setting up ABX tests at home

Re: setting up ABX tests at home

On Feb 15, 6:43 pm, bear <bearl...@netzero,net > wrote:
> bob wrote:
> > On Feb 11, 7:17 pm, bear <bearl...@netzero,net > wrote:
>
> >> 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.
>
> > Please provide a citation for this research. Thanks.
>
> > bob
>
> Try Google? He has his own website.
> Dr. Earl Geddes.
> JAES articles, if you wish to buy them too.

A search of the JAES archive reveals 18 articles by Earl Geddes. All
18 are about loudspeakers. Not one is about amplifiers. So unless you
can supply us with one article about amplifier distortion, you might
want to stop making claims about what Earl Geddes has allegedly
written.

bob

Re: setting up ABX tests at home

Well we ABX my Squeezebox and my Arcam Alpha 7SE CD. We burned a CD
for the Arcam and defined a playlist for the SB and played them
together in sync (manually). As we didn't have the machinery we didn't
match the volume but put the switch down when switching and then back
up again after the switch until tester was happy.

Not very scientific I know but my aims were simple - was I able to
hear a difference between the two on my mid end home system - and the
conclusion was no!

In my searches over the internet I found a link to a spanish site
which is very interesting - I am sure Arny will love it!

http :// babelfish.altavista,com /babelfish/trurl pagecontent?lp=es en&url= http :// www .matrixhifi,com /pruebasciegas.htm

Re: setting up ABX tests at home

"Steve" <goldstarsteve@gmail,com > wrote in message
news:fpd6os025np@news4.newsguy,com ...
> http :// babelfish.altavista,com /babelfish/trurl_pagecontent?lp=es_en&url= http :// www .matrixhifi,com /pruebasciegas.htm

Excellent. My favourite line:

"YES WERE DIFFERENCES OF SOUND between the Discman and Audionote,
although very subtle and confirming all the group that sounded better
the Discman." :-)

Re: setting up ABX tests at home

"josko" <brakus@simon.rochester.edu> wrote in message
news:fpg33c02281@news3.newsguy,com ...
> "Steve" <goldstarsteve@gmail,com > wrote in message
> news:fpd6os025np@news4.newsguy,com ...
>> http :// babelfish.altavista,com /babelfish/trurl_pagecontent?lp=es_en&url= http :// www .matrixhifi,com /pruebasciegas.htm
>
> Excellent. My favourite line:
>
> "YES WERE DIFFERENCES OF SOUND between the Discman and Audionote,
> although very subtle and confirming all the group that sounded better
> the Discman." :-)

But please don't forget an example of a portable CD player sounded better
than did some very serious models.
http :// www .stereophile,com /cdplayers/480/

Re: setting up ABX tests at home

"bear" <bearlabs@netzero,net > wrote in message
news:foqoi402tkd@news1.newsguy,com
> Arny Krueger wrote:
>> "Greg Wormald" <greg.wormald@gmail,com > wrote in message
>> news:folrst02p34@news1.newsguy,com

>>> 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...?

ABX tests involve listening, listening is how we get subjective enjoyment.
Why shouldn't ABX tests correlate with subjective enjoyment?

> The ABX is intended and designed to merely yield data
> about audible differences between two variables - nothing
> more.

Do you think that subjective enjoyment from listening to music comes from
some source other than audible features of the music being listened to?

> IF it accomplishes that goal is yet not clear and
> unproven beyond the specific test that took place.

Seems like some words are missing from that sentence.

> In other words the results of specific ABX tests can not be generalized to
> pertain to every situation.

Of course this is a truism. But how does an ABX test vary in this regard
from any other listening experience?

> While the results *might* be useful or of general use, it is not an
> inherent quality
> of an "ABX" test.

This is true of any listening experience. I hope you are not against the use
of listening experiences to evaluate audio products! ;-)

> The reasons - as have been debated here many times - are
> multiple.

If an issue has been debated without resolution, then it cannot be used to
resolve a controversy.

>> 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 support 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.

So far I am aware of no compelling arguments, no compelling evidence that
suggests otherwise.

> It is not fully supported by any factual basis.

I know of no facts that contradict it.

