Re: [LAU] newbie to Linux audio

On 18 July 2007 at 16:31, "Stuart Allie" <Stuart.Allie@email-addr-hidden> 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
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