|
General Asylum General audio topics that don't fit into specific categories. |
|
|
|
General Asylum General audio topics that don't fit into specific categories. |
|
In Reply to: Re: Hmmm.. posted by morricab on October 11, 2005 at 07:47:12:
morricab: ""Fair enough John. You raise good and interesting points but I will have to verify some of what you say regarding the validity of the approximations used by Hawksford. ""
Reasonable approach, thanks.The book by Johnson I found contained an excellent chapter that covered this topic. (oops, I just realized, it was 2003 when it was published, I think I said 93 previously..) If you look in this book, he draws the toroidal eddy currents that occur within a wire, which results in the effective current density profile...I detailed this back in 2002, so I concur with the diagram..however, it is not clear if it was independently arrived at, or if he simply added my description..if not independent, our agreement cannot denote validation..
On the web, the scots guide site (Leseuf) on skin details this divergence of the exponential solution to reality, and somewhere states the 1/5th or 1/8th (I don't know which he used, authors vary) breakpoint below which the hf approximation is of no accuracy.
morriscab: ""Let me ask you another question: Assumming the invalidity of the approximations used, do you think the conclusions reached are therefore completely without merit? In other words, would you reach such a different conclusion if the arguments were more technically correct?""
All of the conclusions reached within that paper are not supported by factually accurate entities. If the arguments were technically correct, that scope photo would have been flatline at the gain levels and frequency he used.The results shown are errors which should have been avoided. It is inconsistent with scientific enquiry to swap conductors to produce results which meet expectations. (I must note that the substitution of a magnetic conductor (as told to me), was done to enhance the skin effect...unfortunately, the increase in internal inductance was not accounted for..this I believe was just a mistake, not done as subterfuge) It is inconsistent to provide test results from a scope face without amplitude or timebase information. It is inconsistent to provide inadequate information to allow others to duplicate the work.
As for skin effect having anything to do with speaker wires?? While his paper must be rejected in it's entirety as a result of all the errors within, that in itself does not discount the possibility that skin effect based audible effects do not exist. It just doesn't show it.
BTW, skin effect is really not a frequency based effect. It is a current slew rate one. It is only for convienience that the physics and engineering community model it with frequency as the independent variable. The real thing is a combination of current slew, material parameters, time, and geometry.
Audible? We are more sensitive to binaural stimulus than is currently considered. So far, I'm looking at .06 dB channel correlation sensitivity, and about 2 uSec time correlation sensitivity. At those levels, we will find that many things previously discounted are players. What comes to mind immediately are line cords, speaker wires, grounding schemes, large electrolytic supply capacitors, bi-wiring, IC's ground integrity, CD players, equalizers and tone controls, and those horible pan pots in the mixdown at the recording studio..ugh....
But affirmation of any of those first require a reproducible, accurate, and scientific approach to the issue of human localization sensitivity. Not incorrect magazine based tomes which lead down the wrong path. Those misdirect the uninformed, and generate arguments between the audiophile and the engineers..That is useless.
A pleasure..thanks.
Cheers, John
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Re: Hmmm.. - jneutron 10/11/0508:37:02 10/11/05 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
