"Harry Lavo" wrote in message

"Arny Krueger" wrote in message
news:%P33b.274985$Ho3.35716@sccrnsc03...
"Dennis Moore" wrote in message
news0X2b.273368$uu5.62103@sccrnsc04

"Wylie Williams" wrote in message

But if there is a simple method I would like to see instructions.
I am considering comparing three amps I own. Normally I would have
just substituted and listened to each a few days, comparing
opinions with my wife as we went along, but I will consider bias
controlled listening. Wylie Williams

Which method of testing makes more sense Wylie? Doing DBT's
or SBT's which you may never use any of these amps for again.

Or hooking them up for a few days. Seeing how you feel about
them at the end of it. And picking the one you feel good about
to keep listening to long term.

..and then never using any of these amps again but the one selected.

Of course, there is nothing that keeps one from "hooking them up for
a few days" under DBT conditions.

Which method of selection comes
closest to matching the long term use of the product?

Since there need not be any difference in the timetable or listening
circumstances for the evaluations, they are equally close to
matching the long term use of the product.

However, I think it needs to be said that long term listening has
been thoroughly investigated under DBT conditions, and found to be
very insensitive when it comes to reliably perceiving small audible
differences.

How about in perceiving less direct but more important "gestalt"
difference? EG, depth of soundstage, focus of instruments, accuracy
of timbre over a range from ppp to fff, etc.

Long term listening is generally said to involve listening for days or
weeks. In contrast, the entire sequence of 9 Beethoven Symphonies can be
listened to in something like 6 hours ( I just did it for the Toscanini and
Walter versions). Suffice it to say, just about any "gestalt" difference can
be revealed in listening tests that are not "long term" as the phrase is
commonly used.

These are the kinds of
things audiophiles can hear in a relaxed, monadic state that they
have trouble believing are imaginary when they are put into the
typical blind a-b or especially a-b-x test which uses much more of a
left -brain approach and based on your own comments here seem mostly
sensitive to frequency response and loudness.

This would appear to be a collection of assertions that lack proximal
factual support.

Again, there's nothing about DBT listening that prohibits any kind of
long-term listening strategy that one might come up with. Many of these
things have been tried and found to provide no joy. OTOH. presentation of
the sonic alternatives in quick succession is a well-known and
generally-recognized means to optimize listener sensitivity.

I believe Dennis is talking about "long term musical satisfaction' which
is
different from pride of ownership.

And you must admit, while possible to do so, it
is unusual for DBT's to be done with switching done on a scale
of days.

snip

So should we be so surprised that a method developed and
found most telling under short term comparisons gives
different than expected results when used for long term
comparison.

DBT's are for detecting subtle audio differences. Long term satisfaction
is often not dependent on subtle differences.


While I don't want to start another DBT debate here, I strongly disagree
with
you. You may consider DBTs useful for detecting 'subtle audible
differences'
but that is exactly what they DON'T reveal. DBTs have been shown to
reveal
gross differences in frequency response and loudness, but little else -
especially with music as a source and with averaged responses of untrained
listeners (normal audiophiles).

IMHO long term listening satisfaction is based on a variety of subtle
audible
differences, such as dynamic shadings, soundstage reproduction, imaging,
tonal
shadings and timbral accuracy.
Regards,
Mike



Yes, Mike got it. I was indeed speaking of long term musical
satisfaction. You of course don't know me, but snobbish or even
genuine pride of ownership isn't why I own something. If I think
it does the music better, and I can afford it then I use it. I have
made some useful, but terrible looking things that stayed in
my system along time. I have had some beautiful equipment,
but the beauty to me was the way it allowed me to enjoy music.
I have at times had barely practical arrangements of equipment
which allowed me musical enjoyment.

Dennis

(Bob Marcus) wrote in message t.net...
(ludovic mirabel) wrote in message news:nsd3b.276882$o%2.127236@sccrnsc02...

See initial discussion below:
Mr. Marcus responds:
If I were a con artist, and wanted to "prove" how acute my hearing
was, this is exactly the method I would use. It's really quite clever
for that purpose. Because the two sides aren't level-matched, it would
be easy to tell when the two sides had been switched. (The image
appears in a different place!) All one has to do is declare a
"preference" on the first trial. After that, since you'll always be
able to tell when the switch has been made, it's hardly a challenge to
declare the same "preference" repeatedly. No wonder you've impressed
your friends with this trick.

Now, why don't you try it level-matched, and double-blind, and then
submit an article to JAES (or even S&V!), so we can see what the
results really are?

bob

Mr. Marcus you give me too much credit. Con artist I may be but
I'm not a magician- the two SIDES are NOT switched- only the
components are.
The room stays where it was. Any differences between its two SIDES
stay where they were, the speakers, the cd.player or the turntable
stay where they were.
The only things switched are the two components-two links
between the sound source and the speakers. They are moved from one
SIDE to the other SIDE And these components should be as level-
comparable as the components were in all the published ABX component
comparison tests- all of them with negative outcomes.
The levels must be close to begin with because TO BEGIN WITH
YOU ADJUST THE LEFT AND RIGHT VOLUMES ON YOUR PREAMP TILL THE MONO
IMAGE IS DEAD CENTRE. If you had much experience with voltmeter you'd
know that very little decibel difference namely 0,5 db. moves the
image right or left. Nothing against using a voltmeter- I got no
revelations when I did.
One needs a particular kind of imagination and /or limited
experience to believe that such kindergarten precautions don't occur
to others.
The monophonic image stays solid with component changes. At
least it does in my room- which does not rotate short of three glasses
of Cognac. How about yours? Does the earth move when you ABX at home?
Mercy- I nearly forgot. Greenhill in his ABX panel cable
testing had TWO out of SIX positive results but ONLY when he was
comparing a thick and a thin cable with 1,75 db. level difference
between them- and ONLY when using pink noise for his signal- not
music.
These two results are immortalised as "Marcus-Ovchain positive
1,75db. test" because you claimed it as your one and only evidence
that ABX can give positive results when comparing components and
Ovchain was applauding on the sidelines. That explains why you think
that 1,75 db at say 4000hz would be missed by anyone not terminally
deaf. For your information- these old ears detect a 0,5 db change in
volume when switching my stepped volume controls.
I promise to reflect on your con artistry connoisseurship in
my spare time.
Ludovic Mirabel
P.S. I'll contact JAES after you quote one single ABX
component comparison report that appeared there.
While waiting I described the left-right method in an article
in a Guest Editorial in the "Audio Electronics" #5, '98, p6.
I'll mail the Editor your posting . He'll be saddened to hear
how foolish he was to fall for my con act, and no doubt invite you to
contribute as a scientist-vigilante on psychometrics, acoustics,
electronics etc.

"Arny Krueger" wrote:




"Dennis Moore" wrote in message
news:Wud3b.277945$Ho3.37329@sccrnsc03
"Arny Krueger" wrote in message
news:%P33b.274985$Ho3.35716@

However, I think it needs to be said that long term listening has
been thoroughly investigated under DBT conditions, and found to be
very insensitive when it comes to reliably perceiving small audible
differences.

And it precisely this difference that keeps people wondering
about DBT's.

Why? Is there valid, reliable a-priori evidence that DBTs fail to detect
audible differences?

