I found someone to help me. We are starting tonight. I'm going to do
some training of my ears first. I would appreciate any suggestions
that people can give me for improving the test.

Here's the system: I'm connecting a Marantz CD player to a CAL DAC to
an Antique Sound Lab MG Head OTL Mk III headphone amplifier to AKG K501
headphones.

The cables to test will run between the DAC and the headphone
amplifier. They a

Rat Shack 2M gold-plated, about $5
Transparent 2M, the one without network boxes, about $75

Making it blind
------------------

I will hang a sheet over most of the system. I still need to access
the CD player to start and stop things and put them in and out. The CD
player is at the bottom of my rack, so I will tuck the sheet into the
component above it, blocking everything else from my view. I will make
sure that there is no way I can see the cables themselves, but I will
have to sit in front of the rack.

My friend will hook up cables following my instructions, either A, B or
X as I instruct. He will determine X with a coin toss and write it
down. I will leave the room, he will hook up the cable and call me
back into the room. We will need to have some interaction as he will
call me, and we will pass each other coming in and out of the room. I
will keep my eyes closed so at least I won't pick up any verbal clues.
Hey it occurs to me that I can have him knock on something instead of
calling me so I can't pick up on any voice cues.

Level matching
------------------

I don't have a good way to control levels.. I don't have a CD with a
test tone. Hmm, it occurs to me that I can burn one. I have a basic
voltmeter. Okay, I will do some basic measurements on a test tone. Is
a 1Khz test tone good? Also, it is a good assumption that two straight
wires into a 100K ohm load aren't going to differ by more than 0.1 dB?
But in any case I will leave the amplifier's volume control in one
position and not touch it during each trial.

Documentation
---------------

I type everything that happens in time order into my laptop and publish
it on the web.

Protocol
--------------

Basic ABX, but not with a switcher box-- instead I will ask my friend
to hook up one of the cables each time. This will take a while,
obviously, and I won't be able to do many auditions of each cable, nor
will I be able to switch quickly.

Also, if I get tired or confused, I will simply not give an answer for
the current trial, and start with that trial again later or another
day. Does that sound acceptable? It seems to me that there's a small
chance this could be a way to defeat the test; i.e. refuse to answer
when I'm not sure, implying that I'm only sure when I've picked up the
answer by non-sonic means. However, I will write down everything that
happens including the times that I refuse to answer so people can
review it later.

Training
---------------

For the initial tests, I will ask my friend whether I guessed right
after each trial. When I'm confident that I've learned well the sound
of each cable, then the "test proper" will start. I will determine a
number of trials and write down my answer after each trial, but not
compare answers to the answer sheet until the proper number of trials
has been reached.


-Mike

Michael Mossey wrote:
I found someone to help me. We are starting tonight. I'm going to
do
some training of my ears first. I would appreciate any suggestions
that people can give me for improving the test.

Here's the system: I'm connecting a Marantz CD player to a CAL DAC to
an Antique Sound Lab MG Head OTL Mk III headphone amplifier to AKG
K501
headphones.

Is that a tube amp? I'd want somebody to confirm that there aren't
impedance problems here that might create FR anomalies.

The cables to test will run between the DAC and the headphone
amplifier. They a

Rat Shack 2M gold-plated, about $5
Transparent 2M, the one without network boxes, about $75

Making it blind
------------------

I will hang a sheet over most of the system. I still need to access
the CD player to start and stop things and put them in and out. The
CD
player is at the bottom of my rack, so I will tuck the sheet into the
component above it, blocking everything else from my view. I will
make
sure that there is no way I can see the cables themselves, but I will
have to sit in front of the rack.

My friend will hook up cables following my instructions, either A, B
or
X as I instruct. He will determine X with a coin toss and write it
down. I will leave the room, he will hook up the cable and call me
back into the room. We will need to have some interaction as he will
call me, and we will pass each other coming in and out of the room.
I
will keep my eyes closed so at least I won't pick up any verbal
clues.
Hey it occurs to me that I can have him knock on something instead of
calling me so I can't pick up on any voice cues.

