Andre Visser said:
Well, diffmaker makes it about 1000 times more audible than just comparing it in listening tests.
There was a hilarious moment in the AES presentation when Bill alternated two tracks of a piece of music asking the audience what differences they heard. There were a few hesitating remarks like 'more highs' but nothing firm. Then he played the difference track, and there was a sousa band! Can you believe it, a complete sousa band mixed in at very low level, probably -80 or more dB down, and nobody heard it. It cracked me up.
Jan Didden
Re: Re: Re: Re: Re: Let me say it with a picture...
In a room not specifically treated, using a signal (white noise?) that will not reduce some of the room effects (as test procedure that uses an MLS signal will) you will easily see 1-2db of fluctuation without any changes.
Air temp, room air currents, furniture position, people position all make a difference.
This is why I urged you to run the test several times. I have done a lot of amateur in room speaker measurements and sure enough, there is a difference every time, even if the conditions are not notably different.
scott wurcer said:
In a room not specifically treated, using a signal (white noise?) that will not reduce some of the room effects (as test procedure that uses an MLS signal will) you will easily see 1-2db of fluctuation without any changes.
Air temp, room air currents, furniture position, people position all make a difference.
This is why I urged you to run the test several times. I have done a lot of amateur in room speaker measurements and sure enough, there is a difference every time, even if the conditions are not notably different.
scott wurcer said:Even under water
Andre Visser said:
Of course that 'sound stage difference' is caused by a difference in electrical signal at the speaker terminals. Diffmaker can extract that difference, but it cannot say that it is 'soundstage difference'. That would be up to the interpretation of the differences.
OTOH, if a listener says 'I hear soundstage differences' and Diffmaker shows no difference, we have a problem.
Jan Didden
alansawyer said:
I described it before in this thread, however I'll repeat it.
In my previous tests there was an error on my part, which will be corrected in all future tests.
The previous tests were done like this:
Testing an interconnect cable between CDP and preamp:
Two cables are connected in parallel (connecting cables in parallel is the mistake, which will be amended in all future tests) to the CDP's output, going to different inputs in the preamp.
A friend of mine puts on a selected CD, one I'm well familiar with.
Usually the same test is repeated with 3 different CDs – one is symphonic orchestra, the second is symphonic orchestra with chorus and soloists and the third is chamber music).
I sit in my usual listening position, with my eyes closed all along the session.
My friend doesn't utter a word – I'm the only one speaking.
Again, my eyes are closed all along the session and my friend doesn’t utter a sound.
I listen for few minutes, tell my friend what is my impression of the sound of that cable and ask my friend to change cable.
My friend writes down my comments, in line with each specific cable and changes cables.
I don't know which cable he started with.
Changing the cable is done 24 times with each CD – about 11 or 10 times for each cable.
At least once for each CD, the "change" is to the same cable, twice in a row.
When the session ends, I open my eyes and see which cable sounded to me in what way.
Then I may choose one cable over the other one.
Sometimes the difference in sound, if any, doesn't justify the extra cost.
Other times, there is a clear winner.
There is one preliminary selection – I don't test cables (or other equipment) which are beyond my budget.
The cables (and all other pieces of equipment) I test are always ones that were 'burned in', that is, worked for at least 30 days in cumulative calculation.
Joshua_G said:
Thanks for the explanation. Just please one point to clarify. Is this DOUBLE blind? I.e. the person doing the swap over should also not know which cable is which, only a reference such as A/B. This is especially true with your A-A swap system. The info collected then would need to be collated by 3rd party.
Also, the cables are going to different inputs on the pre-amp. Is that valid ?
Can you provide some statistical data on results? In particular I would like to know the effect of burning in (although I think you won't know that if they are all "burned in" before testing), and how frequently the A-A swap rendered a difference in sound.
syn08 said:
I can understand that it drives you nuts. It drives me nuts too.
To have you personally confabulate that I am of the same thinking- is quite insulting.
Nothing of what I wrote was even remotely of that nature.
This is seemingly the area where you fall down on this thread and board in general. It is one where your personal world view is the only truth.
After repeated attempts to reason with you, nothing has come of it.
Now is the time where I (metaphorically) put my hand on the side of your face and push you aside -where you belong- until you learn how to relate better.
For me to tell you of the workings of the marketplace and indicate nothing of any nature that says I attempt to cheat anyone of anything..to indicate that I don't like it either...and then tell me 'you are calling the cops' on me?
You sir, are pathetic. Your interpretation of my words is also indicative of psychosis.
~~~~~~~~~~~~~~~~~~~~~~
For the rest of you, this is a clearly articulated example of what happens when something threatens one's world view.
They attack.
Thus the reluctance of those who can contribute--to contribute. We just simply get bit. Repeatedly.
Why bother when this is what we get for our efforts?
Joshua_G said:
Don't think so
. "engineer choosing audio equipment for ones' own use", replace "engineer" with "technician", "doctor", "witch", "psychologist" etc... and you'll get the same results. Except that the other professional organizations may have something to say about the denomination 
Your rage and personal insults denotes I successfully touched a few sensitive buttons
Sometimes the "swapper" knows, mostly with CDPs and amplifiers, sometimes he doesn't, mostly with cables. Then he marks them as "the yellow pair" and "the brown pair", or similar description.
Different inputs were used in previous tests. It will be amended in all future tests.
Statistically, the results are 100%. That is, each and every time I give either the same, or unmistakably similar description to each cable.
I cannot tell the effect of burning in, I just do it as precaution.
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