Quote:
Originally Posted by W9TR
...The FM hybrid digital/analog mode offers up to 150 kbit/s of lossy data. The pure digital modes use up to 300 kbit/s bitrate. So basically equivalent to 320 kbp/s mp3.
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At the risk of opening a can of worms here, I'll report results of
a little Web research (you know the old saw...). The upshot seems to be that the HD codec (HDC) is far superior to MP3 (per bit rate) and makes better use of psychoacoustic principles (recall Ray Dolby's old work on tape recording) to preserve the subjectively important aspects of many sounds at reduced bit rate.
If interested, take a look at the two PDFs attached. (I found these readily with a Google search on "psychoacoustics.") One is a brief article that (interestingly, I thought) outlines some of the techniques behind modern, "perceptually accurate" codecs. The longer is a chapter from a book (I admit I haven't read this yet -- tonight...) that introduces psychoacoustics.
I'm not saying that any of this makes HD FM radio OK -- I still haven't heard it on an audiophile system! -- just that it shouldn't be written off with bit-rate comparisons alone. -- Clark2