Level matching
------------------

I don't have a good way to control levels.. I don't have a CD with a
test tone. Hmm, it occurs to me that I can burn one. I have a basic
voltmeter. Okay, I will do some basic measurements on a test tone.
Is
a 1Khz test tone good? Also, it is a good assumption that two
straight
wires into a 100K ohm load aren't going to differ by more than 0.1
dB?

Hey, you're the engineer. You tell us. But if you can level-match, I'd
check it at 100 and 10k as well.

But in any case I will leave the amplifier's volume control in one
position and not touch it during each trial.

Documentation
---------------

I type everything that happens in time order into my laptop and
publish
it on the web.

Protocol
--------------

Basic ABX, but not with a switcher box-- instead I will ask my friend
to hook up one of the cables each time. This will take a while,
obviously, and I won't be able to do many auditions of each cable,
nor
will I be able to switch quickly.

Also, if I get tired or confused, I will simply not give an answer
for
the current trial, and start with that trial again later or another
day. Does that sound acceptable?

Uh, no. You should make your best judgment, and move on to the next
trial. I'd also set a limit in advance: Do eight trials today, or do as
many trials as you can fit in two hours, or something. (You migth want
to do a dry run to see how many trials you can reasonably do.) The
temptation to finagle when the numbers aren't going your way can be
strong, so you want fixed rules going in.

It seems to me that there's a small
chance this could be a way to defeat the test; i.e. refuse to answer
when I'm not sure, implying that I'm only sure when I've picked up
the
answer by non-sonic means. However, I will write down everything
that
happens including the times that I refuse to answer so people can
review it later.

Training
---------------

For the initial tests, I will ask my friend whether I guessed right
after each trial.

This really isn't necessary for training. All you need to do is listen
to each enough that you feel you can tell the two apart. If you wait
until you get a string of correct answers, you may never start!

When I'm confident that I've learned well the sound
of each cable, then the "test proper" will start. I will determine a
number of trials and write down my answer after each trial, but not
compare answers to the answer sheet until the proper number of trials
has been reached.


-Mike

On 7 Apr 2005 01:12:22 GMT, "Michael Mossey"
wrote:

Level matching
------------------

I don't have a good way to control levels.. I don't have a CD with a
test tone. Hmm, it occurs to me that I can burn one. I have a basic
voltmeter. Okay, I will do some basic measurements on a test tone. Is
a 1Khz test tone good? Also, it is a good assumption that two straight
wires into a 100K ohm load aren't going to differ by more than 0.1 dB?
But in any case I will leave the amplifier's volume control in one
position and not touch it during each trial.

It's almost certainly the case that you won't need to worry about
level-matching for this test, but if you are going to do it, then a
15kHz tests tone is better than 1kHz (any differences will most likely
be due to cable capacitance, which will show up at high frequencies).

Documentation
---------------

I type everything that happens in time order into my laptop and publish
it on the web.

Protocol
--------------

Basic ABX, but not with a switcher box-- instead I will ask my friend
to hook up one of the cables each time. This will take a while,
obviously, and I won't be able to do many auditions of each cable, nor
will I be able to switch quickly.

You will need to do at least ten trials, and preferably twenty, to get
statistical significance. The usual standard around here is fifteen
out of twenty for a 'success'.

Also, if I get tired or confused, I will simply not give an answer for
the current trial, and start with that trial again later or another
day. Does that sound acceptable? It seems to me that there's a small
chance this could be a way to defeat the test; i.e. refuse to answer
when I'm not sure, implying that I'm only sure when I've picked up the
answer by non-sonic means. However, I will write down everything that
happens including the times that I refuse to answer so people can
review it later.

Best to document everything, including 'don't knows'.

Training
---------------

For the initial tests, I will ask my friend whether I guessed right
after each trial. When I'm confident that I've learned well the sound
of each cable, then the "test proper" will start.

That's fine.

I will determine a
number of trials and write down my answer after each trial, but not
compare answers to the answer sheet until the proper number of trials
has been reached.