Equipment that supposedly sounds identical
under conditions of DBT's gives different levels of satisfaction
long term.

Isn't there more to audio equipment than just sound quality?

And you must admit, while possible to do so, it
is unusual for DBT's to be done with switching done on a scale
of days.

Once one finds that something is futile, one is not encouraged to spend a
tremendous amount of time with it.

So should we be so surprised that a method developed and
found most telling under short term comparisons gives
different than expected results when used for long term
comparison.

There's no reliable evidence that this is the case. Indeed, there is
reliable evidence that this is NOT the case.

Indeed, Mr Moore's assertion has no evidentiary content. It's just his opinion
that this happens. It also may be partly a subtle corollary extension of the
break-in merchandising mythology.

(ludovic mirabel) wrote in message news:xDA3b.220180$cF.73109@rwcrnsc53...
(Bob Marcus) wrote in message t.net...
(ludovic mirabel) wrote in message news:nsd3b.276882$o%2.127236@sccrnsc02...

See initial discussion below:
Mr. Marcus responds:
If I were a con artist, and wanted to "prove" how acute my hearing
was, this is exactly the method I would use. It's really quite clever
for that purpose. Because the two sides aren't level-matched, it would
be easy to tell when the two sides had been switched. (The image
appears in a different place!) All one has to do is declare a
"preference" on the first trial. After that, since you'll always be
able to tell when the switch has been made, it's hardly a challenge to
declare the same "preference" repeatedly. No wonder you've impressed
your friends with this trick.

Now, why don't you try it level-matched, and double-blind, and then
submit an article to JAES (or even S&V!), so we can see what the
results really are?

bob

Mr. Marcus you give me too much credit. Con artist I may be

Actually, I don't think you're conning anyone.

but
I'm not a magician- the two SIDES are NOT switched- only the
components are.
The room stays where it was. Any differences between its two SIDES
stay where they were, the speakers, the cd.player or the turntable
stay where they were.
The only things switched are the two components-two links
between the sound source and the speakers. They are moved from one
SIDE to the other SIDE And these components should be as level-
comparable as the components were in all the published ABX component
comparison tests- all of them with negative outcomes.

Ah, so you do level-match them. I thought you said that wasn't
necessary.

The levels must be close to begin with because TO BEGIN WITH
YOU ADJUST THE LEFT AND RIGHT VOLUMES ON YOUR PREAMP TILL THE MONO
IMAGE IS DEAD CENTRE. If you had much experience with voltmeter you'd
know that very little decibel difference namely 0,5 db. moves the
image right or left. Nothing against using a voltmeter- I got no
revelations when I did.

But you used one, right? Because you absolutely have to, you know. Or
rather, your lovely assistant has to, because if YOU adjusted levels
after SHE switched the components, it wouldn't even be single-blind,
now would it?

One needs a particular kind of imagination and /or limited
experience to believe that such kindergarten precautions don't occur
to others.

If all you're using are kindergarten precautions, I'm afraid we have a
bias control problem.

The monophonic image stays solid with component changes. At
least it does in my room- which does not rotate short of three glasses
of Cognac. How about yours? Does the earth move when you ABX at home?

Do it double-blind with an impartial witness, and show us the data.

Mercy- I nearly forgot. Greenhill in his ABX panel cable
testing had TWO out of SIX positive results but ONLY when he was
comparing a thick and a thin cable with 1,75 db. level difference
between them- and ONLY when using pink noise for his signal- not
music.
These two results are immortalised as "Marcus-Ovchain positive
1,75db. test" because you claimed it as your one and only evidence
that ABX can give positive results when comparing components and
Ovchain was applauding on the sidelines. That explains why you think
that 1,75 db at say 4000hz would be missed by anyone not terminally
deaf. For your information- these old ears detect a 0,5 db change in
volume when switching my stepped volume controls.

I am quite through trying to argue with you about Greenhill's tests.
Everything you have written about them has been wrong (save, perhaps,
the date of publication), and although you have been corrected many
times by many people here, you persist in your misreporting. I can
only assume that is willful.

I once again invite anyone who actually cares to look up the original
article and find out what Greenhill really said.

bob

Bob Marcus wrote:
(ludovic mirabel) wrote in message news:%wV4b.329114$o%2.151942@sccrnsc02...

Mr. Marcus said:
If I were a con artist, and wanted to "prove" how acute my hearing
was, this is exactly the method I would use. It's really quite clever
for that purpose.

Mr. Williams asked for a method less complicated than ABX. Very
hesitantly, knowing the ways of some in the RAHE I summarised a
method that was accepted and published by the "Audio Amateur". Only to
be told by an expert called Marcus that it was a "con artist method,
devised to just "prove" my acute hearing.

I said it COULD be used that way. I also said I didn't think you were
conning anyone.

snip

A simple task in my case : I have volume controls stepped in 0,5
db.
steps.

And you think 0.5 dB is close enough???

snip some more

Eg. The bass is distorted on one side of your room but you still
have a statistically significant positive results:

Wait--do you have any significant positive results? You haven't posted
any.

snip yet again

There are more things wrong with your left-right method than I can
count. Basically, you're asking your brain to sort out sounds in a way
it isn't wired to. So, in theory at least, it should not work. I will
be perfectly willing to concede that it does work, however, if you
will do the following:

1) Level-match to within 0.1 dB (the usual standard, I believe).

2) Perform the tests double-blind, with an independent witness.

3) Report the results in full.

Until you do that, all you're offering is a theoretical approach
that's contradicted by all existing theory. And given that the
existing theory has been developed over decades by people far more
expert in the field than you or me, that doesn't give you much ground
to stand on.

bob


Actually I don't think anyone is interested in doing a test to find
differences/preferences this way. Example: an important parameter of an
audio component is its ability to convey image. This test uses mono
signals and only exercises one channel of the device under test. I
thought one of the biggest complaints of the original poster was that
the DBT test is different than how people listen to their stereos. This
L/R test is so different than the way we listen to audio equipment that
I am totally surprised that he would even consider it. Not to mention
the fact that any dynamic interchannel effects (like crosstalk, power
supply effects, imbalance of frequency response in a RIAA circuit, etc.)
will be totally undetected. The more I think about the test, the more I
am amazed at what it does not do.

"Bob Marcus" wrote in message
A simple task in my case : I have volume controls stepped in 0,5
db.
steps.

And you think 0.5 dB is close enough???

snip some more


Well if there is a .5dB difference he could go up or down to match
exactly. With .5 dB steps, the maximum difference between two
sources will be .25 dB. And often would be less. At one time the
standard was within .2dB which eventually was reduced to .1 dB.
At least some of the time you could be testing components that
were this close. Would be a good move to measure it and see
that it is. But the .5 dB steps don't automatically make the
level differences too large.

Dennis

(Bob Marcus) wrote in message news:xJo5b.342306$YN5.233613@sccrnsc01...
(ludovic mirabel) wrote in message news:%wV4b.329114$o%2.151942@sccrnsc02...

Mr. Marcus said:

Snip:
There are more things wrong with your left-right method than I can
count. Basically, you're asking your brain to sort out sounds in a way
it isn't wired to. So, in theory at least, it should not work.

