the original signal,
> and the dynamic range is limited. If we'd send the data compressed, but
> at the same data rate, we'd certainly get better quality because the
> available bandwidth is allocated to things you can hear, rather than a
> simple limited linearly-described portion of the sound.
>
> But I'm not a real expert :).
>
> Lourens

I can think of special cases where they would.

Suppose that there was a lot of noise up at 21 kHz. You can't hear it, but
it could be aliased into audible frequencies, or even saturate the system and lead
to dynamic range loss or in a bad case (ugh!) clipping or other performance degradation.

So, in that case, the compressed signal could sound better, conceivably much better.

In general, though, I think that "as good as before" is the best you can expect.

On a different slant, sometimes (not often) heavily compressed MP3
files have a cool robotic sound to them. I can easily see a EDM musician
using a compression box along with turntables, etc., to modify
the sampled sound, even in a live performance.


--
                                 Regards
                                 Marshall Eubanks

T.M. Eubanks
Multicast Technologies, Inc
10301 Democracy Lane, Suite 410
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Phone : 703-293-9624
Fax     : 703-293-9609
e-mail : tme at multicasttech.com
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