[colug-432] 24-bit Sound Input
dmaxwell at columbus.rr.com
Sun Dec 13 01:02:47 EST 2009
On Sun December 13 2009, vince at planetvince wrote:
> 2. Audacity has a auto level function I've used.
> It looks at the entire file and then adjusts the level to the max with no
> clipping. Possibly this will eliminate the 24/16 bit issue.
That is normalization and it should almost always be the final step of
processing a given bit of audio. It doesn't solve the issue because 16 bit
audio at 44 or 48 kHz is a final destination format at "CD quality". To get
CD quality a given piece must be sampled such that the loudest peak in the
piece is also the loudest sample that it is possible to take but no louder.
In practice, this can't be accomplished. You want that because you want the
widest possible variation between the loudest and softest samples in your
recording. This is called "dynamic range".
That is why I would play a record side a time or three to get as close as I
could before actually recording. If however, I record and edit in 24 bit and
set my levels such that I'm consistently hitting around 75% then I'm assured
that I'm taking advantage of an amount of dynamic range that easily exceeds
that possible in a 16 bit recording. And I wouldn't need to be fiddly about
it. I only have to be consistently using in excess of 16 bits while sampling
the audio. If I normalize that THEN downsample to 16 bit I'll have a
recording that will have both a reasonable filesize and excellent audio
In analog terms, a 24 bit/=>48kHz recording is pretty like using 1-inch audio
tape at a fast speed. If then master that down to an audiocassette, I'm
assured of taking advantage of the maximum a Phillips cassette can offer.
This is why a cassette you used to buy would pretty much always sound better
than dubbing one off your friend's copy.
Normalizing by itself doesn't create information. Dynamic range is one analog
measure of a recording's information content or the ability of your playback
equipment to reproduce it.
Old MacDonald had an agricultural real estate tax abatement.
More information about the colug-432