Exactly which theory about "how the brain is wired" is against turning
your head from left to right to compare sounds. I missed it in the
neurophysiology reports I read. A few references and quotes, please.
Just to enlighten me.

I will be perfectly willing to concede that it does work, however, if you
will do the following:
1) Level-match to within 0.1 dB (the usual standard, I believe).
2) Perform the tests double-blind, with an independent witness.
3) Report the results in full.

Your " willing to concede" is a real incentive. It will open the
gates, no doubt, to respectability amongst electronics' engs,
psychometricians, my professional cousins neurologists and neuro
physiologists, all the folk who are awaiting your word.

Until you do that, all you're offering is a theoretical approach
that's contradicted by all existing theory. And given that the
existing theory has been developed over decades by people far more
expert in the field than you or me, that doesn't give you much ground
to stand on.

bob

Help "us' out with a few points:
1) I said several times that I'm proposing an ad hoc, imperfect,
nonscientific, non researched way to avoid bias It only just an
elaboration of covering the brand names. It is meant to be used by
whoever feels that he'd like to attempt some degree of bias control,
very simply, at his home, without using $600:00 switch, and without a
DBT method which requires training and, at that, is still
controversial (ah, theory!) after 30 years of use in this application.
It is not even for everyone. Some, I'm sure will not like it- and
that's the end of the matter- as lonng as they have facts not theories
to report.

I said also that speculative theoretical objections from those
without hands-on experience are of little interest to me.
But since you insist on taking me there it would help if you quoted a
few names and references to YOUR research experts in "existing
theory" WITH DIRECT RELEVANCE TO SIMULTANEOUS COMPONENT COMPARISONS
WITH RANDOM CHANGES FROM SIDE TO SIDE. So far we have your
interpretative report only of what those anonymous experts are
supposed to have said but no doubt you have "many" references at your
fingertips.

2) Your strict conditions for "conceding" would make sense if,
blazing the path to a better alternative, YOU had done all these
things- to avoid bias- in YOUR component choices. You must have tested
them before purchase with 0,1 db level matching, double blind
precautions and independent witnesses- don't forget witnesses. Do you
own the ABX switch?
It would be interesting to hear what was the otcome of those trials
and what system did you collect using these rigid research methods.

3) I missed any further discussion of your theory of the moving
centre image as one moves components from side to side. Remember?

Surely it wouldn't be that you'd like to divert attention from that
"misreporting" (or was it "misunderstanding"?) to a "theoretical"
argument about irrelevancies? (see footnote). I wish I could
concentrate your mind on this crucial topic: Does the central image
move as you move the components from side to side or does it stay
steady? 0,1 db level difference or 0,2 or or 0.5 or 1,75- whatever .
Ludovic Mirabel

Footnote Marcus explained:
Because the two sides aren't level-matched, it would
be easy to tell when the two sides had been switched. (The image
appears in a different place!)

No it does not, It stays rock-solid throughout (see below)

All one has to do is declare a
"preference" on the first trial. After that, since you'll always
be able to tell when the switch has been made, ..

Yes, you will or not but not because "the image appears in a different
place". It does not.
The component are Xmoved from side to side but the levels between the
two sides do not change. Elementary: you do not use components with
different output levels in ABX , you do not use them in left-right.
Unless you're deliberately testing for the threshhold of level-
perception and use eg. two wires of different diameter
If you do, you get the Marcus-Ovchain 1,75db "positive" ABX test.
Automatically.

As explained to you, twice, very exact level matching is completely
unnecessary in the left-right simultaneous comparison. If the
better-liked component is moved to the less favoured side of the room
and yet is still identified , it REINFORCES the validity of the
result.
Surely it is not THAT difficult to grasp.
But of course there is nothing against exact level matching should you
so wish.
If you HAVEN'T graspED it YET I despair of explaining it to you.
Knowing your scrupulous probity in an argument I'd never suspect that
your 0,1db, reliable witnesses and the rest is just a lot of
squid-ink.
L.M.

chung wrote in message ...
Bob Marcus wrote:
(ludovic mirabel) wrote in message news:%wV4b.329114$o%2.151942@sccrnsc02...
Snip previous discussion.

Chung said:
Actually I don't think anyone is interested in doing a test to find
differences/preferences this way. Example: an important parameter of an
audio component is its ability to convey image. This test uses mono
signals and only exercises one channel of the device under test. I
thought one of the biggest complaints of the original poster was that
the DBT test is different than how people listen to their stereos. This
L/R test is so different than the way we listen to audio equipment that
I am totally surprised that he would even consider it. Not to mention
the fact that any dynamic interchannel effects (like crosstalk, power
supply effects, imbalance of frequency response in a RIAA circuit, etc.)
will be totally undetected. The more I think about the test, the more I
am amazed at what it does not do.

I am completely flabbergasted. When you say: "This test uses mono
signals and only exercises one channel of the device under test" do
you mean that you concluded that I'm using ONE channel at a time?
I'm upset because it proves that I'm unable to communicate very
obvious and simple ideas to some readers. And it saddens me that you'd
attribute such brain-lame ideas to me.
Of course BOTH channels are playing at the same time.
The channel levels are matched before the first change and never
touched after that.
Your assistant Xchanges the two components (which of course are
electrically comparable) at random from one side to the other.
The subject either does or does not consistently recognise the
locations . Perhaps you missed the long word in capitals
SIMULTANEOUSLY- I'm reposting it for your attention .
I'm reposting also the explanation why slight level difference
REINFORCES the validity of a correct answerif anything. If that too is
not clear please don't hesitate to ask.
You reproach me for repetition but it would appear that I have not yet
repeated myself enough.
Reprint: (regretfully and with apologies)
1) Get a monophonic or near monophonic (eg. centred soprano) signal
source. MUSICAL, not an artefact.
2) On the left insert one component, on the right the OTHER ONE- (in
the case of interconnects using two of one kind together i.e.source to
preamp and preamp to amp on each side will give better contrast.)
3) Listen -write down your preference, get blinded.
4) An assistant now changes AT RANDOM (coin throw) both components
from one side to the other or (of course) leaves them where they are
keeping the records.
5) This is repeated minimum 15 times- for any length of time and with
interval for lunch if you like. EVERY TIME you note your
preference
The repetition and change are the CRUX.

At this point INVARIABLY someone says: No good, room sides differ,
levels differ subtly etc.
Answer;If there are differences between room sides, speaker volumes
etc. and yet you still prefer and locate one of the two component as
it moves from "good" to thje "bad"side surely, that REINFORCES the
results- yes? no?
Eg. The bass is distorted on one side of your room but you still
have a statistically significant positive result: "I (...recognise)
and prefer the sound of this preamp on EITHER side."
The comparison is not just (supposedly) "instantaneous"- it is
SIMULTANEOUS.
The theoretical objections from people who never tried it
are of little interest.
Addendum: This is not a research test. No test, not DBT, exists FOR
THIS APPLICATION that is validated by properly conducted research. The
inferences from other fields (eg. medicine, psychometrics etc) are
apple and oranges.
Consider just this for one thing. The crux in medical research is
proper selection of the subjects to get representative outcome
numbers: age, gender, age, race, social backgrounds, dietary and other
habits and so on.
How do you select a representative panel for component comparison
tests. Just untrained audiophiles? You'll get untrained "They all
sound the same answer".
Trained, middle-ahed chamber music lovers? Well you got a huge
selection bias.