That is important, although you if you plan a twenty trial test, you
might want to check your results after ten trials, to see if there's
any point in continuing. Get more than four out of ten wrong, you
might as well save your time and grab a beer! :-)
--

Stewart Pinkerton | Music is Art - Audio is Engineering

"Michael Mossey" wrote in message
...
I found someone to help me. We are starting tonight. I'm going to do
some training of my ears first. I would appreciate any suggestions
that people can give me for improving the test.

Here's the system: I'm connecting a Marantz CD player to a CAL DAC to
an Antique Sound Lab MG Head OTL Mk III headphone amplifier to AKG K501
headphones.

The cables to test will run between the DAC and the headphone
amplifier. They a

Rat Shack 2M gold-plated, about $5
Transparent 2M, the one without network boxes, about $75

Making it blind
------------------

I will hang a sheet over most of the system. I still need to access
the CD player to start and stop things and put them in and out. The CD
player is at the bottom of my rack, so I will tuck the sheet into the
component above it, blocking everything else from my view. I will make
sure that there is no way I can see the cables themselves, but I will
have to sit in front of the rack.

My friend will hook up cables following my instructions, either A, B or
X as I instruct. He will determine X with a coin toss and write it
down. I will leave the room, he will hook up the cable and call me
back into the room. We will need to have some interaction as he will
call me, and we will pass each other coming in and out of the room. I
will keep my eyes closed so at least I won't pick up any verbal clues.
Hey it occurs to me that I can have him knock on something instead of
calling me so I can't pick up on any voice cues.

Level matching
------------------

I don't have a good way to control levels.. I don't have a CD with a
test tone. Hmm, it occurs to me that I can burn one. I have a basic
voltmeter. Okay, I will do some basic measurements on a test tone. Is
a 1Khz test tone good? Also, it is a good assumption that two straight
wires into a 100K ohm load aren't going to differ by more than 0.1 dB?
But in any case I will leave the amplifier's volume control in one
position and not touch it during each trial.

Documentation
---------------

I type everything that happens in time order into my laptop and publish
it on the web.

Protocol
--------------

Basic ABX, but not with a switcher box-- instead I will ask my friend
to hook up one of the cables each time. This will take a while,
obviously, and I won't be able to do many auditions of each cable, nor
will I be able to switch quickly.

Also, if I get tired or confused, I will simply not give an answer for
the current trial, and start with that trial again later or another
day. Does that sound acceptable? It seems to me that there's a small
chance this could be a way to defeat the test; i.e. refuse to answer
when I'm not sure, implying that I'm only sure when I've picked up the
answer by non-sonic means. However, I will write down everything that
happens including the times that I refuse to answer so people can
review it later.

Training
---------------

For the initial tests, I will ask my friend whether I guessed right
after each trial. When I'm confident that I've learned well the sound
of each cable, then the "test proper" will start. I will determine a
number of trials and write down my answer after each trial, but not
compare answers to the answer sheet until the proper number of trials
has been reached.

That sounds like a good test, Mike. I would only suggest that you make sure
your assistant disconnects the cables after every trial, and BEFORE he flips
the coin. There's a tendency to just leave the cables in place if there's
no change from the previous trial. This is bad news.

Also, I would be surprised if there was any significant level change between
cables. If there is, I'd investigate the setup thoroughly; there shouldn't
be.

Norm Strong

Follow up to this:

I did some blind listening to cables last night and did not feel
confident that I could tell the difference. I also observed some facts
about blind listening.

I agree with the objectivists that expectation during sighted listening
can affect what we hear. I observed that even in blind listening, I
formed "expectations." For example, on the basis of an initial
impression I might immediately make a conclusion about the sound as a
whole, and it was extremely difficult to separate the sound from those
expectations.

At the moment I'm probably not going to follow up with a more extended
blind test because I don't feel confident I can tell the difference
between cables. I may get some ideas about how to make the test
conditions more sensitive, and maybe I'll reconsider. I already use my
cheapest interconnect in my main system, anyway.

-Mike

wrote:
"Michael Mossey" wrote in message
...
I found someone to help me. We are starting tonight. I'm going to
do
some training of my ears first. I would appreciate any suggestions
that people can give me for improving the test.

Here's the system: I'm connecting a Marantz CD player to a CAL DAC
to
an Antique Sound Lab MG Head OTL Mk III headphone amplifier to AKG
K501
headphones.