>>> 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.

Do tell!

> 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.

Again that is a position that is at best a subject of unresolved debate. If
an issue has been debated without resolution, then it cannot be used to
resolve a controversy.

> Let me list a few for the readers:

> - frequency response of the speakers

Why must this be an unknown variable, and why would it be a known variabile
in a sighted evaluation, but not known when the evaluation is done blind?

> - distortion vs. power vs. frequency for the speakers

ditto.

> - polar response of the speakers vs. frequency

ditto.

> - reverberation time vs. frequency of the room
> etc. etc. etc....

ditto, ditto, ditto.

You see, this is a common mistake. You've raised issues that relate
identically to blind and sighted evaluations.

> 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.

I know of no published ABX tests that are secret. AFAIK whatever information
you might relate to duplicating a test, can be obtained from the people who
performed the tests.

> Show me *one* that has the requisite information and
> controls.

Show me a sighted, non-level-matched, non-time-synched evaluation that has
the requisite information and controls.

Show me an evaluation whose details are published in a high end audio
publication that has the requisite information and controls.

> 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.

Geddes is an advocate of the same kinds of listening tests as you are
criticizing. Why would you use his tests or conclusions as being
authoritative?

You might be interested to know that three of the ABX partners including
myself and David Clark of AES fame attended a Chinese New Years party given
by Earl Geddes and his wife Lydia Lee at their home last Saturday night. Dr.
Geddes is a long time friend of ABX and other forms of blind testing, to say
the very least! ;-)

Re: setting up ABX tests at home

Arny Krueger wrote:
> "bear" <bearlabs@netzero,net > wrote in message
> news:foqoi402tkd@news1.newsguy,com
>> Arny Krueger wrote:
>>> "Greg Wormald" <greg.wormald@gmail,com > wrote in message
>>> news:folrst02p34@news1.newsguy,com
>
<snip>
Arny, you seem to have comingled my comments with another writer- I've snipped
that part...

>
>>> 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.
>
> So far I am aware of no compelling arguments, no compelling evidence that
> suggests otherwise.
>
>> It is not fully supported by any factual basis.
>
> I know of no facts that contradict it.
>
>>>> 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.
>
> Do tell!
>
>> 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.
>
> Again that is a position that is at best a subject of unresolved debate. If
> an issue has been debated without resolution, then it cannot be used to
> resolve a controversy.
>
>> Let me list a few for the readers:
>
>> - frequency response of the speakers
>
> Why must this be an unknown variable, and why would it be a known variabile
> in a sighted evaluation, but not known when the evaluation is done blind?

BECAUSE in order to do a SCIENTIFIC TEST:
- the test conditions must be known.
- the test's parameters must be known.
- the test must be replicable by independent researchers!
- controls must be in place.

This is basic, no?

>
>> - distortion vs. power vs. frequency for the speakers
>
> ditto.
>
>> - polar response of the speakers vs. frequency
>
> ditto.
>
>> - reverberation time vs. frequency of the room
>> etc. etc. etc....
>
> ditto, ditto, ditto.
>
> You see, this is a common mistake. You've raised issues that relate
> identically to blind and sighted evaluations.

So what?

I am saying (again and again) that ABX testing, while a useful tool, is not
dispositive of any issue whatsever, except to the extent that the conditions for
a test that uses a *true scientific method* is done AND those conditions clearly
do not have compromises built-in that skew or alter the results! Otherwise, the
tests, be they ABX or other means are only valid FOR THAT TEST (if valid at all).

>
>> 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.
>
> I know of no published ABX tests that are secret. AFAIK whatever information
> you might relate to duplicating a test, can be obtained from the people who
> performed the tests.
>
>> Show me *one* that has the requisite information and
>> controls.
>
> Show me a sighted, non-level-matched, non-time-synched evaluation that has
> the requisite information and controls.

Who cares?
YOU are claiming scientific method and certainty!
THEY are not!
The onus is upon those who claim science and certainty!

I am not supporting any method or any point of view in all this.
I am however pointing out the limitations of ABX to this date, since so many
seem to be claiming that ABX has resulted in certainty of result which can be
applied and generalized. It can not, in my view.

