This is a clear explanation and description of the issues involved. Thanks for finding it for us!
jan didden
No. All that would prove is that SOMETHING is causing an audible difference. It in no way refutes SY's measurements. By the same token, it doesn't support his measurements either.
Again, this is going around in circles.
I was going to do a test that involved a group of people in one room & the equipment in another room unsighted by the group. The only equipment in the room being speakers. The people would not be told what the test is for.
I was going to assign a volunteer in the other room to put an attenuator on the cable randomly at his choice without knowledge about what they are or do.
The music would be played in pairs & the group asked to describe what they hear & to score which is better. The same music would be played for each test. This can only be done for a certain amount of time as it will get very boring for the participants. How many is recommended here?
Another group would be tested exactly the same except there would be no attenuators used or attenuators would always be used.
Are there any comments on this?
I was going to do a test that involved a group of people in one room & the equipment in another room unsighted by the group. The only equipment in the room being speakers. The people would not be told what the test is for.
I was going to assign a volunteer in the other room to put an attenuator on the cable randomly at his choice without knowledge about what they are or do.
The music would be played in pairs & the group asked to describe what they hear & to score which is better. The same music would be played for each test. This can only be done for a certain amount of time as it will get very boring for the participants. How many is recommended here?
Another group would be tested exactly the same except there would be no attenuators used or attenuators would always be used.
Are there any comments on this?
@ John ... and in the spirit of mutual learning and love!
first comment - no baseline. See the link I posted for a simple example.
second comment - an assistant choosing at random is not random. Its choosing. Random is random - if a person is involved in the choice it ain't random.
third comment - Describe which is better is a value loaded statement and will degrade the test. Identify if there is a difference has no value loading and is the ONLY thing that should be tested at the moment.
forth comment - The group will influence itself - the test has to separate the participants so they have no clues as to what they should be saying.
I could go on...
first comment - no baseline. See the link I posted for a simple example.
second comment - an assistant choosing at random is not random. Its choosing. Random is random - if a person is involved in the choice it ain't random.
third comment - Describe which is better is a value loaded statement and will degrade the test. Identify if there is a difference has no value loading and is the ONLY thing that should be tested at the moment.
forth comment - The group will influence itself - the test has to separate the participants so they have no clues as to what they should be saying.
I could go on...
Jan,
Please consider this as an open letter but addressed to you -others are free to comment openly or communicate privately amongst yourselves and agree what if any action you wish to take on the following offer: -
The guy who made the cables has previously expressed that the test cables are mine to do with what I like, so taking him at his word I would be willing to post both test cables to a third party of your choosing (please select one of your number that is universally accepted as being open minded, trustworthy and as straight as a die (we are not talking sexual orientation here
) for that person to assure himself that the cables are otherwise identical apart from the attenuation, then to re-identify the cables without any reference to me or anyone else and to keep that identity to himself alone. He may then test them himself, just for information, if he so wishes and then pass them on to one or more people to test for themselves. Immediately after the completion of each test the tester PMs the test collator with his findings to minimise (but not eliminate) the possibility of collusion. At the conclusion of the tests the final participant returns the cable direct to the chosen guy who re-identified them for him to confirm whether or not they'd been 'interfered' with and to collate and post the results.
Before I make this offer the plan must be agreed in advance and then adhered to for the SOLE reason that I do not want ad hoc participants involved as the tests roll out as I would risk losing contact with what are a very valuable and excellent pair of co-ax cables. I will stand the cost of the outward postage and would expect all participants to stand the cost of onward postage to the next participant with the return postage to me being stood by the result collator. It would also be better in terms of me keeping contact with my cables if each participant logged the onward postage to the next participant with the test controller/result collator and to post them securely with recorded delivery so that there is never any doubt as to who is responsible for the cables at any given time. Obviously I would ask that all participants respect the cables at least as much as they respect any of their own kit.
I have no pro-European bias guys, honest, but for logistics, time, postage costs and import duty reasons it would be best if this was limited to European based members only. And, at the risk of stating the obvious, it is obviously essential for the test to be meaningful that each participant has both a HiFace and DAC that can be connected by co-ax cable, and that each participants HiFace and DAC types are pre-registered with the test controller.
There, I hope I've covered everything but feel free to let me know if the meaningfulness (?) of the proposed test could be improved. It would also be nice (but probably unlikely ) if it could be generally agreed in advance that the results of any agreed such trial would be accepted as provig the point, one way or the other - I am that confident of the results - you are cordially invited to prove me wrong.
Over to you guys,
Dave.