The cables to test will run between the DAC and the headphone
amplifier. They a

Rat Shack 2M gold-plated, about $5
Transparent 2M, the one without network boxes, about $75

Making it blind
------------------

I will hang a sheet over most of the system. I still need to
access
the CD player to start and stop things and put them in and out.
The CD
player is at the bottom of my rack, so I will tuck the sheet into
the
component above it, blocking everything else from my view. I will
make
sure that there is no way I can see the cables themselves, but I
will
have to sit in front of the rack.

My friend will hook up cables following my instructions, either A,
B or
X as I instruct. He will determine X with a coin toss and write it
down. I will leave the room, he will hook up the cable and call me
back into the room. We will need to have some interaction as he
will
call me, and we will pass each other coming in and out of the room.
I
will keep my eyes closed so at least I won't pick up any verbal
clues.
Hey it occurs to me that I can have him knock on something instead
of
calling me so I can't pick up on any voice cues.

Level matching
------------------

I don't have a good way to control levels.. I don't have a CD with
a
test tone. Hmm, it occurs to me that I can burn one. I have a
basic
voltmeter. Okay, I will do some basic measurements on a test tone.
Is
a 1Khz test tone good? Also, it is a good assumption that two
straight
wires into a 100K ohm load aren't going to differ by more than 0.1
dB?
But in any case I will leave the amplifier's volume control in one
position and not touch it during each trial.

Documentation
---------------

I type everything that happens in time order into my laptop and
publish
it on the web.

Protocol
--------------

Basic ABX, but not with a switcher box-- instead I will ask my
friend
to hook up one of the cables each time. This will take a while,
obviously, and I won't be able to do many auditions of each cable,
nor
will I be able to switch quickly.

Also, if I get tired or confused, I will simply not give an answer
for
the current trial, and start with that trial again later or another
day. Does that sound acceptable? It seems to me that there's a
small
chance this could be a way to defeat the test; i.e. refuse to
answer
when I'm not sure, implying that I'm only sure when I've picked up
the
answer by non-sonic means. However, I will write down everything
that
happens including the times that I refuse to answer so people can
review it later.

Training
---------------

For the initial tests, I will ask my friend whether I guessed right
after each trial. When I'm confident that I've learned well the
sound
of each cable, then the "test proper" will start. I will determine
a
number of trials and write down my answer after each trial, but not
compare answers to the answer sheet until the proper number of
trials
has been reached.

That sounds like a good test, Mike. I would only suggest that you
make sure
your assistant disconnects the cables after every trial, and BEFORE
he flips
the coin. There's a tendency to just leave the cables in place if
there's
no change from the previous trial. This is bad news.

Also, I would be surprised if there was any significant level change
between
cables. If there is, I'd investigate the setup thoroughly; there
shouldn't
be.

Norm Strong

Yes, I had my assistant disconnect and reconnect the cables on every
trial.

My initial impressions of the sound did not correlate with the cables.
I.e., my friend hooked up cables a few times, and I just listened to
them blind and wrote down observations. Then he revealed the order, I
checked my observations against that, and there was no match. I did
not find any aspect of the sound that would let me tell the cables
apart. Except at the very beginning. I had strong opinions about the
first three trials and I was right about them. Easily a chance
phenomenon, but it is interesting to hypothesize that my ear was less
discrinimating after listening to many things--which is something I
observe, that the more stuff I listen to in an hour, the more it all
sounds the same. Of course that could also be because it is all the
same.

-Mike

Michael Mossey wrote:
Follow up to this:

I did some blind listening to cables last night and did not feel
confident that I could tell the difference.

Aww, does this mean you're not going to tell us how you scored? We were
really looking forward to that, you know.

I also observed some facts
about blind listening.

I agree with the objectivists that expectation during sighted
listening
can affect what we hear. I observed that even in blind listening, I
formed "expectations."

That's how pernicious it is. You don't have to know anything more than
that the two things you are listening to are different (not how, or
what they are), and they can sound different.

For example, on the basis of an initial
impression I might immediately make a conclusion about the sound as a
whole, and it was extremely difficult to separate the sound from
those
expectations.