The truth that our scientists will not face is that NO PROPERLY
RESEARCHED TEST , WITH THE VARIETY OF THE AUDIOPHILE SPECIES COMPARING
MUSICAL QUALITIES OF COMPONENTS, EXISTS AND THAT NONE IS POSSIBLE IN
THE PRESENT STATE OF KNOWLEDGE. (Repetition again).
Ludovic Mirabel

On Fri, 05 Sep 2003 05:28:24 GMT, (ludovic
mirabel) wrote:

I am completely flabbergasted. When you say: "This test uses mono
signals and only exercises one channel of the device under test" do
you mean that you concluded that I'm using ONE channel at a time?
I'm upset because it proves that I'm unable to communicate very
obvious and simple ideas to some readers. And it saddens me that you'd
attribute such brain-lame ideas to me.

I am completely flabbergasted that you'd be surprised by such an
attribution..... :-)

Of course BOTH channels are playing at the same time.

That is exactly the problem. You have at best a 6dB signal to noise
ratio between the reference channel and the channel containing the
unit under test. This will pretty well guarantee the masking of any
real but subtle differences.

To claim, as you do, that this works *better* than a time-proximate
'ABX' test, is contrary to everything we know about human hearing -
and that is a *lot* more than the 'subjectivists' care to believe.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

(ludovic mirabel) wrote in message news:38U5b.269475$Oz4.71805@rwcrnsc54...
(Bob Marcus) wrote in message news:xJo5b.342306$YN5.233613@sccrnsc01...
(ludovic mirabel) wrote in message news:%wV4b.329114$o%2.151942@sccrnsc02...

Mr. Marcus said:

Snip:
There are more things wrong with your left-right method than I can
count. Basically, you're asking your brain to sort out sounds in a way
it isn't wired to. So, in theory at least, it should not work.

Exactly which theory about "how the brain is wired" is against turning
your head from left to right to compare sounds. I missed it in the
neurophysiology reports I read. A few references and quotes, please.
Just to enlighten me.

I meant only that the brain is wired to synthesize the sound it hears
from the two channels. That's how stereo works, after all. Your method
forces you to work against that.

I will be perfectly willing to concede that it does work, however, if you
will do the following:
1) Level-match to within 0.1 dB (the usual standard, I believe).
2) Perform the tests double-blind, with an independent witness.
3) Report the results in full.

Your " willing to concede" is a real incentive. It will open the
gates, no doubt, to respectability amongst electronics' engs,
psychometricians, my professional cousins neurologists and neuro
physiologists, all the folk who are awaiting your word.

Until you do that, all you're offering is a theoretical approach
that's contradicted by all existing theory. And given that the
existing theory has been developed over decades by people far more
expert in the field than you or me, that doesn't give you much ground
to stand on.

bob

Help "us' out with a few points:
1) I said several times that I'm proposing an ad hoc, imperfect,
nonscientific, non researched way to avoid bias It only just an
elaboration of covering the brand names. It is meant to be used by
whoever feels that he'd like to attempt some degree of bias control,
very simply, at his home, without using $600:00 switch, and without a
DBT method which requires training

Actually, to be any good, your method would require at least as much
training. After all, you're listening for the exact same artifacts.
(And, as I noted above, you're listening for them under rather more
challenging circumstances.)

and, at that, is still
controversial (ah, theory!) after 30 years of use in this application.

Not among the people who use it regularly to design and test audio
components, among other things. It's only "controversial" because some
people are uncomfortable with its results and deal with the resulting
cognitive dissonance by maintaining a willful ignorance about it.

It is not even for everyone. Some, I'm sure will not like it- and
that's the end of the matter- as lonng as they have facts not theories
to report.

But, as I keep pointing out, you have NO facts to report.

I said also that speculative theoretical objections from those
without hands-on experience are of little interest to me.

That is evident. However, those to whom you are recommending this
method might be interested to know just how well it has been
validated. That is, not at all.

But since you insist on taking me there it would help if you quoted a
few names and references to YOUR research experts in "existing
theory" WITH DIRECT RELEVANCE TO SIMULTANEOUS COMPONENT COMPARISONS
WITH RANDOM CHANGES FROM SIDE TO SIDE. So far we have your
interpretative report only of what those anonymous experts are
supposed to have said but no doubt you have "many" references at your
fingertips.

2) Your strict conditions for "conceding" would make sense if,
blazing the path to a better alternative, YOU had done all these
things- to avoid bias- in YOUR component choices. You must have tested
them before purchase with 0,1 db level matching, double blind
precautions and independent witnesses- don't forget witnesses. Do you
own the ABX switch?
It would be interesting to hear what was the otcome of those trials
and what system did you collect using these rigid research methods.

Ah, but I can point to published results done by people who did. You
can't.

3) I missed any further discussion of your theory of the moving
centre image as one moves components from side to side. Remember?

Surely it wouldn't be that you'd like to divert attention from that
"misreporting" (or was it "misunderstanding"?) to a "theoretical"
argument about irrelevancies? (see footnote). I wish I could
concentrate your mind on this crucial topic: Does the central image
move as you move the components from side to side or does it stay
steady? 0,1 db level difference or 0,2 or or 0.5 or 1,75- whatever .

Well, let's say you have two amps that aren't precisely level-matched.
When you switch them side-to-side, the louder amp is now on the other
side. Doesn't that shift the image? And doesn't that provide the
supposedly blinded test subject with a rather obvious clue as to
whether the amps have been switched or not? And since that clue is
based entirely on level, rather than on the distinctive sound of the
two amps, doesn't that render the test pretty much meaningless?

Ludovic Mirabel

Footnote Marcus explained:
Because the two sides aren't level-matched, it would
be easy to tell when the two sides had been switched. (The image
appears in a different place!)

No it does not, It stays rock-solid throughout (see below)

All one has to do is declare a
"preference" on the first trial. After that, since you'll always
be able to tell when the switch has been made, ..

Yes, you will or not but not because "the image appears in a different
place". It does not.
The component are Xmoved from side to side but the levels between the
two sides do not change. Elementary: you do not use components with
different output levels in ABX , you do not use them in left-right.
Unless you're deliberately testing for the threshhold of level-
perception and use eg. two wires of different diameter
If you do, you get the Marcus-Ovchain 1,75db "positive" ABX test.
Automatically.

As explained to you, twice, very exact level matching is completely
unnecessary in the left-right simultaneous comparison. If the
better-liked component is moved to the less favoured side of the room
and yet is still identified , it REINFORCES the validity of the
result.

Not if the image shift tells the listener that the device favored in
the first test is now on the other side. In that case, the two trials
are not independent.

Surely it is not THAT difficult to grasp.

Tsk, tsk. Another condescending remark slip past the moderators.

bob

p.s.: Just for fun, check out a real expert's take on the problems
with simultaneous left-right comparisons:

http://groups.google.com/groups?hl=e...cs.cornell.edu

(Stewart Pinkerton) wrote in message ...
On Fri, 05 Sep 2003 05:28:24 GMT, (ludovic
mirabel) wrote:

I am completely flabbergasted. When you say: "This test uses mono
signals and only exercises one channel of the device under test" do
you mean that you concluded that I'm using ONE channel at a time?
I'm upset because it proves that I'm unable to communicate very
obvious and simple ideas to some readers. And it saddens me that you'd
attribute such brain-lame ideas to me.

