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  #202   Report Post  
Norman Schwartz
 
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Default Seeing/hearing and sighted/blind tests

"Steven Sullivan" wrote in message
news:KT62c.50154$ko6.396612@attbi_s02...
S888Wheel wrote:
What validation test and results would prove that DBT is not working?
It sounds to me as if this an important piece of information in order
to get this discussion any further.


That is easy. One can insert something that will generate a *known

subtle
audible difference* into the random samples.


What's a *known subtle audible difference* that *hasn't* been determined
by controlled comparison methods?

Any examples you'd care to offer?

Yes. Look at the big differences in the responses of various CD-players to
single frequency test tones and how little difference, if any, can be heard.

  #204   Report Post  
Norman Schwartz
 
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Default Seeing/hearing and sighted/blind tests

"Michael Scarpitti" wrote in message
...
"Norman Schwartz" wrote in message

news:gQK1c.458979$I06.5174464@attbi_s01...


Perhaps I should be asking you a more important and meaningful question:

In
the time it requires to carefully unwire and re-wire two different amps
(avoiding any "shorts") how is it possible to have the exact mental

picture
of their differing sound characteristics.


I repeated the trials several times.

Additionally the amps under test
comparison cannot be called upon to put out anything near that used to

drive
most loudspeakers to any reasonably loud level. So what use is any

headphone
listening test?


Huh? I would be using the selected amp with these headphones. I also
connected them to and listened to the speakers, which showed similar,
but less dramatic differences.


You appear to be suggesting that headphone listening provides a better and
finer test in revealing an amp's characteristic. However in casual
loudspeaker listening an amp might easily be "pushed" ten times harder than
in headphone listening, at which level any Stax headphone would fry. At
those low levels required for headphone listening I don't believe anything
at all is revealed of its sound *or even its* ability to drive a loudspeaker
such as a big 3-4 ohm resistance Maggie needing a hefty amp. A 20 watt
Kenwood receiver could easily deliver more than sufficient juice to drive a
Stax headphone but couldn't get a big Magnepan off the ground. Been there,
done that, more than 30 years ago when the flimsy Stax SRD-7 "Adaptor for
Ear Speaker" first appeared in the marketplace.
  #205   Report Post  
Norman Schwartz
 
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Default Seeing/hearing and sighted/blind tests

"Michael Scarpitti" wrote in message
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Stewart Pinkerton wrote in message

news:KvQ1c.44925$PR3.895219@attbi_s03...

As it happens, a very long time ago, before the scales fell from my
eyes, a group of us actually did try a very carefully controlled
experiment involving 6 CDs from the same batch of pressings of Dave
Brubeck's 'Late Night Brubeck', played through Naim electronics into
Epos ES11 speakers ( the shop demo system of the guy who owned the
record store which naturally had lots of those discs). The 'green
penned' discs sounded exactly the same as the untreated discs -
although a couple of the original batch were rejected because for no
known reason they did not sound the same as the other four.
Scarpitti's claim is extraordinary at best.


The Stax Lambdas allow one to hear things that most transducers do
not. What is 'extraordinary' is their clarity. With these devices, I
can hear the difference on some CD's, with the green-pen treatment.

Can you also hear the effects of demagnetization and Armor All treatment?
Enid Lumley heard effects produced by the position of her kitchen water
faucet.


  #207   Report Post  
Stewart Pinkerton
 
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Default Seeing/hearing and sighted/blind tests

On Fri, 05 Mar 2004 18:10:48 GMT, "Frank O. Hodge"
wrote:

Some
$5000, for telling cables apart? Perhaps five cables, 60 seconds for
each audition (because the differences will be subtle but obvious), 25
permutations, a couple of pots of coffee and associated breaks, and
there's merely a light afternoon's work. All I infer is that I've got
to guess them right, one time only, not that I've got to write a memo or
any such thing.


You have to tell two cables apart and get it right 15 times out of 20,
that's all. Under double-blind conditions, and with the voltage at the
speaker terminals matched to +/- 0.1 dB at 100Hz, 1kHz and 10kHz. No
biggie for any two reasonably normal cables.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

  #208   Report Post  
Stewart Pinkerton
 
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Default Seeing/hearing and sighted/blind tests

On Fri, 05 Mar 2004 18:12:07 GMT, (Michael
Scarpitti) wrote:

Stewart Pinkerton wrote in message news:95L1c.42957$PR3.843082@attbi_s03...


Actually, Occam's Razor suggest that all nominally competent
amplifiers do indeed sound the same.


Question-begging. What is 'competent'? The ones that sound the same?


Essentially, yes. And I know it's a circular argument.

In the light of many decades of psy research which shows that our
perceptions aree very easily fooled, Occam's Razor also suggests that
the simplest explanation for your claims is that the perceived
differences existed only inside your skull. Of course, that may not be
the case for every amplifier, but without a blind test, you'll never
know for sure.


...and just HOW does the perception into which I am thus 'fooled'
unfold itself in such explicit detail, that highs are rolled off on
one amp, transients ring on another, and dynamic compression occurs on
a third? How creative I must be to do this all in my head! And how
consistent I must be to be able to reproduce these 'phenomena'
precisely 4 months later, when after the amp I selected kept blowing
up, and I repeated the auditions! Occam's razor does, in fact, support
my interpretation much more than yours.


