18 Jul
2007
18 Jul
'07
4:56 a.m.
On 18 July 2007 at 16:31, "Stuart Allie" <Stuart.Allie(a)hydro.com.au>
wrote:
That would have been soooooooo much more useful if you
had done your
listening as a double-blind test.
I still have the DVD-A.
That is, if you had listened to the
tracks in a random order and then compared your listening experience to
the track formats after the fact.
I suppose we could bring in another party and do just what you say.
As it is, you could have experienced
a major case of "confirmation bias". You were expecting the tracks to
sound better, and that's exactly what you heard.
It's hard for me as the subject to say for sure, but I don't think I
had much bias. I had a lot of curiosity, not ever hearing the higher
resolutions before.
I don't doubt that
there *was* an audible difference between, say, the mp3 and the 16/44.1
track, but by not doing a double blind test, your results really aren't
useful. Shame about that.
In my message I gave the qualitative statements. There were some
objective measures as well. For instance, coming back from 24/192
land into MP3 land, the piano had a distinctive sound of a flanger on
it, and I'd presume it's artifacts from compressing to MP3. Between
16/44.1 and 24/96 details like the rustle of the drummers brushes on
the snare became apparent, as did the sounds of customers eating at
tables. Going from 24/96 to 24/192 the spacial perception improved,
but the timbre of the instruments didn't change much, if at all. At
24/192 more details of customer movements, things like putting on a
coat, became more identifiable. For the string quartet, bow noises
showed up at 24/96, and traffic outside showed up at 24/something.
When we discovered things like this, we went back down the quality
chain to see where the line of demarcation was between being able to
hear a feature or not being able to hear it. That's still not what
you were after, but it's a bit more objective than my earlier writing.
I'd love to get hold of that disc and have
the equipment to listen to it properly.
I got mine for free from Minnetonka. You might write for one; that's
what I did.
From my reading over the last couple of years what
I've learned is that
the evidence says that:
- 24 bit sounds better than 16 bit at the same sampling frequency
because of increased dynamic range
I've read the same, and it's easy to see why. Especially if music is
going to be compressed to 16-bit CDs, then starting with greater than
16 bits seems like a must, or that 16-bit CD will be more like 12-bit
sound (with the number of effective bits being strongly influenced by
the amount & type of compression).
- 96kHz sounds better than 48/44.1kHZ only when the
processing of the
digital data has introduced aliasing and other artefacts related to the
sampling frequency. So 96kHz tracks often *can* sound better than
48kHz, but only because of poor processing somewhere along the way.
Don't forget that the whole signal path up to the A/D converter needs
to be clean (free from noise & distortion as much as possible) or
whatever "dirt" that exists in the potential bandwidth added by the
sample rate will be captured, whereas less would be captured at
44.1kHz.
- 192kHz is totally unnecessary.
I don't know enough to comment on that.
Hope that helps somewhat. Check out Bob Katz's
web site and book
"Mastering Audio" for more that you could ever possibly want to know
about this stuff :)
I'll add it to my list. Thanks....
--
Kevin