A reason why longer listening might not help. Our brains can be so
stubborn.

At the moment I'm probably not going to follow up with a more
extended
blind test because I don't feel confident I can tell the difference
between cables. I may get some ideas about how to make the test
conditions more sensitive, and maybe I'll reconsider. I already use
my
cheapest interconnect in my main system, anyway.

Keep in mind that you did not use a particularly sensitive test
protocol. I know you don't want to believe that quick switching is the
best way to do these things, but it is. If there were an audible
difference between these interconnects, that would be the only way to
determine it.

bob

On 8 Apr 2005 22:33:25 GMT, "Michael Mossey"
wrote:

My initial impressions of the sound did not correlate with the cables.
I.e., my friend hooked up cables a few times, and I just listened to
them blind and wrote down observations. Then he revealed the order, I
checked my observations against that, and there was no match. I did
not find any aspect of the sound that would let me tell the cables
apart. Except at the very beginning. I had strong opinions about the
first three trials and I was right about them. Easily a chance
phenomenon, but it is interesting to hypothesize that my ear was less
discrinimating after listening to many things--which is something I
observe, that the more stuff I listen to in an hour, the more it all
sounds the same. Of course that could also be because it is all the
same.

Fine, so *test* your new hypothesis. Do say three trials a day for a
week, *then* check your score for the 21 trials.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Stewart Pinkerton wrote:
On 8 Apr 2005 22:33:25 GMT, "Michael Mossey"

wrote:

My initial impressions of the sound did not correlate with the
cables.
I.e., my friend hooked up cables a few times, and I just listened to
them blind and wrote down observations. Then he revealed the order,
I
checked my observations against that, and there was no match. I did
not find any aspect of the sound that would let me tell the cables
apart. Except at the very beginning. I had strong opinions about
the
first three trials and I was right about them. Easily a chance
phenomenon, but it is interesting to hypothesize that my ear was
less
discrinimating after listening to many things--which is something I
observe, that the more stuff I listen to in an hour, the more it all
sounds the same. Of course that could also be because it is all the
same.

Fine, so *test* your new hypothesis. Do say three trials a day for a
week, *then* check your score for the 21 trials.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Of course I want to test it. Why would you think otherwise? Actually
I have something I want to do first. My plan is to have my friend hook
up one of two cables at random. I will listen with different
selections of music, and in different ways. And I will write down my
impressions on a scale. For example, "harshness" vs. "smooth" on a
scale of 1 to 5. Sometimes I will do long listening. Sometimes I will
make an instant impression.

Then my friend will reveal the order to me. I will look for any
correlation in my data. Does there seem to be a pattern in long
listening tests, but not in quick impressions? Or vice-versa? Is
"harshness" a good place to listen, or is something else better?

Basically I'm looking for the best listening strategy. If there
appears to be no way to tell the cables apart after this experiment it
is pointless to continue.

However, if I find a pattern, then I will set up the 20 blind ABX
trials.

I only have one friend who is only occasionally free to help me with
this, so it's going to be a while.

-Mike

"Michael Mossey" wrote in message
...

Of course I want to test it. Why would you think otherwise? Actually
I have something I want to do first. My plan is to have my friend hook
up one of two cables at random. I will listen with different
selections of music, and in different ways. And I will write down my
impressions on a scale. For example, "harshness" vs. "smooth" on a
scale of 1 to 5. Sometimes I will do long listening. Sometimes I will
make an instant impression.

What you're proposing here is an "investigation." That's a good idea, but
why not start by replicating some of the experiments already run by others,
using a variable that's easily controlled. I would advise changing nothing
but the volume level. Can you tell the difference between 2 signals that
differ by 1db, and nothing else? Try it using music, sine waves of
different frequencies, white noise and pink noise. My guess is that you'll
have difficulty hearing a difference with music as a source; less difficulty
using a steady signal, either sine or noise.

Once you find the most sensitive signal, change the reference level. Try
60/61db, then 80/81db, then 100/101db. After you've found the signal that
makes a 1db level difference most obvious, reduce the difference from 1db to
0.5db, etc. etc. What I'm suggesting here is that you investigate your own
hearing ability before proceeding to something that is entirely terra
incognita. At least that's the way I'd approach the problem.

