On Monday, December 17, 2012 6:48:54 AM UTC-8, Arny Krueger wrote:
"Audio_Empire" wrote in message
...
On Saturday, December 15, 2012 8:08:32 AM UTC-8, Scott wrote:
My sentiments exactly. I'm convinced that while DBTs work great for drug
tests, tests by food manufacturers about new or altered products, etc.,
I'm not terribly sure that they work for audio equipment because the
waveform that we are "analyzing" with our collective ears is pretty
complex.
Anybody who has seen how certain tightly held but anti-scientific beliefs
are readily deconstructed using the results of bias-controlled listening
tests can see how people who keep on holding onto those beliefs would have
reservations about such a clear source of evidence that disagrees with them.
Well, first of all, Those "beliefs" that are are saddling me with are not "anti-scientific".
There are differences in electronic equipment and I'm convinced that some day there
will be tests that will reveal them. I've been in electronics long enough to know that
you will never uncover a piece of gear's flaws if your suit of measurements keep
measuring the wrong thing. Unfortunately, I don't know (any more than anyone else)
what we would test to account for the differences in modern amps (very small
differences, probably not worth the effort) or DACs (much larger differences). None
of these things are addressed in any test suite I've seen. Yes, we measure frequency
response, IM and harmonic distortion, channel separation, impulse response (in
DACs) perhaps we use an oscilloscope to look at square waves to measure low and
high frequency phase shift, but none of those really address things like the difference
between the imaging ability of two DACs, for instance, Where one of them has a more
three-dimensional image presentation that the other especially since both DACs
measure similar channel separation (which is so high in digital that as to ostensibly
be, for all practical purposes, beyond the limits of the human ear to perceive that
kind of isolation of right and left). Obviously, there is something that we humans
are not measuring.
Quote:
Otherwise for DACs, preamps and amps, there are certainly differences (in
DACs, especially) yet they don't show-up in DBTs and ABX tests.
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On balance we have a world that is full of DACs with better than +/- 0.1 dB
frequency response over the actual audible range and 100 dB dynamic range.
They now show up in $100 music players and $200 5.1 channel AVRs. Where
in fact are the audible differences in those DACs supposed to be coming
from?
That's the puzzlement isn't it? Like I said, if the accepted suite of audio measurements
don't answer the questions, then obviously there is something that we don't measure.
It's the only plausible answer (and don't posture that these differences are imaginary;
the product of listening biases, because they aren't.
Quote:
Granted, with modern, solid-state amps and preamps the differences are
minute (and largely inconsequential), but they do show themselves in
properly set up DBT tests.
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No adequate documentation of the above alleged fact has been seen around
here AFAIK.
I agree. It's a puzzlement. I know that I, and several other audio enthusiasts of
my acquaintance can tell the difference between two amps in a carefully set-up
DBT almost every time. Yet. others in these ad-hoc tests seem to hear no differences,
and their results are essentially random, I.E. a null result. The only thing that I can
come up with is that I have been listening critically to different components for so
long, that I pick-up on audible clues that others simply miss.