>
> Show me an evaluation whose details are published in a high end audio
> publication that has the requisite information and controls.
>
>> 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.
>
> Geddes is an advocate of the same kinds of listening tests as you are
> criticizing. Why would you use his tests or conclusions as being
> authoritative?

BECAUSE THEY POINT OUT WHY EXACTLY MANY OF THE ABX TESTS TO DATE HAVE A GAPING
HOLE IN THEIR METHOD!!!

Again, Arny, I know this is difficult to quite figure out but I do NOT have any
prejudice against ABX or *any other testing method*!!! I do have a problem with
claiming that one tool (ABX in this case) automatically has results that fully
define these issues (the ones we're talking about).

I'm 100% fine with Dr. Geddes results, since they EXPLAIN a whole lot about many
many discrepancies between the "low distortion" camp and the "tubes sound
better" camp - and why some "low distortion" amps and other gear sounds like
*ca-ca*.

Fwiw, Geddes is the second to get these results scientifically - he merely has
done it most recently, and more definitively.

HE HAS REDUCED THIS TO A USABLE PARAMETRIC TEST. <--- key point, eh??

>
> You might be interested to know that three of the ABX partners including
> myself and David Clark of AES fame attended a Chinese New Years party given
> by Earl Geddes and his wife Lydia Lee at their home last Saturday night. Dr.
> Geddes is a long time friend of ABX and other forms of blind testing, to say
> the very least! ;-)
>

So what?

You've got the wrong idea about this Arny.

Since ur his friend, perhaps you should ask him to explain that part of his
research to you - and mention that I suggested that to you? Which will be funny,
since I doubt that he thinks of me as being "in your camp" on these sorts of things.

Even so, his research is solid, his designs very sharp, and on this matter he
has inadvertently put a major bit of science into the hands of those who have
long claimed to subjectively note sonic differences (that have long been denied
by "objectivists")! So, I thank him for reducing to practice what I have long
held without adequate means to test or otherwise prove!!

Whether or not his speakers sound any good, or I would like them, is another
matter...! : )

- -bear

Re: setting up ABX tests at home

"bear" <bearlabs@netzero,net > wrote in message
news:fp588l01ah1@news1.newsguy,com

> BECAUSE in order to do a SCIENTIFIC TEST:
> - the test conditions must be known.

That disqualifies every sighted evaluation because the test conditions are
not as well known as they can be if blind testing procedures are used.

> - the test's parameters must be known.

Redundant with point one. Test conditions are the same as test parameters.

> - the test must be replicable by independent researchers!

That eliminates any subjective evaluation because the subject is an inherent
part of a subjective evaluation and every subject, being a human being is
unique. You can't replicate the test independently, because doing a test
independently eliminates the possibility using the same subject.

> - controls must be in place.

Redundant with point one. Controls are same thing as test parameters.

> This is basic, no?

If you can live with the caveats above, so can I. ;-)

>> You see, this is a common mistake. You've raised issues
>> that relate identically to blind and sighted evaluations.

> So what?

So your elimination of sighted tests from your critiques invalidates the
critiques themselves.

> I am saying (again and again) that ABX testing, while a
> useful tool, is not dispositive of any issue whatsever,
> except to the extent that the conditions for a test that uses a *true
> scientific method* is done AND
> those conditions clearly

You just made the same mistake all over again. You've raised issues
that relate identically to blind and sighted evaluations, but did not
include sighted evaluations in your discussion.

>>> 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.

>> I know of no published ABX tests that are secret. AFAIK
>> whatever information you might relate to duplicating a
>> test, can be obtained from the people who performed the
>> tests.

>>> Show me *one* that has the requisite information and
>>> controls.

>> Show me a sighted, non-level-matched, non-time-synched
>> evaluation that has the requisite information and
>> controls.

> Who cares?

If you don't care about the outcomes of sighted evaluations, that is fine
with me.

> YOU are claiming scientific method and certainty!

Actually, using the scientific method eliminates claiming certainty. The
outcome of any scientific investigation is not certain but merely
provisional, until more relevant results are obtained. In just my short 61
years I've seen all kinds of non-trival scientific investigations in just
about every major area of endeover invalidated by more relevant results.