I am completely flabbergasted that you'd be surprised by such an
attribution..... :-)

Of course BOTH channels are playing at the same time.

That is exactly the problem. You have at best a 6dB signal to noise
ratio between the reference channel and the channel containing the
unit under test. This will pretty well guarantee the masking of any
real but subtle differences.

To claim, as you do, that this works *better* than a time-proximate
'ABX' test, is contrary to everything we know about human hearing -
and that is a *lot* more than the 'subjectivists' care to believe.

It is now the RAHE time to make lightning and thunder shouting
with dramatised indignation: "Quote one sentence of mine claiming that
it works better or you'll see my seconds this evening" But I won't.
I'm not that anxious to win.
No I never said that it works "better" than whatever. If I let
slip something like that I recant. It works better for me and for some
others. Quite likely not for everyone
You see I don't believe that a universally valid "test" for
comparing audio components exists. I gave my reasons too many times
already but will again if you insist.
Your theory why it shouldn't work is very interesting. 6db is
good enough for me. I don't mind if you believe me or not, I'm not
trademarking anything.
I said before that my platoon seargent (in Scotland BTW) used
to say "Practical life f.... theory"
Try my nontest and then report back. 6db. and all.
Ludovic Mirabel

(Bob Marcus) wrote in message ...
(ludovic mirabel) wrote in message news:38U5b.269475$Oz4.71805@rwcrnsc54...
(Bob Marcus) wrote in message news:xJo5b.342306$YN5.233613@sccrnsc01...
(ludovic mirabel) wrote in message news:%wV4b.329114$o%2.151942@sccrnsc02...


Big snip. I said:
Surely it is not THAT difficult to grasp.

Tsk, tsk. Another condescending remark slip past the moderators.

bob

p.s.: Just for fun, check out a real expert's take on the problems
with simultaneous left-right comparisons:

http://groups.google.com/groups?hl=e...cs.cornell.edu

I'll get to the snipped portion of this posting, with Mr. Marcus
latest revision of his "brain- wiring" theory, sometime later- after
a lunch and a snooze.
But here for the 2nd. time in 24 hrs Mr. Marcus sees fit to start
special pleading for censorship- first in regard to Mr. Lang's text in
the "Audiophile Press" thread, and now in regard to mine.
And once againhe does it in the main forum not in the "discuss"
subforum created specifically for discussion of moderating problems.
And these his remarks "slip past the moderators" as he puts it,
confirming my opinion in the "Audiophile Press" thread that the new
guidelines are not only emasculating but also very, very difficult to
administer fairly.
And his delicate sense of propriety (he doesn't like
"condescension") does not extend to insinuation like
"REAL expert's take" against mine obviously very "UNREAL"
expertise ( the honour by the way I never claimed).
So I had a look at Sean Olive's text.
It seems that someone posted a letter in the "Stereophile" proposing
comparing components placed one on the left the other one on the right
side. Period. No RANDOM CHANGES from side to side which are the CRUX
of the left-right method. (I repeated it so many times that by now it
nearly sends me to sleep).
S. Olive as befits a real scientist spends many lines proving that
a stupid method is indeed a stupid method.
But where is our Mr. Marcus in all this? Why does he grab onto
this 100% irrelevancy, pins it on me, clouds the issue and sends
readers on a 100% irrelevant wild goose chase? It wouldn't be because
he's hard-pressed for a rational argument, would it?
Well, we've been there before. He did the same in regard to his
let's call it... "misreporting" of Greenhill's article. There too he
made , let's say... "mistaken" claims that suited his case and when
faced with Greenhill's own tables and conclusions sent the readers "to
see for themselves".
When I quoted ALL the relevant portions of Greenhill's
conclusions verbatim and challenged him to give one single quote
contradicting it, he seeming somewhat upset and irritable, said that
he'll no longer discuss Greenhill in RAHE.
What now Mr. Marcus? Will you still discuss S. Olive's
opinions or refuse to, forcing me to quote all of it here?
Ludovic Mirabel

"Dennis Moore" wrote:


"Bob Marcus" wrote in message
A simple task in my case : I have volume controls stepped in 0,5
db.
steps.

And you think 0.5 dB is close enough???

snip some more


Well if there is a .5dB difference he could go up or down to match
exactly. With .5 dB steps, the maximum difference between two
sources will be .25 dB. And often would be less. At one time the
standard was within .2dB which eventually was reduced to .1 dB.

Just to be clear the standard has always been +/- 0.1 which is 0.2 dB when not
expressed as a range.

ludovic mirabel wrote:
chung wrote in message ...
Bob Marcus wrote:
(ludovic mirabel) wrote in message news:%wV4b.329114$o%2.151942@sccrnsc02...
Snip previous discussion.

Chung said:
Actually I don't think anyone is interested in doing a test to find
differences/preferences this way. Example: an important parameter of an
audio component is its ability to convey image. This test uses mono
signals and only exercises one channel of the device under test. I
thought one of the biggest complaints of the original poster was that
the DBT test is different than how people listen to their stereos. This
L/R test is so different than the way we listen to audio equipment that
I am totally surprised that he would even consider it. Not to mention
the fact that any dynamic interchannel effects (like crosstalk, power
supply effects, imbalance of frequency response in a RIAA circuit, etc.)
will be totally undetected. The more I think about the test, the more I
am amazed at what it does not do.

I am completely flabbergasted. When you say: "This test uses mono
signals and only exercises one channel of the device under test" do
you mean that you concluded that I'm using ONE channel at a time?

No. You were saying that you compared *one* channel of one product vs.
*one* channel of another product. You were listening to both L and R
channels, but those channels were processed by different pieces of
equipment (for example, L channel came from one channel of amp A, and
right channel came from one channel of amp B). And you said you were
using mono material.

I'm upset because it proves that I'm unable to communicate very
obvious and simple ideas to some readers. And it saddens me that you'd
attribute such brain-lame ideas to me.

You said it, not me .

Please answer this: how do you compare the stereo image ability of one
product vs another using your method?

Of course BOTH channels are playing at the same time.
The channel levels are matched before the first change and never
touched after that.
Your assistant Xchanges the two components (which of course are
electrically comparable) at random from one side to the other.
The subject either does or does not consistently recognise the
locations . Perhaps you missed the long word in capitals
SIMULTANEOUSLY- I'm reposting it for your attention .
I'm reposting also the explanation why slight level difference
REINFORCES the validity of a correct answerif anything. If that too is
not clear please don't hesitate to ask.
You reproach me for repetition but it would appear that I have not yet
repeated myself enough.
Reprint: (regretfully and with apologies)
1) Get a monophonic or near monophonic (eg. centred soprano) signal
source. MUSICAL, not an artefact.
2) On the left insert one component, on the right the OTHER ONE- (in
the case of interconnects using two of one kind together i.e.source to
preamp and preamp to amp on each side will give better contrast.)
3) Listen -write down your preference, get blinded.
4) An assistant now changes AT RANDOM (coin throw) both components
from one side to the other or (of course) leaves them where they are
keeping the records.
5) This is repeated minimum 15 times- for any length of time and with
interval for lunch if you like. EVERY TIME you note your
preference
The repetition and change are the CRUX.

