(idm) two types of compression

From BigKumquat
Sent Mon, Sep 6th 1999, 17:09

<< I believe MP3 is wonderful for short samples (altough I prefer real
 audio in this respect for being even smaller), and maybe for radio pop
 which is usually compressed as hell anyway, but I wouldn´t bother
 listening to a whole album in that format. >>

I believe that the compression applied to radio pop is a different kind of 
compression than computer file compression.  Pop radio stations use audio 
processors called "compressors" to squeeze the dynamic range of the signal - 
the soft passages become louder, the louder passages becomer softer - this 
allows the entire signal to be cranked to max loudness as the overall dynamic 
range has been condensed.

This is why your local Top 40 dance-pop station sounds loud and strident as 
you turn the dial, whereas classical and jazz stations will sound softer 
(they use less compression, as excessive use would muck up the dynamic range 
that is considered more critical in those styles of music).

This is not the same as digital file compression (like in mp3), used to make 
files smaller so thay can squeeze through modems...confusing, innit?  Can I 
request some back-up?

- Fred