> THEY are not!

To use a popular phrase, who cares? ;-)

> The onus is upon those who claim science and certainty!

"Science and certainty" is an invalid phrase for the reasons just given.

> I am not supporting any method or any point of view in
> all this.

Then why all these mentions of ABX, and not listening tests in general?

> I am however pointing out the limitations of ABX to this
> date, since so many seem to be claiming that ABX has resulted in certainty
> of
> result which can be applied and generalized.

I would hope that one and all would use, if nothing else, my humble words
above to dissuade one and all from believing that the results of ABX tests
are certain.

> It can not, in my view.

That is a truism. I stipulate that it is true.

>> Show me an evaluation whose details are published in a
>> high end audio publication that has the requisite
>> information and controls.

<no response to a simple request.>

>>> 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.

>> Geddes is an advocate of the same kinds of listening
>> tests as you are criticizing. Why would you use his
>> tests or conclusions as being authoritative?

> BECAUSE THEY POINT OUT WHY EXACTLY MANY OF THE ABX TESTS
> TO DATE HAVE A GAPING > HOLE IN THEIR METHOD!!!

That is also a truism. I stipulate that it is true.

> Again, Arny, I know this is difficult to quite figure out
> but I do NOT have any prejudice against ABX or *any other
> testing method*!!!

It appears that we are training you to not pick on just ABX tests for having
a common flaw that besets all tests, and probably many of those other tests
even worse than ABX.

> I do have a problem with claiming that
> one tool (ABX in this case) automatically has results
> that fully define these issues (the ones we're talking
> about).

I don't anybody making that claim. For example, like many others including
Mr. Sullivant, for years I've been mentioning ABX/hr as being superior to
ABX for many kinds of subjective testing.

> I'm 100% fine with Dr. Geddes results, since they EXPLAIN
> a whole lot about many many discrepancies between the
> "low distortion" camp and the "tubes sound better" camp - and why some
> "low distortion" amps and
> other gear sounds like *ca-ca*.

I don't think so. If you talk to Geddes and read his papers, the major focus
of his work is loudspeakers, not amplifiers at all. I know for a fact that
Geddes personal audio systems use inexpensive receivers as their amplifiers.
Pioneer, Yamaha, Sony consumer line, and stuff like that.

>>
>> You might be interested to know that three of the ABX
>> partners including myself and David Clark of AES fame
>> attended a Chinese New Years party given by Earl Geddes
>> and his wife Lydia Lee at their home last Saturday
>> night. Dr. Geddes is a long time friend of ABX and other
>> forms of blind testing, to say the very least! ;-)

> So what?

The point is that you can't use Geddes test for the purpose that you have
been using it.

> You've got the wrong idea about this Arny.

Show me!

> Since ur his friend, perhaps you should ask him to
> explain that part of his research to you - and mention
> that I suggested that to you? Which will be funny, since
> I doubt that he thinks of me as being "in your camp" on
> these sorts of things.

It's not my camp or his camp, it is our camp. ;-)

> Even so, his research is solid, his designs very sharp,
> and on this matter he has inadvertently put a major bit of science into
> the
> hands of those who have long claimed to subjectively note sonic
> differences (that
> have long been denied by "objectivists")!

No such thing.

> So, I thank him for reducing to
> practice what I have long held without adequate means to test or otherwise
> prove!!

It would appear that there is quite a discrepancy between how you perceve
Geddes' work and how he does.

> Whether or not his speakers sound any good, or I would
> like them, is another matter...! :_)

His speakers are basically very nice high efficiency 2-way speakers with a
15" woofer and a horn tweeter, that are very similar in many ways to EV
ZX-5 professional audio speakers. Since his speakers are designed to have
somewhat deeper bass, the enclosures are larger. Since the speaker is not
designed for the highest possible SPLs, the crossover to the tweeter is at a
lower frequency. I believe that the horn for the tweeter is one of his
proprietary designs and uses an partially absorbant plug to reduce
reflections in the horn.