Nope, since reinforcement is a very simple concept indeed, and has
been proven many times - by yourself, among others.

The reason is that you must
account for a rather complicated behavior for my mind to 'create', ex
nihilo, 7 distinctly different sounds for 7 different amps, and be
able to re-create these sonic 'signatures' exactly and repeatedly, and
only when the amp in question is being listened to, without confusing
them.


It's easily accounted for, and can easily be explained to you by any
1st year psy student. Your refusal to accept this possibility can also
be explained to you by any 1st year psy student........


Then do it. In detail, please. I want you to account for ALL of the
phenomena I heard: the Bryston's bass-heaviness, the H-K's reticence,
the Sony TA-N88B's extreme clarity. Explain away!


Simple. You thought you heard it once, and all the rest is
reinforcement. Been there, done that, and the proof of the pudding was
that I *still* heard it, even when the wrong amp was connected!

What you're claiming, is that I 'invent' a sonic signature for the
Harmon-Kardon, Hafler, 2 different Sony, PS Audio, Denon, and Bryston
amps, and not only that, but also keep them consistent over a long
period of time, and unconfused.


Yup, ragazine reviewers do this all the time, re the 'airiness' of
tube amps. the 'bass slam' of Krell amps, the 'inner detail' of SET
amps, ets etc etc. This classification and reinforcement is something
that we humans do all the time, which is why we must control for bias
when performing listening tests.


You forget I had no prior experience or opinion of these products.
Tube amps DO sound different, because they add distortions that are
different from transistor distortions.


No, they don't, if the tube amp is good enough.

To claim some psychological mechanism (as yet unexplained) is
responsible staggers the imagination.


It has been explained to you ad nauseam. The mechanism underlying your
denial can also be explained............


No, not even once. I want mechanisms that create a specific sound
signature, nothing less, or else you offer nothing.


There are no such mechanisms, because they are not needed.

Surely THAT is a far more
'extraordinary claim' than my modest claim: the amps sound different
because they are different.


Nope, because your methodology is *known* to be fatally flawed, and
the flaw is easily proven.


Then prove it. You cannot, of course.


Asked and answered ad nauseam. Your denial does not alter decades of
research.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

  #209   Report Post  
S888Wheel
 
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Default Seeing/hearing and sighted/blind tests

What validation test and results would prove that DBT is not working?
It sounds to me as if this an important piece of information in order
to get this discussion any further.


That is easy. One can insert something that will generate a *known subtle
audible difference* into the random samples.


What's a *known subtle audible difference* that *hasn't* been determined
by controlled comparison methods?

Any examples you'd care to offer?


This seems like a strawman complaint. I never said that the "known subtle
audible difference" had to exist outside the thresholds of human hearing that
has been established in well documented scientific studies.

  #210   Report Post  
Michael Scarpitti
 
Posts: n/a
Default Seeing/hearing and sighted/blind tests

(Nousaine) wrote in message ...
(Michael Scarpitti) wrote:


What you're suggesting is that merely knowing the names of these
products -- and ONLY that -- will 'create' a whole sonic 'signature'
for each!


Big over-generalization. No one has ever suggested that.


Of course you have.

That's preposterous on its face.

Remember, I knew nothing about any of these amps whatsoever, except
what in one case: what I read in the Harmon-Kardon literature.


That makes one wonder why you were 'looking.' But who cares. Just for the
record I'm used to seeing the name Harman spelled without an "o". Am I missing
something?


I really did not spend much time looking at the amps. I just hooked
them up and listened.

If I were 'prone' to hear differences between them that may or may not
have there (your claim), that same 'bias' (your term) should be
equally present regardless of my 'knowledge' of which amp I was
listening to.


Could be; but there are other possible bias factors involved such as input
sensitivities or otherwise un-matched levels or dissimilar programs.


In other words, why should I be MORE 'biased' (your term) by the name
'PS Audio' than 'A'?


Don't know; never said that you were. Appearance is another good mechanism. But
to answer the specific question more specifically much of human bias (not tobe
confused with acoustical bias) is held at the subconscious level and
technically not directly 'known' to the subject at a conscious level. So what?

I'm only concerned with acoustically-based results. Which is why I prefer
listening that does everything it can, given a set-up, to reduce sound quality
and acoustical performance to acoustical factors as much as possible.


I think you misunderstood. Suppose you keep me from seeing either of
two amps, so I don't know their brand names. You call one 'A' and one
'B'. You hook up 'A' for me to my Stax Lambda transformer set-up, and
I listen. Then you switch to 'B', and I listen. How on Earth does that
make any difference? Why is 'A' different from 'Bryston' or 'Sony'? If
I had no more opinion or knowledge of 'Bryston' or 'Sony' than I do of
'A' or 'B', how could it possibly matter? Obviously, it cannot.

I must point out that on several occasions I have made listening tests
that showed no difference. I discussed this before. So, I am quite
capable of detecting no difference as well as some difference.



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