Cheers,

Norm Strong

Michael Mossey wrote:

I only have one friend



Isn't that always the case with us audio geeks?

wrote:
Keep in mind that you did not use a particularly sensitive test
protocol. I know you don't want to believe that quick switching is
the
best way to do these things, but it is. If there were an audible
difference between these interconnects, that would be the only way to
determine it.


I thought the most compelling defense against the Subjectivist Camp's
insistence that quick switching wasn't practical, realistic, or
ultimately revealing of sonic differences was that you DIDN'T have to
do quick switching!

Haven't DBT proponents (including the many on RAHE) repeatedly argued
that quick switching is NOT a requirement of these tests? That's what
makes "Audio Objectivism" so appealing to me: theoretically, Mr.
Audiophile can use his own equipment in his own room playing his own
material at his own pace on his own schedule...he can take hours, days,
weeks, months to reach his conclusion...the only difference between his
normal music listening activities & his participation in this
hypothetical double-blind ABX test are A) he can't ever know whether A
or B is in place at any given time, and B) at some point he does have
to make a guess as to whether X is A or B.

If that's not the case, where's the fun?

(And besides, regardless of whether or not quick switching is
demonstrably better for identifying audible differences, wouldn't slow
switching be just as good for identifying the inability to identify
audible differences?)

Buster Mudd wrote:
wrote:
Keep in mind that you did not use a particularly sensitive test
protocol. I know you don't want to believe that quick switching is
the
best way to do these things, but it is. If there were an audible
difference between these interconnects, that would be the only way
to
determine it.


I thought the most compelling defense against the Subjectivist Camp's
insistence that quick switching wasn't practical, realistic, or
ultimately revealing of sonic differences was that you DIDN'T have to
do quick switching!

You don't. But if you don't, there will be some audible differences
that you miss. OTOH, for interconnects it really won't make a
difference either way.

bob

Buster Mudd wrote:
wrote:
Keep in mind that you did not use a particularly sensitive test
protocol. I know you don't want to believe that quick switching is
the
best way to do these things, but it is. If there were an audible
difference between these interconnects, that would be the only way to
determine it.


I thought the most compelling defense against the Subjectivist Camp's
insistence that quick switching wasn't practical, realistic, or
ultimately revealing of sonic differences was that you DIDN'T have to
do quick switching!

Haven't DBT proponents (including the many on RAHE) repeatedly argued
that quick switching is NOT a requirement of these tests? That's what
makes "Audio Objectivism" so appealing to me: theoretically, Mr.
Audiophile can use his own equipment in his own room playing his own
material at his own pace on his own schedule...he can take hours, days,
weeks, months to reach his conclusion...the only difference between his
normal music listening activities & his participation in this
hypothetical double-blind ABX test are A) he can't ever know whether A
or B is in place at any given time, and B) at some point he does have
to make a guess as to whether X is A or B.

If that's not the case, where's the fun?

(And besides, regardless of whether or not quick switching is
demonstrably better for identifying audible differences, wouldn't slow
switching be just as good for identifying the inability to identify
audible differences?)

No, because extant psychoacoustic data suggest that 'slow switching'
(long intervals between sound samples) is a less sensitive means for detecting
subtle differences between the samples, than 'quick switching'. Ditto
long samples versus short samples. So an 'inability' identified in this
way might simply be due to the insensitivity of the protocol. That needs
to be addressed by trying the more sensitive protocol.

So, yes, Mr. Audiophile is free to do the test any way he wants, as long as
A and B are adhered to. But if Mr. A. *fails* to detect difference using his
own switching protocols (e.g., 'slow switching' using long samples),
Mr. Objectivist will suggest he try protocols considered to be more sensitive,
that involve short samples and quick switching. He might even suggest some
progressive ABX 'ear training' for differences. In doing so Mr. O is
trying to *help* Mr. A substantiate the differences he wants so badly to
hear, not hinder him. ;





--

-S
It's not my business to do intelligent work. -- D. Rumsfeld, testifying
before the House Armed Services Committee