Quote Originally Posted by mtrycraft
But, that 20usec needs to be the difference between the two cables, in that example to cause the same shift. R.A.Grainer and the other referenced article could not come even close to those time periods, by several order of magnitudes.
Yes, I agree, the diff has to be between cables..that is why I gave the example of the bass lines on one channel only, somehow causing a nefarious shift of the vocals on one channel only..

I have experienced source shifting in headphones, one record in each ear, and varying the time relationship between the two...the image sounds like it is sweeping through the head. I can envision how confusing it would be if only a part of the musical content shifted that way.
Quote Originally Posted by mtrycraft
Varying it by how much?.
I don't know, but it varied from 100 milliseconds (obvious echo type) to zero. When I played a nightclub back in the late 70's, one of the effects I used was to play two identical songs at the same time, at equal levels. The phasing/flanging effect was neat, making a comb filter (inna gadda da vita style). But as the DJ, I had each turntable feeding one ear only, the perfect cancellation the dancers heard when shift=zero was when the image in my head was dead center. I could tell by the image location within my head, how the sound effect outside was going.

Course..this all assumes a skin shift is even real..

Quote Originally Posted by mtrycraft
Why would it be not real? All the present day texts claim it real and calculate it to be real. The audibility of the magnitude is the question.
No such data is available.
My apologies..when I say skin shift, I am not talking about the group delay stuff, 250 nano type..that is unquestionably beyond human hearing. I am talking about a complex musical content waveform being capable of time shifting some transient information by AT LEAST 20 microseconds (my arbitrary, simplistic threshold for image shifting). 250 nano is a waste of time w/r to audibility, IMHO. I must confess that I've not been able to peruse any of your links yet, I'm concentrating on putting boxes into and out of my minivan as the movers come Sat...but I'd be surprised to see that anyone has even examined their test setups for accuracy issues I point out. (I also assume some of the links include testing, and not just math.) But the present day texts I've seen still treat skin effect as a simple sine analysis, using the frequency domain without regard to energy balance equations..If I am correct, they will have to re-write the textbooks for the inclusion of slew rate based skinning. (not asking much, huh?) I still discuss my stuff with the guys here, and nobody has been able to shoot it down yet..(doesn't mean I'm right either).

In all my research, I've not seen anybody concentrating on the capability of the load resistor with it's slew errors...a very confounding issue for high speed high current low impedance measurement accuracy, and the very first item I hit upon in my skin test endeavors. I will (once I'm back up) be applying a rigorous testing regime to my load and current viewing resistors, to make sure the I/V phase errors remain very low up to at least 1 to 2 Mhz. That way, I can assure myself that the errors at audio freq's are negligable.


Tony: ""then wouldn't phase shift be a concern in stereo pair?""

Yes, it is..but, I'm concentrating only on left to right difference related to a skin phenomena...overall phase shift of each speaker is way, way over my simplistic approach, and something more suited to a speaker type forum..

Cheers, John