So far, it seems like I understand your method. You are trying to find a
preference of one product over another, by comparing one channel of one
product vs one channel of the other product. As I said before, this is
very different than the way you listen to music, which is using both
channels of the same product(s) at the same time.

The rest of your post snipped, due to repetition of previously posted
material.



Ludovic Mirabel

chung wrote in message ...
ludovic mirabel wrote:
chung wrote in message ...
Bob Marcus wrote:
(ludovic mirabel) wrote in message news:%wV4b.329114$o%2.151942@sccrnsc02...
Snip previous discussion.

Chung said:
Actually I don't think anyone is interested in doing a test to find
differences/preferences this way. Example: an important parameter of an
audio component is its ability to convey image. This test uses mono
signals and only exercises one channel of the device under test. I
thought one of the biggest complaints of the original poster was that
the DBT test is different than how people listen to their stereos. This
L/R test is so different than the way we listen to audio equipment that
I am totally surprised that he would even consider it. Not to mention
the fact that any dynamic interchannel effects (like crosstalk, power
supply effects, imbalance of frequency response in a RIAA circuit, etc.)
will be totally undetected. The more I think about the test, the more I
am amazed at what it does not do.

I am completely flabbergasted. When you say: "This test uses mono
signals and only exercises one channel of the device under test" do
you mean that you concluded that I'm using ONE channel at a time?

No. You were saying that you compared *one* channel of one product vs.
*one* channel of another product. You were listening to both L and R
channels, but those channels were processed by different pieces of
equipment (for example, L channel came from one channel of amp A, and
right channel came from one channel of amp B). And you said you were
using mono material.

I'm upset because it proves that I'm unable to communicate very
obvious and simple ideas to some readers. And it saddens me that you'd
attribute such brain-lame ideas to me.

You said it, not me .

A great quip. How do you think of such funny things to say just
like that on the spur of the moment.? I said it, not you

Please answer this: how do you compare the stereo image ability of one
product vs another using your method?

I don't. It is not perfect. Just a compromise for easy use at home.
Shall I say what else is not perfect in other tests for comparing
components?
Of course BOTH channels are playing at the same time.
The channel levels are matched before the first change and never
touched after that.
Your assistant Xchanges the two components (which of course are
electrically comparable) at random from one side to the other.
The subject either does or does not consistently recognise the
locations . Perhaps you missed the long word in capitals
SIMULTANEOUSLY- I'm reposting it for your attention .
I'm reposting also the explanation why slight level difference
REINFORCES the validity of a correct answerif anything. If that too is
not clear please don't hesitate to ask.
You reproach me for repetition but it would appear that I have not yet
repeated myself enough.
Reprint: (regretfully and with apologies)
1) Get a monophonic or near monophonic (eg. centred soprano) signal
source. MUSICAL, not an artefact.
2) On the left insert one component, on the right the OTHER ONE- (in
the case of interconnects using two of one kind together i.e.source to
preamp and preamp to amp on each side will give better contrast.)
3) Listen -write down your preference, get blinded.
4) An assistant now changes AT RANDOM (coin throw) both components
from one side to the other or (of course) leaves them where they are
keeping the records.
5) This is repeated minimum 15 times- for any length of time and with
interval for lunch if you like. EVERY TIME you note your
preference
The repetition and change are the CRUX.

So far, it seems like I understand your method. You are trying to find a
preference of one product over another, by comparing one channel of one
product vs one channel of the other product. As I said before, this is
very different than the way you listen to music, which is using both
channels of the same product(s) at the same time.

It is. It is not perfect. It does not pretend to be scientific.
Shall I say what other test method is not like listening to music?
Especially if you're using pink noise that some of your colleagues
(perhaps not you, in which case I apologise) claim is the best testing
signal for that other well-publicised "test".
The rest of your post snipped, due to repetition of previously posted
material.

On the whole if this is all you can criticise a reader might take it
as a recommendation.
By the way- did you try it?

Ludovic Mirabel

ludovic mirabel wrote:
chung wrote in message ...
ludovic mirabel wrote:
chung wrote in message ...
Bob Marcus wrote:
(ludovic mirabel) wrote in message news:%wV4b.329114$o%2.151942@sccrnsc02...
Snip previous discussion.

Chung said:
Actually I don't think anyone is interested in doing a test to find
differences/preferences this way. Example: an important parameter of an
audio component is its ability to convey image. This test uses mono
signals and only exercises one channel of the device under test. I
thought one of the biggest complaints of the original poster was that
the DBT test is different than how people listen to their stereos. This
L/R test is so different than the way we listen to audio equipment that
I am totally surprised that he would even consider it. Not to mention
the fact that any dynamic interchannel effects (like crosstalk, power
supply effects, imbalance of frequency response in a RIAA circuit, etc.)
will be totally undetected. The more I think about the test, the more I
am amazed at what it does not do.

I am completely flabbergasted. When you say: "This test uses mono
signals and only exercises one channel of the device under test" do
you mean that you concluded that I'm using ONE channel at a time?

No. You were saying that you compared *one* channel of one product vs.
*one* channel of another product. You were listening to both L and R
channels, but those channels were processed by different pieces of
equipment (for example, L channel came from one channel of amp A, and
right channel came from one channel of amp B). And you said you were
using mono material.

I'm upset because it proves that I'm unable to communicate very
obvious and simple ideas to some readers. And it saddens me that you'd
attribute such brain-lame ideas to me.

You said it, not me .

A great quip. How do you think of such funny things to say just
like that on the spur of the moment.? I said it, not you

It's funny because if I had made that comment, it would not have passed
moderation.


Please answer this: how do you compare the stereo image ability of one
product vs another using your method?

I don't. It is not perfect. Just a compromise for easy use at home.
Shall I say what else is not perfect in other tests for comparing
components?

Not perfect? How about close to useless? If you read audio reviews,
stereo imaging is one of the biggest measures of how well a piece of
gear is perceived. When you read about differences between amps, wires,
CD players, etc., inevitably the ability to produce pin-point imaging is
a necessary property of a desirable audio product, and it's what
differentiates products. How can you set up a preference without
observing how well the imaging is?

You have other major problems, too. If you only test one channel of a
product, you are essentially ignoring all the (a) interchannel effects
like crosstalk, matching, etc., as well as (b) not exercising a product
under actual-use conditions like driving *both* channels. What if the
power supply cannot handle driving two channels to the loudness you
want? Does anyone really listen to equipment the way you do your test?

(snip)
The repetition and change are the CRUX.

No, the imperfections that you tried to glance over are the crux of why
yours is a poor method.


So far, it seems like I understand your method. You are trying to find a
preference of one product over another, by comparing one channel of one
product vs one channel of the other product. As I said before, this is
very different than the way you listen to music, which is using both
channels of the same product(s) at the same time.

It is. It is not perfect. It does not pretend to be scientific.

