|
|
|
|
Why DBTs in audio do not deliver (was: Finally ... The Furutech CD-do-something)
(S888Wheel) wrote in message news:WMLNa.16609$I8.10056@rwcrnsc53...
I said I have never seen any scientifically valid empirical evidence on the
matter.You sent six articles only two of which had the raw data I was asking
about.The two that had raw data had not been published in a peer reviewed
scientific journal so they do not qualify as scientifically valid.
Huh? You seem not to understand the purpose of peer review. It does
not determine and is not the arbiter of "scientific validity." For
that matter, neither are you, though you seem to be claiming that role
here.
snip
What I find interesting is the best *evidence* you sent me on the matter was
IMO inconclusive. Some of the evidence in the Clark article suggested that
perhaps some people can hear differences and that some amps tested sounded
different to other amps tested. So how do you deal with that? Do you
acknowledge the test was inconclusive which is what I see or do you claim the
test gives us scientifically valid empirical evidence upon which we can draw
definitive conclusions?
Let's remember that ALL negative ABX results are inconclusive. That
doesn't mean they can't tell us anything.
snip
Wrong.In the Dave Clark test listener #2 got 30/48 correct with a statistical
relaibility of hearing a difference of 94% Listener #6 got 26/48 with a
statistical probablity of 84% chance of hearing differences. Listener #15 got
15/21 correct with an 81% chance of hearing a difference. Given the fact that
no tests were done to measure listener's hearing acuity and no tests were done
to varify test sensitivty to known barely aduible differences one cannot
conclude anything other than those listeners may have heard differences. Bell
curves have no meaning without data on the listener's hearing acuity. The
logicqal thing would have ben to do follow up tests on those listeners to see
if it was just a fluctuation that fits within the predicted bell curve or if
they really could hear differences as the results suggest. Hence there is no
conclusive evidence from this test that as you say"no single listener was able
to reliably identify amps under blind conditions.
I don't recall this article, but this conclusion seems to be well
supported by the data you cite. If the best performance of the group
wasn't statistically significant at a 95% confidence level, then it's
perfectly reasonable to say that no listener was able to identify the
amps in the test. (Note: Saying they couldn't is not the same as
saying they can't. As I noted above, we can never say definitively
that they can't; we can only surmise from their--and everybody
else's--inability to do so.)
Further more many different
amps were used in this test. If some do sound the same and some do sound
different this will have an affect on everyone's score and the bell curve.For
example a Counterpoint amp was compared to an NAD amp and the results of 30/48
correct answers with a probablity of 94% that a difference was heard. Yet no
follow up was done on this comparison.
Yeah, that's close enough that it might be worth someone's while to
redo the test. But the original researcher is under no obligation to
second-guess his own work. People who doubt that result, however, have
been free to try to replicate it for a couple of decades, I think.
That's how science works, my friend. You can't just stamp your foot
and say, "I don't find this conclusive!" You have to come up with a
new result. That nobody--nobody!--has come up with the slightest bit
of real evidence to cast doubt on that conclusion in all this time is,
while not conclusive, certainly revealing.
bob
|