There are two kinds of codecs....destructive and (you might figure) non-destructive.

...WAV files are encoded with a non-destructive codecs...basically a 1-for-1 ratio of
bits to the waveform's voltage at the instant of sampling. The digital encoding for
NPR is, at most, companded, but this, like Dolby, can be undone....thus,
non-destructive encoding.

MP3s and methods like IBOC or, from what I've heard, Canadian DAB radio, have
encoding artifacts due to the effort used to eliminate redundant (and I guess the use
of that word is a judgement call, considering what IBOC concludes is redundant) leave
out too much, and thus when the encoded audio is reconstituted, it's missing stuff.
Sortof like freeze-dried ice cream.

And from what I know about the one production audio system, Dalet, this
implementation uses .wav files for storage. So it's about as good as the source, and
thus quite suitable for air. Even these jukeboxes you speak of use a codecs which
result in larger files than MP3s at the same sample rate, but the audio's quite
unaffected by the process. MP3s and other internet and broadcast streaming methods
need to cut down the data rate to levels that can't possibly allow true high fidelity
or even a facsimile of it.
--
For direct replies, take out the contents between the hyphens. -Really!-



"R J Carpenter" wrote in message
...

"Rich Wood" wrote in message
...

I have both Sirius and XM. I agree that the quality depends on the
streams. Classical and Jazz seem to be the highest quality. For analog
I listen to WFCR, Amherst, MA. It's NPR, Classical and Jazz. Very
lightly processed.

And how does NPR get to them? Isn't there a little bird up there chirping
digits to all the NPR affiliates?

I presume they do their music locally from CDs - but haven't the CDs been
compressed onto some automation system's hard disk...?

Bob C.