That part is definitely clear. Another big problem is that the test is
very poorly controlled. As others have pointed out, the left and right
speakers do not sound the same even if they are the same model, due to
placement and room acoustics. When you tried to equalize level, using a
mono or "mostly mono" source, you are balancing left and right at a
small subset of audible frequencies (and 0.5 dB steps are not fine
enough BTW, and have you confirmed that they are actually 0.5dB steps?).
Those speakers will not be giving identical response over the complete
audio range. Therefore, in your listening test, if you use "mostly mono"
or stereo material, there will be imaging cues. For instance, if you use
mostly mono source the 1st violin may sound a little bit left of center
in one setting, but if left and right were swapped, it will sound a
little bit right of center. That tells you L-R has been swapped. That
makes the test poorly controlled since the subject knows something has
changed.

Shall I say what other test method is not like listening to music?

With DBT, you can listen to music the way you normally audition
equipment at a store, i.e., listen for differences in normal
reproduction. Plus, DBT exercises the equipment the way they are meant
to be used. Huge improvements over yours.

Especially if you're using pink noise that some of your colleagues
(perhaps not you, in which case I apologise) claim is the best testing
signal for that other well-publicised "test".
The rest of your post snipped, due to repetition of previously posted
material.

On the whole if this is all you can criticise a reader might take it
as a recommendation.

Huh? That is all I can criticize? Have you read carefully? Have you
skipped the other "concerns" posted here? In fact, I have not found one
thing about your method that is an improvement over DBT.

By the way- did you try it?

No, and certainly no plans to, given these huge deficiencies of your method.


Ludovic Mirabel

chung wrote in message . net...
ludovic mirabel wrote:
chung wrote in message ...
ludovic mirabel wrote:
chung wrote in message ...
Bob Marcus wrote:
(ludovic mirabel) wrote in message news:%wV4b.329114$o%2.151942@sccrnsc02...
See discussion below:

Mirabel:
Shall I say what other test method is not like listening to music?
Chung:
With DBT, you can listen to music the way you normally audition
equipment at a store, i.e., listen for differences in normal
reproduction. Plus, DBT exercises the equipment the way they are meant
to be used. Huge improvements over yours.

At least on paper.
So using left-right I prefer one component even though I can not
judge imaging, crosstalk, minute residual speaker imbalances,
(inaudible after careful equalisation with my two digital equalisers)
etc. (Of course you have also telepathic vision concerning my
preamp's custom level controls deficiences).
If I tell you that the center image does not move you're free to
believe me or not. If I tell you that next I put my preferred
component in both channels and return for refund if horrible things
happen to imaging, crosstalk, power what not you may say it is not
research.
No it is not. It is just a modest home-practical way of avoiding
the nightmare of sighted bias that I read about in RAHE every day.
That's all. It does not replace experienced listening to a variety of
good recordings and it adds nothing to it. (I discover nothing
"subtle" that I do not hear otherwise)
Now let's see what you have on offer for a $ 600:00 switch. It
ought to be a huge improvement with all the the loving speculative
theory you lavish on it.
I must come now to the boring part. You heard it so many times
before- in fact it gives you headache. You may have even answered it
and I missed it but just this one time repeat it- if only for such as
All Ears waiting for the Voice of the Science to speak out.
It so happens that ALL the available published audiophile panel
ABX component comparisons had one outcome and one only: "They all
sound the same". All: cables, preamps, amps, cdplayers, dacs. Now Mr.
All Ears has 3 choices:
1) Everything in audio really does sound the same (unless it
measures grossly diferently eg. Wattage etc). Of course many think
that if you believe this nonsense you'll believe anything.
Or: 2) There is something the matter with the "great
improvement" which makes it useless for a cross- section of
audiophiles component comparison test.(Research is another matter
entirely)
3) Buy the switch and sign up for PC courses. But what if
you're one of the hopeless ABXers (ask the researchers about them?)
How will you know if you are hopeless or if everything really sounds
the same?
Ludovic Mirabel
P.S. Next, if the "great improvement" does not pan out tell us about
concentrating on the speakers- but how do you know that if you ABXed
good full range speakers with a listener panel they wouldn't sound the
same to most of them too?
Room improvement? If you had my room you'd know that selling the
house would be the only remedy. I tried wall fibreglass pads,
bookshelves located strategically, bags in the corner and all that. I
heard much, much less difference than between the silver cable a la
Kimber and the zipcord.

Previous text: (if you lasted this far)
Especially if you're using pink noise that some of your colleagues
(perhaps not you, in which case I apologise) claim is the best testing
signal for that other well-publicised "test".
The rest of your post snipped, due to repetition of previously posted
material.

On the whole if this is all you can criticise a reader might take it
as a recommendation.

Huh? That is all I can criticize? Have you read carefully? Have you
skipped the other "concerns" posted here? In fact, I have not found one
thing about your method that is an improvement over DBT.

By the way- did you try it?

No, and certainly no plans to, given these huge deficiencies of your method.


Ludovic Mirabel

Hi Ludovic

I too have tried some of the modes of testing you suggest. Having found them
being suggested in a different forum.

I used it on some speaker cables in purely subjective tests, using no meters
scopes or gauges of any sort.
As we all know by now (having been told SO MANY TIMES)
that copper is copper and all differences are at least 140db below 10V or
10Amps ,non linear non proportional.

When using different wires for Left and Right speakers in mono mode I of
course did NOT hear and tonal difference or change in the noise floor, and
in stereo i did NOT hear the sound image wander about the sound stage, the
depth of the stereo image was NOT grossly distorted, and these effect were
NOT highly frequency(note) dependant.
It is NOT a method for determining any differences in any part on the signal
chain, most definitely not revealing any difference in amplifiers. You
canNOT easily isolate or nullify the variations of the room effects /
speaker placing by swapping the left and right wires.

But as these tests were done on AB basis but weren't done DBT all of the
above results are of course NOT valid.



"ludovic mirabel" wrote in message
news:7dn8b.425040$o%2.192669@sccrnsc02...
chung wrote in message
. net...
ludovic mirabel wrote:
chung wrote in message
...
ludovic mirabel wrote:
chung wrote in message
...
Bob Marcus wrote:
(ludovic mirabel) wrote in message
news:%wV4b.329114$o%2.151942@sccrnsc02...
See discussion below:

Mirabel:
Shall I say what other test method is not like listening to music?
Chung:
With DBT, you can listen to music the way you normally audition
equipment at a store, i.e., listen for differences in normal
reproduction. Plus, DBT exercises the equipment the way they are meant
to be used. Huge improvements over yours.