Please consider this as an open letter but addressed to you -others are free to comment openly or communicate privately amongst yourselves and agree what if any action you wish to take on the following offer: -
The guy who made the cables has previously expressed that the test cables are mine to do with what I like, so taking him at his word I would be willing to post both test cables to a third party of your choosing (please select one of your number that is universally accepted as being open minded, trustworthy and as straight as a die (we are not talking sexual orientation here
) for that person to assure himself that the cables are otherwise identical apart from the attenuation, then to re-identify the cables without any reference to me or anyone else and to keep that identity to himself alone. He may then test them himself, just for information, if he so wishes and then pass them on to one or more people to test for themselves. Immediately after the completion of each test the tester PMs the test collator with his findings to minimise (but not eliminate) the possibility of collusion. At the conclusion of the tests the final participant returns the cable direct to the chosen guy who re-identified them for him to confirm whether or not they'd been 'interfered' with and to collate and post the results.Before I make this offer the plan must be agreed in advance and then adhered to for the SOLE reason that I do not want ad hoc participants involved as the tests roll out as I would risk losing contact with what are a very valuable and excellent pair of co-ax cables. I will stand the cost of the outward postage and would expect all participants to stand the cost of onward postage to the next participant with the return postage to me being stood by the result collator. It would also be better in terms of me keeping contact with my cables if each participant logged the onward postage to the next participant with the test controller/result collator and to post them securely with recorded delivery so that there is never any doubt as to who is responsible for the cables at any given time. Obviously I would ask that all participants respect the cables at least as much as they respect any of their own kit.
I have no pro-European bias guys, honest, but for logistics, time, postage costs and import duty reasons it would be best if this was limited to European based members only. And, at the risk of stating the obvious, it is obviously essential for the test to be meaningful that each participant has both a HiFace and DAC that can be connected by co-ax cable, and that each participants HiFace and DAC types are pre-registered with the test controller.
There, I hope I've covered everything but feel free to let me know if the meaningfulness (?) of the proposed test could be improved. It would also be nice (but probably unlikely
) if it could be generally agreed in advance that the results of any agreed such trial would be accepted as provig the point, one way or the other - I am that confident of the results - you are cordially invited to prove me wrong.Over to you guys,
Dave.
Were SY's measurements premised on the notion that if it is audibly different it will show up on his test?
Well I asked for an agreed test so take the floor, how would you do it?
I would go to my local university's psychology or audiology or physiology school and ask them to design an appropriate test methodology. I'd probably get them to carry it out to - that way I am in no position to influence anything.
Of course, the first question they will ask me is "what are you testing for ie what is the purpose of the test and what are you looking to identify (or not)?"
Wrong aardvarkash10, John is correct, you read the post again and my subsequent posts - no contact means no contact and no coaching means no coaching - would it make any difference if the 'cable guy' posted his side of this?
There are none so deaf ...... as Granny used to say.
Yes I was expecting and listening for a difference but, as I said previously, if the difference was subtle the '50/50 guess' argument would carry some weight, but the difference was not subtle, it was glaringly obvious. See my post above - I am quite happy for others to have the opportunity to listen for themselves. As we say in this part of the country, "Put your money where your mouth is."
Dave.
Ah come on this is a $12 device - forget it! Why not suggest to SY or others to go to your local Physics/acoustics lab & test for jitter - it ain't going to happen - you need to get real!
I also disagree with your statement supporting SY's accusation of coaching from the cable guy - just because there is the potential for this to happen in the test set-up doesn't mean that it happened!
Hi Dave - as you say in your post, you ran a short set of tests, called the cable guy and told him what you thought, he commented, and you continued testing.
I'm not mistaken am I?
The validity of the test is not in question Dave - it isn't valid. No argument about that I'm afraid.
Again, this is not a slur on your integrity or honesty. You honestly believe what you do and have no reason to mislead me on purpose. You are just subject to the problems of personal expectation and bias like the rest of us.
I'm not mistaken am I?
The validity of the test is not in question Dave - it isn't valid. No argument about that I'm afraid.
Again, this is not a slur on your integrity or honesty. You honestly believe what you do and have no reason to mislead me on purpose. You are just subject to the problems of personal expectation and bias like the rest of us.
No, but to say the the cable guy was coaching, as SY said, is a skewed interpretation of the possibility - do you not see this?
If you refer to the use of the word "coaching" and a possible implication that it was intentional then yes. Unfortunately in this type of testing the use of the word coaching to describe the possibility of a test participant intentionally or otherwise leading a subject is almost universal. Its not necessarily pejorative.
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