Interesting that we know that 'demagging does not add anything to an LP that would cause brightness', for example, but we don't know why it works and, again, speculate that the 'demagging' reduces stray magnetic fields on materials that can't possibly have magnetic fields, not withstanding the claims made by the suppliers of the demagnetizers, that rust has magnetic properties.
Has anybody attempted to measure the 'stray magnetic' field? Use an unshielded compass. If it isn't deflected, then the magnetic field, if it exists, is too small to make any impression on the magnetic cartridge. If it were and we can't detect it, then why doesn't the earth's magnetic field disturb the magnetic crtridge - it is stronger, after all.
Of course, then, perhaps the orientation of the cartridge relative to the earth's magnetic field should be audible.
I haven't heard any difference in sound when my turntable is oriented N-S or E-W.
Perhaps you have Dan_ed or Dougdeacon?
Call me skeptical.
Bob P.