Re: setting up ABX tests at home

Arny Krueger wrote:
> "bear" <bearlabs@netzero,net > wrote in message
> news:fp588l01ah1@news1.newsguy,com
>
>> BECAUSE in order to do a SCIENTIFIC TEST:
>> - the test conditions must be known.
>
> That disqualifies every sighted evaluation because the test conditions are
> not as well known as they can be if blind testing procedures are used.

Don't care one way or the other.
I'm not here to defend sighted evaluations in terms of scientific or engineering
principles.

>
>> - the test's parameters must be known.
>
> Redundant with point one. Test conditions are the same as test parameters.

Only if they are reduced to a parametric quantity or other condition that can be
replicated!

>
>> - the test must be replicable by independent researchers!
>
> That eliminates any subjective evaluation because the subject is an inherent
> part of a subjective evaluation and every subject, being a human being is
> unique. You can't replicate the test independently, because doing a test
> independently eliminates the possibility using the same subject.

Nonsense.
The *test* meaning the acoustic and electronic conditions Arny.
Silly of you to think that! : )

>
>> - controls must be in place.
>
> Redundant with point one. Controls are same thing as test parameters.
>
>> This is basic, no?
>
> If you can live with the caveats above, so can I. ;-)

Sure, as long as you understand that these sorts of issues remain uncontrolled
thus far in all tests that I am aware of.

>
>>> You see, this is a common mistake. You've raised issues
>>> that relate identically to blind and sighted evaluations.
>
>> So what?
>
> So your elimination of sighted tests from your critiques invalidates the
> critiques themselves.

Huh?

Apples and oranges, Arny.
We're discussing your style of testing only.

>
>> I am saying (again and again) that ABX testing, while a
>> useful tool, is not dispositive of any issue whatsever,
>> except to the extent that the conditions for a test that uses a *true
>> scientific method* is done AND
>> those conditions clearly
>
> You just made the same mistake all over again. You've raised issues
> that relate identically to blind and sighted evaluations, but did not
> include sighted evaluations in your discussion.

Why should they be?
You discard them completely no matter what.
So, let's ignore them.
Concentrate on why ABX testing has flaws, and so those results can not be
reliably generalized beyond the specific tests??

>
>>>> 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.
>
>>> I know of no published ABX tests that are secret. AFAIK
>>> whatever information you might relate to duplicating a
>>> test, can be obtained from the people who performed the
>>> tests.
>
>>>> Show me *one* that has the requisite information and
>>>> controls.
>
>>> Show me a sighted, non-level-matched, non-time-synched
>>> evaluation that has the requisite information and
>>> controls.
>
>> Who cares?
>
> If you don't care about the outcomes of sighted evaluations, that is fine
> with me.

No I don't actually.
Don't care about the outcomes of blind tests either as they now stand, with one
notable exception - already noted.

>
>> YOU are claiming scientific method and certainty!
>
> Actually, using the scientific method eliminates claiming certainty. The
> outcome of any scientific investigation is not certain but merely
> provisional, until more relevant results are obtained. In just my short 61
> years I've seen all kinds of non-trival scientific investigations in just
> about every major area of endeover invalidated by more relevant results.

Fine by me.
I have repeatedly noted some possible and plausible issues with the current
methods that I am aware of using ABX and similar testing...

>
>> THEY are not!
>
> To use a popular phrase, who cares? ;-)
>
>> The onus is upon those who claim science and certainty!
>
> "Science and certainty" is an invalid phrase for the reasons just given.

Yes, but Arny when you post you clearly imply that because of your "scientific
method" that your views are the only valid ones... or so it appears to this
reader...

>
>> I am not supporting any method or any point of view in
>> all this.
>
> Then why all these mentions of ABX, and not listening tests in general?

Because of your claims.

>
>> I am however pointing out the limitations of ABX to this
>> date, since so many seem to be claiming that ABX has resulted in certainty
>> of
>> result which can be applied and generalized.
>
> I would hope that one and all would use, if nothing else, my humble words
> above to dissuade one and all from believing that the results of ABX tests
> are certain.

Geez, I'd like to retain that as a quote for future use.

>
>> It can not, in my view.
>
> That is a truism. I stipulate that it is true.
>
>>> Show me an evaluation whose details are published in a
>>> high end audio publication that has the requisite
>>> information and controls.
>
> <no response to a simple request.>

Never claimed they were any good.
Why should I have to support those people?