At least on paper.
So using left-right I prefer one component even though I can not
judge imaging, crosstalk, minute residual speaker imbalances,
(inaudible after careful equalisation with my two digital equalisers)
etc. (Of course you have also telepathic vision concerning my
preamp's custom level controls deficiences).
If I tell you that the center image does not move you're free to
believe me or not. If I tell you that next I put my preferred
component in both channels and return for refund if horrible things
happen to imaging, crosstalk, power what not you may say it is not
research.
No it is not. It is just a modest home-practical way of avoiding
the nightmare of sighted bias that I read about in RAHE every day.
That's all. It does not replace experienced listening to a variety of
good recordings and it adds nothing to it. (I discover nothing
"subtle" that I do not hear otherwise)
Now let's see what you have on offer for a $ 600:00 switch. It
ought to be a huge improvement with all the the loving speculative
theory you lavish on it.
I must come now to the boring part. You heard it so many times
before- in fact it gives you headache. You may have even answered it
and I missed it but just this one time repeat it- if only for such as
All Ears waiting for the Voice of the Science to speak out.
It so happens that ALL the available published audiophile panel
ABX component comparisons had one outcome and one only: "They all
sound the same". All: cables, preamps, amps, cdplayers, dacs. Now Mr.
All Ears has 3 choices:
1) Everything in audio really does sound the same (unless it
measures grossly diferently eg. Wattage etc). Of course many think
that if you believe this nonsense you'll believe anything.
Or: 2) There is something the matter with the "great
improvement" which makes it useless for a cross- section of
audiophiles component comparison test.(Research is another matter
entirely)
3) Buy the switch and sign up for PC courses. But what if
you're one of the hopeless ABXers (ask the researchers about them?)
How will you know if you are hopeless or if everything really sounds
the same?
Ludovic Mirabel
P.S. Next, if the "great improvement" does not pan out tell us about
concentrating on the speakers- but how do you know that if you ABXed
good full range speakers with a listener panel they wouldn't sound the
same to most of them too?
Room improvement? If you had my room you'd know that selling the
house would be the only remedy. I tried wall fibreglass pads,
bookshelves located strategically, bags in the corner and all that. I
heard much, much less difference than between the silver cable a la
Kimber and the zipcord.

Previous text: (if you lasted this far)
Especially if you're using pink noise that some of your colleagues
(perhaps not you, in which case I apologise) claim is the best testing
signal for that other well-publicised "test".
The rest of your post snipped, due to repetition of previously posted
material.

On the whole if this is all you can criticise a reader might take it
as a recommendation.

Huh? That is all I can criticize? Have you read carefully? Have you
skipped the other "concerns" posted here? In fact, I have not found one
thing about your method that is an improvement over DBT.

By the way- did you try it?

No, and certainly no plans to, given these huge deficiencies of your
method.


Ludovic Mirabel

"chris" wrote in message ...
Hi Ludovic

I too have tried some of the modes of testing you suggest. Having found them
being suggested in a different forum.

I used it on some speaker cables in purely subjective tests, using no meters
scopes or gauges of any sort.
As we all know by now (having been told SO MANY TIMES)
that copper is copper and all differences are at least 140db below 10V or
10Amps ,non linear non proportional.

When using different wires for Left and Right speakers in mono mode I of
course did NOT hear and tonal difference or change in the noise floor, and
in stereo i did NOT hear the sound image wander about the sound stage, the
depth of the stereo image was NOT grossly distorted, and these effect were
NOT highly frequency(note) dependant.
It is NOT a method for determining any differences in any part on the signal
chain, most definitely not revealing any difference in amplifiers. You
canNOT easily isolate or nullify the variations of the room effects /
speaker placing by swapping the left and right wires.

You do "nullify and isolate" the room/speaker effects VERY
EASILY if you random- swap your component be it the amp, OR the
interconnects from one side of the system to the other. If you still
prefer, blind, one amp or one type of interconnects whichever side of
the room they are on you "nullified and isolated" the room/speaker
effects.
This seems to me so obvious that I suspect that you did not
follow the swapping protocol as outlined below. If you don't swap
you're wasting your time.

But as these tests were done on AB basis but weren't done DBT all of the
above results are of course NOT valid.

The "double blind" technique was a necessary forward step in medical
drug research so that the researcher did not impart his enthusiasm to
the patient.
If your helper is your wife who couldn't care less, single blind is
good enough. There is no need to slavishly imitate methods designed
for completely different tasks just to get the reflected glory of the
prestigious name.
And using the name does NOT automatically confer validity.
Thanks for your interest. Ludovic Mirabel

"ludovic mirabel" wrote in message
news:7dn8b.425040$o%2.192669@sccrnsc02...
chung wrote in message
. net...
ludovic mirabel wrote:
chung wrote in message
...
ludovic mirabel wrote:
chung wrote in message
...
Bob Marcus wrote:
(ludovic mirabel) wrote in message
news:%wV4b.329114$o%2.151942@sccrnsc02...
See discussion below:

Mirabel:
Shall I say what other test method is not like listening to music?
Chung:
With DBT, you can listen to music the way you normally audition
equipment at a store, i.e., listen for differences in normal
reproduction. Plus, DBT exercises the equipment the way they are meant
to be used. Huge improvements over yours.

At least on paper.
So using left-right I prefer one component even though I can not
judge imaging, crosstalk, minute residual speaker imbalances,
(inaudible after careful equalisation with my two digital equalisers)
etc. (Of course you have also telepathic vision concerning my
preamp's custom level controls deficiences).
If I tell you that the center image does not move you're free to
believe me or not. If I tell you that next I put my preferred
component in both channels and return for refund if horrible things
happen to imaging, crosstalk, power what not you may say it is not
research.
No it is not. It is just a modest home-practical way of avoiding
the nightmare of sighted bias that I read about in RAHE every day.
That's all. It does not replace experienced listening to a variety of
good recordings and it adds nothing to it. (I discover nothing
"subtle" that I do not hear otherwise)
Now let's see what you have on offer for a $ 600:00 switch. It
ought to be a huge improvement with all the the loving speculative
theory you lavish on it.
I must come now to the boring part. You heard it so many times
before- in fact it gives you headache. You may have even answered it
and I missed it but just this one time repeat it- if only for such as
All Ears waiting for the Voice of the Science to speak out.
It so happens that ALL the available published audiophile panel
ABX component comparisons had one outcome and one only: "They all
sound the same". All: cables, preamps, amps, cdplayers, dacs. Now Mr.
All Ears has 3 choices:
1) Everything in audio really does sound the same (unless it
measures grossly diferently eg. Wattage etc). Of course many think
that if you believe this nonsense you'll believe anything.
Or: 2) There is something the matter with the "great
improvement" which makes it useless for a cross- section of
audiophiles component comparison test.(Research is another matter
entirely)
3) Buy the switch and sign up for PC courses. But what if
you're one of the hopeless ABXers (ask the researchers about them?)
How will you know if you are hopeless or if everything really sounds
the same?
Ludovic Mirabel
P.S. Next, if the "great improvement" does not pan out tell us about
concentrating on the speakers- but how do you know that if you ABXed
good full range speakers with a listener panel they wouldn't sound the
same to most of them too?
Room improvement? If you had my room you'd know that selling the
house would be the only remedy. I tried wall fibreglass pads,
bookshelves located strategically, bags in the corner and all that. I
heard much, much less difference than between the silver cable a la
Kimber and the zipcord.

Previous text: (if you lasted this far)
Especially if you're using pink noise that some of your colleagues
(perhaps not you, in which case I apologise) claim is the best testing
signal for that other well-publicised "test".
The rest of your post snipped, due to repetition of previously posted
material.

On the whole if this is all you can criticise a reader might take it
as a recommendation.

Huh? That is all I can criticize? Have you read carefully? Have you
skipped the other "concerns" posted here? In fact, I have not found one
thing about your method that is an improvement over DBT.

By the way- did you try it?

No, and certainly no plans to, given these huge deficiencies of your
method.


Ludovic Mirabel