Archived from groups: rec.audio.tech (More info?)

Greetings,
 
I don't usually post here, but I noted the recent discussion of the
Stereo Review cable test of 1983. Much of what's been said about that
article has been in error. If anyone would like a copy of the article,
e-mail me privately. (Disclaimer: This offer may be withdrawn at any
time, especially if I get an overwhelming number of requests.)
 
Greenhill conducted double-blind ABX tests, using 30-foot lengths of
three different cables:
1) generic 24 AWG zip cord
2) generic 16 AWG zip cord
3) Monster brand 14 AWG cable
 
Greenhill did 6 tests in all, each comparing two of the above, under
various conditions. There were 11 subjects, each doing 15 trials for
each test, for a total of 165 trials per test. (A couple of tests had
slightly fewer trials.)
 
Of the six tests, two were very easy, and the panel basically scored
100%. Three other tests were difficult but doable, and the panel scored
about 67% on each. The significance level was about 60%, so these tests
were positive. The sixth test was impossible, and the panel scored just
under 50%.
 
As to the subject Greenhill labeled a "golden ear," you cannot add
up the scores that a single subject got on the six different tests and
get a meaningful number. That would be like adding your second-grade
spelling test to your SAT score. So the statement that somebody got 76
out of 90 correct overall is meaningless.
 
What distinguished "Golden Ear" was that he was the only panelist
to get a positive result on all three of the difficult-but-possible
tests. That's a fairly impressive performance, though not an
astounding one. Two or three other subjects got positive results on
each of those tests, and "Golden Ear" was not the top scorer on any
of them. In short, while he was consistently good, he did not hear
anything that no one else heard.
 
But none of those three tests are of much relevance to audiophile
interests. Two of them involved a comparison with 24-gauge cable, which
no self-respecting audiophile would use in 30-foot lengths. In the
third, the subjects were listening to pink noise, not music.
 
The only test that was really relevant to the high-end cable debate was
the comparison of the generic 16-gauge and the Monster cable, when the
subjects were listening to choral music. In that test, no subject got a
positive result, and the panel as a whole scored just under 50%. The
highest individual score was 11/15. (12/15 was significant.) "Golden
Ear" scored 10/15. There were just as many low scores as high ones,
exactly as you'd expect if everyone was just guessing.
 
Greenhill's conclusion: "So what do our fifty hours of testing,
scoring, comparing, and listening to speaker cables amount to? Only
that 16-gauge lamp cord and Monster Cable are indistinguishable from
each other with music and seem to be superior to the 24-gauge wire
commonly sold or given away as "speaker cable." . . . This project
was unable to validate the sonic benefits claimed for exotic speaker
cable over common 16-gauge zip cord. We can only conclude, therefore,
that there is little advantage besides pride of ownership in using
these thick, expensive wires."
 
bob

Archived from groups: rec.audio.tech (More info?)

What a relief :-)
Thank you.
 
--  
========================================================================
Martin Schöön                              <Martin.Schoon@gmail.com>
 
                                     "Problems worthy of attack
                                      prove their worth by hitting back"
                                                              Piet Hein
========================================================================

Archived from groups: rec.audio.tech (More info?)

Bob,
 
> If anyone would like a copy of the article <
 
Awesome, thanks, I just sent you an email.
 
--Ethan

Archived from groups: rec.audio.tech (More info?)

On 1 Sep 2005 08:53:44 -0700, bob wrote:
 