>
>>>> 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.
>
>>> Geddes is an advocate of the same kinds of listening
>>> tests as you are criticizing. Why would you use his
>>> tests or conclusions as being authoritative?
>
>> BECAUSE THEY POINT OUT WHY EXACTLY MANY OF THE ABX TESTS
>> TO DATE HAVE A GAPING > HOLE IN THEIR METHOD!!!
>
> That is also a truism. I stipulate that it is true.
>
>> Again, Arny, I know this is difficult to quite figure out
>> but I do NOT have any prejudice against ABX or *any other
>> testing method*!!!
>
> It appears that we are training you to not pick on just ABX tests for having
> a common flaw that besets all tests, and probably many of those other tests
> even worse than ABX.

Nah, you're perhaps finally learning to listen/read what I write/wrote??

>
>> I do have a problem with claiming that
>> one tool (ABX in this case) automatically has results
>> that fully define these issues (the ones we're talking
>> about).
>
> I don't anybody making that claim. For example, like many others including
> Mr. Sullivant, for years I've been mentioning ABX/hr as being superior to
> ABX for many kinds of subjective testing.
>
>> I'm 100% fine with Dr. Geddes results, since they EXPLAIN
>> a whole lot about many many discrepancies between the
>> "low distortion" camp and the "tubes sound better" camp - and why some
>> "low distortion" amps and
>> other gear sounds like *ca-ca*.
>
> I don't think so. If you talk to Geddes and read his papers, the major focus
> of his work is loudspeakers, not amplifiers at all. I know for a fact that
> Geddes personal audio systems use inexpensive receivers as their amplifiers.
> Pioneer, Yamaha, Sony consumer line, and stuff like that.

yeah, I know. He's said as much.
But, iirc, he did some testing which included amplifiers using his "GedLee Metric".

>
>>> You might be interested to know that three of the ABX
>>> partners including myself and David Clark of AES fame
>>> attended a Chinese New Years party given by Earl Geddes
>>> and his wife Lydia Lee at their home last Saturday
>>> night. Dr. Geddes is a long time friend of ABX and other
>>> forms of blind testing, to say the very least! ;-)
>
>> So what?
>
> The point is that you can't use Geddes test for the purpose that you have
> been using it.

What?
His results clearly show something important that pertains to all sorts of
prejudices and presumptions about the audibility of distortions!!

>
>> You've got the wrong idea about this Arny.
>
> Show me!

Just did.

>
>> Since ur his friend, perhaps you should ask him to
>> explain that part of his research to you - and mention
>> that I suggested that to you? Which will be funny, since
>> I doubt that he thinks of me as being "in your camp" on
>> these sorts of things.
>
> It's not my camp or his camp, it is our camp. ;-)

Mmmm... to bad you've taken a dogmatic viewpoint.
I prefer to take a more even-handed and open-minded approach, while still
maintaining a good degree of healthy skepticism.

>
>> Even so, his research is solid, his designs very sharp,
>> and on this matter he has inadvertently put a major bit of science into
>> the
>> hands of those who have long claimed to subjectively note sonic
>> differences (that
>> have long been denied by "objectivists")!
>
> No such thing.

Funny. Then you fail to comprehend the significance of his GedLee Metric concept
at all! It shows that mere distortion figures do NOT correlate to audibility.

>
>> So, I thank him for reducing to
>> practice what I have long held without adequate means to test or otherwise
>> prove!!
>
> It would appear that there is quite a discrepancy between how you perceve
> Geddes' work and how he does.

Sure. No doubt. Apparently he doesn't see the ramifications the same way I do.
But it certainly applies as I have suggested.

>
>> Whether or not his speakers sound any good, or I would
>> like them, is another matter...! : )
>
> His speakers are basically very nice high efficiency 2-way speakers with a
> 15" woofer and a horn tweeter, that are very similar in many ways to EV
> ZX-5 professional audio speakers. Since his speakers are designed to have
> somewhat deeper bass, the enclosures are larger. Since the speaker is not
> designed for the highest possible SPLs, the crossover to the tweeter is at a
> lower frequency. I believe that the horn for the tweeter is one of his
> proprietary designs and uses an partially absorbant plug to reduce
> reflections in the horn.

