Hi, Pete,

You are not confused. The audio world has misused the word "phase" when 
we mean "polarity." I TRY to use the word "polarity" when I mean that,
as in "flip the polarity of the left channel."

(a) I don't always succeed and sometimes succumb to the widespread 
practice of "inverting phase." I apologize for this.

(b) Not everyone knows the difference and many people use "phase" to 
mean "polarity."

I fear we have to live with this confusion for a long time.



On 2015-05-06 11:51 AM, Pete Tinker wrote:
> Please forgive this uneducated question.  Much of the discussion on this
> topic has focused on the "phase" of different transfers.  I'm not a
> signal processing guy, but to me "phase" involves the frequency of the
> signal, so changing the phase is a temporal shift in the signal (a
> lateral shift along the time axis) by a fraction of some wavelength.  At
> times in this discussion, it seems that the intention of changing the
> phase is a reversal of the amplitude of the digital signal (mirroring it
> across the time axis), for which frequency is irrelevant.
> If I have a stereo signal from a hill 'n' dale source, it seems the
> preferred next step is to invert the phase of one channel and then
> combine (add) the two channels prior to any digital noise reduction.
> What is the meaning of "phase" in this context?
Richard L. Hess                   email: [log in to unmask]
Aurora, Ontario, Canada                             647 479 2800
Quality tape transfers -- even from hard-to-play tapes.