> Greetings,
>  
> I don't usually post here, but I noted the recent discussion of the
> Stereo Review cable test of 1983. Much of what's been said about that
> article has been in error. If anyone would like a copy of the article,
> e-mail me privately. (Disclaimer: This offer may be withdrawn at any
> time, especially if I get an overwhelming number of requests.)
>  
> Greenhill conducted double-blind ABX tests, using 30-foot lengths of
> three different cables:
> 1) generic 24 AWG zip cord
> 2) generic 16 AWG zip cord
> 3) Monster brand 14 AWG cable
>  
> Greenhill did 6 tests in all, each comparing two of the above, under
> various conditions. There were 11 subjects, each doing 15 trials for
> each test, for a total of 165 trials per test. (A couple of tests had
> slightly fewer trials.)
>  
> Of the six tests, two were very easy, and the panel basically scored
> 100%. Three other tests were difficult but doable, and the panel scored
> about 67% on each. The significance level was about 60%, so these tests
> were positive. The sixth test was impossible, and the panel scored just
> under 50%.
>  
> As to the subject Greenhill labeled a "golden ear," you cannot add
> up the scores that a single subject got on the six different tests and
> get a meaningful number. That would be like adding your second-grade
> spelling test to your SAT score. So the statement that somebody got 76
> out of 90 correct overall is meaningless.
>  
> What distinguished "Golden Ear" was that he was the only panelist
> to get a positive result on all three of the difficult-but-possible
> tests. That's a fairly impressive performance, though not an
> astounding one. Two or three other subjects got positive results on
> each of those tests, and "Golden Ear" was not the top scorer on any
> of them. In short, while he was consistently good, he did not hear
> anything that no one else heard.
>  
> But none of those three tests are of much relevance to audiophile
> interests. Two of them involved a comparison with 24-gauge cable, which
> no self-respecting audiophile would use in 30-foot lengths. In the
> third, the subjects were listening to pink noise, not music.
>  
> The only test that was really relevant to the high-end cable debate was
> the comparison of the generic 16-gauge and the Monster cable, when the
> subjects were listening to choral music. In that test, no subject got a
> positive result, and the panel as a whole scored just under 50%. The
> highest individual score was 11/15. (12/15 was significant.) "Golden
> Ear" scored 10/15. There were just as many low scores as high ones,
> exactly as you'd expect if everyone was just guessing.
>  
> Greenhill's conclusion: "So what do our fifty hours of testing,
> scoring, comparing, and listening to speaker cables amount to? Only
> that 16-gauge lamp cord and Monster Cable are indistinguishable from
> each other with music and seem to be superior to the 24-gauge wire
> commonly sold or given away as "speaker cable." . . . This project
> was unable to validate the sonic benefits claimed for exotic speaker
> cable over common 16-gauge zip cord. We can only conclude, therefore,
> that there is little advantage besides pride of ownership in using
> these thick, expensive wires."
>  
> bob
 
Pretty much what we all expected then. Competent cable is as good as exotic
cable. 30 feet of 24 gauge is a poor choice for speakers.
 
What does surprise me rather is that no subject got a "significant" score
on the 16 gauge test. Coin flipping should have yielded one.
 
d

Archived from groups: rec.audio.tech (More info?)

Don Pearce wrote:
>
> Pretty much what we all expected then. Competent cable is as good as exotic
> cable. 30 feet of 24 gauge is a poor choice for speakers.
>
> What does surprise me rather is that no subject got a "significant" score
> on the 16 gauge test. Coin flipping should have yielded one.
 
The chance of someone getting 12/15 is about 1.76%. The chance of one
of 11 people getting 12/15 is therefore about 18%. So coin flipping
would have been unlikely to produce a lucky winner in this case.
 
bob

Archived from groups: rec.audio.tech (More info?)

On 2 Sep 2005 14:52:13 -0700, bob wrote:
 
> Don Pearce wrote:
>>
>> Pretty much what we all expected then. Competent cable is as good as exotic
>> cable. 30 feet of 24 gauge is a poor choice for speakers.
>>
>> What does surprise me rather is that no subject got a "significant" score
>> on the 16 gauge test. Coin flipping should have yielded one.
>  
> The chance of someone getting 12/15 is about 1.76%. The chance of one
> of 11 people getting 12/15 is therefore about 18%. So coin flipping
> would have been unlikely to produce a lucky winner in this case.
>  
> bob
 
Exaxtly - and that is pretty good odds.
 
d