Yes, I know.

>

The question is does it sound any good? ; )

- -bear

Re: setting up ABX tests at home

On Fri, 15 Feb 2008 15:46:29 -0800, bear wrote
(in article <fp588l01ah1@news1.newsguy,com >):

> Arny Krueger wrote:
>> "bear" <bearlabs@netzero,net > wrote in message
>> news:foqoi402tkd@news1.newsguy,com
>>> Arny Krueger wrote:
>>>> "Greg Wormald" <greg.wormald@gmail,com > wrote in message
>>>> news:folrst02p34@news1.newsguy,com
>>
> <snip>
> Arny, you seem to have comingled my comments with another writer- I've
> snipped
> that part...
>
>>
>>>> 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.
>>
>> So far I am aware of no compelling arguments, no compelling evidence that
>> suggests otherwise.
>>
>>> It is not fully supported by any factual basis.
>>
>> I know of no facts that contradict it.
>>
>>>>> 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.
>>
>> Do tell!
>>
>>> 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.
>>
>> Again that is a position that is at best a subject of unresolved debate. If
>> an issue has been debated without resolution, then it cannot be used to
>> resolve a controversy.
>>
>>> Let me list a few for the readers:
>>
>>> - frequency response of the speakers
>>
>> Why must this be an unknown variable, and why would it be a known variabile
>> in a sighted evaluation, but not known when the evaluation is done blind?
>
> BECAUSE in order to do a SCIENTIFIC TEST:
> - the test conditions must be known.
> - the test's parameters must be known.
> - the test must be replicable by independent researchers!
> - controls must be in place.
>
> This is basic, no?

It's also simple. Take any system, take one component in that system and
switch it for another of the same type and listen for differences. Test
conditions are known because the only thing changed from one component to the
next is the component under test. All else is the same for both.

Re: setting up ABX tests at home

Sonnova wrote:
> On Fri, 15 Feb 2008 15:46:29 -0800, bear wrote
> (in article <fp588l01ah1@news1.newsguy,com >):
.
>>
>> This is basic, no?
>
> It's also simple. Take any system, take one component in that system and
> switch it for another of the same type and listen for differences. Test
> conditions are known because the only thing changed from one component to the
> next is the component under test. All else is the same for both.

You fail to comprehend that if the system under test happens to have distortion
components that "mask" then the test is certainly valid for the system, but not
to any other system any place else.

You have possibly learned absolutely nothing about the components you think you
are testing.

Simple.

- -bear

Re: setting up ABX tests at home

On Sun, 17 Feb 2008 07:29:55 -0800, bear wrote
(in article <fp9jtj01hl6@news5.newsguy,com >):

> Sonnova wrote:
>> On Fri, 15 Feb 2008 15:46:29 -0800, bear wrote
>> (in article <fp588l01ah1@news1.newsguy,com >):
> .
>>>
>>> This is basic, no?
>>
>> It's also simple. Take any system, take one component in that system and
>> switch it for another of the same type and listen for differences. Test
>> conditions are known because the only thing changed from one component to
>> the
>> next is the component under test. All else is the same for both.
>
> You fail to comprehend that if the system under test happens to have
> distortion
> components that "mask" then the test is certainly valid for the system, but
> not
> to any other system any place else.
>
> You have possibly learned absolutely nothing about the components you think
> you
> are testing.
>
> Simple.

I understand what you are getting at now, finally. I concur.

Re: setting up ABX tests at home

"bear" <bearlabs@netzero,net > wrote in message
news:fp9jtj01hl6@news5.newsguy,com
> Sonnova wrote:
>> On Fri, 15 Feb 2008 15:46:29 -0800, bear wrote
>> (in article <fp588l01ah1@news1.newsguy,com >):
> .
>>>
>>> This is basic, no?
>>
>> It's also simple. Take any system, take one component in
>> that system and switch it for another of the same type
>> and listen for differences. Test conditions are known
>> because the only thing changed from one component to the
>> next is the component under test. All else is the same
>> for both.

