On Mon, 11 Feb 2008 16:17:08 -0800, bear wrote
(in article <foqoi402tkd@[EMAIL PROTECTED]
>):
> Arny Krueger wrote:
>> "Greg Wormald" <greg.wormald@[EMAIL PROTECTED]
> wrote in message
>> news:folrst02p34@[EMAIL PROTECTED]
>>
>>> The very set-up of much ABX testing (which is most often
>>> short segments of music quickly switched), cannot test
>>> for what most music lovers are seeking--long term
>>> enjoyment of music listening.
>>
>> This is a false claim that I've heard on and off for about 30 years,
now.
>
> Well Arny, where is the correlation between ABX tests and subjective
> enjoyment?
> Don't think there is any...?
>
> The ABX is intended and designed to merely yield data about audible
> differences
> between two variables - nothing more.
>
> IF it accomplishes that goal is yet not clear and unproven beyond the
> specific
> test that took place. In other words the results of specific ABX tests
can
> not
> be generalized to pertain to every situation. While the results *might*
be
> useful or of general use, it is not an inherent quality of an "ABX"
test.
> The reasons - as have been debated here many times - are multiple.
>
>>
>> In fact people have been doing long term ABX tests for about 30 years.
The
>> origional ABX Comparator product, had special features to allow tests
to
>> survive power outages, in sup****t of long term tests.
>>
>> One of the things that long term ABX tests show is that audiophile
>> mythology
>> about long term testing is just that, audiophile mythology.
>
> No Arny, that is merely your belief and your conclusion.
> It is not fully sup****ted by any factual basis.
>
>>
>>> A goodly number of years
>>> ago I ABX blind tested some interconnects, and then chose
>>> the ones I preferred. Three months later I realised I was
>>> not listening as much or enjoying it at the level I was
>>> previously. I found myself turning the music down or off.
>>> When I went back to my old interconnects my listening
>>> increased to it's previous levels of enjoyment.
>>
>> AFAIK nobody has ever shown that interconnects can be distinguished
>> sonically using any reliable listening test methodology, unless they
were
>> so
>> bad that they cause non-trival frequency response variations. And, if
>> interconnects are so bad that they cause non-trivial frequency response
>> variations, they are by definition, defective.
>
> This would appear to be a true statement.
> But it is not.
> The reason that it is not true is that the "ABX" tests that have been
touted
> as
> providing this information are fraught with unknown variables.
> Let me list a few for the readers:
> - frequency response of the speakers
if you are using the SAME speakers for each component under test, the
frequency response of the speakers is a constant, NOT a variable and
therefore is irrelevant. If you are using different speakers for the ABX
test, then you're doing it wrong by introducing more than one variable
into
the test.
> - distortion vs. power vs. frequency for the speakers
See above.
> - polar response of the speakers vs. frequency
Again irrelevant because the cables/interconnects are feeding the same set
of
speakers.
> - reverberation time vs. frequency of the room
Same room for both components under test, the room becomes irrelevant.
> etc. etc. etc....
>
> EVEN WITH this information, I have yet to read a published ABX test that
> would
> permit someone to precisely duplicate the test. Not enough information
is
> provided.
Not needed. All you need is a system and a way to switch between two
different components carrying the same signal at matched levels. This can
be
done by a ABX switch box or a third party who either switches or not on
command from the listener(s).
>
> Show me *one* that has the requisite information and controls.
It's really very simple. after matching levels and using the same source
material, merely switch between the two units under test and determine if
you
can hear a difference. Listen as long as you like to either or both
contenders and decide whether or not you can tell ANY difference between
them. It's that simple.
>
> Dr. Earl Geddes' research - and he is a hardcore
> academician/scientist/researcher - has shown that absolute values of
> distortion do not translate at all to audibility of distortion.
But that's a different discussion and has nothing whatsoever to do with
blind
or ABX testing.
> So, the sum total of all this is that ABX is a tool that may or may not
yield
> information that is useful. Period.
Well, ABX/Blind testing can really only tell two things: Is there a
difference in the sound between two components (or interconnects or
speaker
cables)? And if there are differences, what are they? It cannot tell
which
is better (assuming that there are differences) as that is a totally
subjective call.
Where this type of testing REALLY falls down is where the differences are
subtle (which they often are) and the listener doesn't have the trained
listening acumen to pick-up on those differences. Since there is no way to
eliminate or even pre-screen for this particular variable, the results are
often going to show that there is no difference, when in reality, the
listener(s) just missed them or really cannot hear them. The results never
work the other way where the unsophisticated listener reliably and
statistically hears differences that aren't there. I'm sure that you can
see
why that's so.
|
