In article , Johan Helsingius
wrote:
On 21-01-17 23:03, Woody wrote:
mp3 works OK provided the data rate is high enough. For most people
192K - or preferably 256K or 320K - is difficult to tell from an
original (classical or jazz) CD
Indeed. I would like to challenge anyone dismissing mp3 to a blind
listening test of well-processed mp3 at 256K. You would have to be very
well trained to spot the difference with typical music material.
Some years ago the Concertgebouw and Hatink released some 'free' high-rate
mp3 versions of their recordings. In general, these sounded pretty good to
me. The only defect I noticed was that an exceptionally quiet section of
one item was a little 'ragged'. I suspect due to some of encoder 'judgment
rules' deciding to discard components as being 'inaudible' which weren't
actually going to be masked at such low overall levels.
I once did a blind listening test on an audiophile forum to see if
people could hear a difference between "hi-res" and CD. As an outlier
test, I threw in a 256K mp3 file (decoded to FLAC, so people couldn't
tell from the file format what it was). The mp3 file came out as the
second most preferred of all 9 alternatives - the "winner" was the
16/44.1 file that I had increased the volume by 1 dB on...
IIRC There was a paper in the JAES some years ago that did some tests and
established that both members of the public and audio engineers could
detect mp3 artifacts provided the rates were low enough. But the main
interesting point in the paper was that the engineers detected the
artifacts as being such. They had the experience to know what things would
sound like *without* artifacts, and the nature of the artifacts to be
expected. The general public, however, simply tended to 'like' the 'sound',
and tended to prefer the modest/low rate mp3 to a clean version. Possibly a
matter of habituation.
Jim
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