> You fail to comprehend that if the system under test
> happens to have distortion components that "mask" then
> the test is certainly valid for the system, but not to
> any other system any place else.

In fact, the most common source of masking is the music itself. By that, I
mean the acoustical sounds that musical instruments make when a musician
plays them.

Re: setting up ABX tests at home

bear <bearlabs@netzero,net > wrote:
> Arny Krueger wrote:
> > "Greg Wormald" <greg.wormald@gmail,com > wrote in message
> > news:folrst02p34@news1.newsguy,com
> >
> >> 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...?

Preference presumes difference.

You might want to try an ABC/hr, a more common protocol for blind testing
of audio preference.

> 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 support 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 supported 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
> - distortion vs. power vs. frequency for the speakers
> - polar response of the speakers vs. frequency
> - reverberation time vs. frequency of the room
> 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.

> Show me *one* that has the requisite information and controls.

> 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.

Earl Geddes has also written
http :// www .gedlee,com /downloads/Chapter4.pdf

//
If one accepts the fact that subjective evaluations are less reliable than we would like, then it should
be obvious how objective measurements would play a crucial role in audio. Whatever one might say
about measurements, for the most part they are stable and yield the same results over and over.
something that subjective assessments have trouble doing. I used to believe that objective measurements
alone were all that one needed, and I still believe that objective measurements can tell us most
of what we need to know about a system or component. I believe that I could predict the judgement of
a panel of blind listeners with an accuracy of about 90-95% correct from objective data alone. I know
one company that claims a 99.9% accuracy in correlation between objective data and panel judgements.
Objective data should always be the place where one starts when looking for system components.
That is, if one knows how to interpret the measurements that are available or the data that they
are shown. I find that most people shy away from objective data simply because they don.t really understand
it.
As far as believing that objective data is all that we need, at the moment, that probably isn.t the
case. There are things that we are learning day-to-day that have a strong bearing on the correlation between
measurements and subjective preference. But that.s also not to say that we can.t ever get to the
point where objective data alone is sufficient. In fact this point may be closer than you think.

//

Sounds like he's a very strong proponent of objective measurements. I doubt he's really
as much on your 'side' of this argument as you think.

> So, the sum total of all this is that ABX is a tool that may or may not yield
> information that is useful. Period.

Onbly if you don't define 'useful'

___
-S
"Hey pip squeak, who's L Ron, some new rapper?" -- Nic

Re: setting up ABX tests at home

On Feb 9, 10:43 pm, Greg Wormald <greg.worm...@gmail,com > wrote:

> A goodly number of
> years ago I ABX blind tested some interconnects, and then chose the ones
> I preferred.

That's really amazing, since ABX isn't a preference test. Perhaps the
OP would do better to take advice on ABX tests from people who know
what they are.

bob

Re: setting up ABX tests at home

On Sat, 9 Feb 2008 19:43:25 -0800, Greg Wormald wrote
(in article <folrst02p34@news1.newsguy,com >):

> Steve wrote:
>> I want to set up an ABX test at home on different sources to see if I
>> can hear a difference. I am doing this for my own education and fun -
>> I don't want to start investing in SPL meters, switches gain
>> equalizers of other boxes.
>
> Steve,
>
> As long as you are doing it for fun, the set-ups you have specified
> should work. Education is a different matter.
>
> While ABX tests have their proponents, they also have detractors, and
> such tests may not educate you about equipment at all. What both
> proponents and detractors agree upon is that for short term tests
> absolute sound level matching is a must. Many tests have shown that the
> louder source is usually preferred.
>
> 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. 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.

I don't remember ever reading that there is any time limit imposed on
listening to one or the other DUT during a an ABX test. It's proponents are
usually quick to point that out. There is no reason why you can't listen to
one component for hours before switching.

Oh, yes. Cables differences are snake-oil. There is simply no phenomenon of
electronics, or music which would make one interconnect sound different from
another UNLESS it was purposely designed to have enough inductive and
capacitive reactance to act as a filter at audio frequencies - and who would
want cables that purposely caused frequency response anomalies?

> Good luck with your testing, I hope it is fun.
>
> Greg