Re: CD quality!?!?
192!?!?
You are not comparing like-with-like.
CD delivers uncompressed (in the data-reducing sense) audio. Essentially a WAV file. Pretty much all other formats compress the audio in some way, from lossless compression such as FLAC, which can usually achieve somewhere around 4:1 reduction in data, to lossy formats such as the MPEG audio used by DAB which can achieve a lot more, and can be "tuned" to trade off file size / bitrate against "quality".
In proper A/B/X tests, most "normal" people fail to spot the difference between uncompressed audio and compressed audio at somewhere between 160kbps and 192kbps for MPEG II and between 128kbps and 160kbps for MP3. Note that the BBC is now streaming radio using AAC, which is more efficient and "transparent" than either of those, and is doing so at 320kbps.
Musically-trained or sound-engineering-trained people (and perhaps some "golden ears") need slightly higher bitrates for MPEG II and 3, but only slightly. Realistically, no-one can tell the difference between 320kbps AAC and the original audio.
And the golden-eared brigade often kid themselves that they can hear the difference. We had a commercial director at the radio station who claimed to be able to tell the difference between 7½ips tape and 15ips tape, regularly "cleared his sinuses" by sniffing marker pens and took massive doses of vitamin C, but was perfectly happy to take submissions "down the line" using ISDN and a Musicam codec. It was new digital technology so it must be at least as good as the high speed tape.
Just in case you aren't aware, Musicam is a forerunner of MPEG layer II audio (as used in DAB) and ISDN2e has a fixed bitrate of 128kbps (2x 64kbps B channels).
M.
Biting the hand that feeds IT
