Quote Originally Posted by Pluto View Post
I'm still not sure you have it... The statement "shifting the phase of a music signal by 180" really has to be qualified by asking "at what frequency" because anything other than an electrical inversion is likely to have a phase shifting effect that varies with frequency.
Thanks Pluto, but what you have in red was what I'd assumed at the outset but couldn't reconcile with the reverse polarity out of phase concept; I had it as the relationship between phase and wavelength rather than frequency (post 29) but the concept is the same.

{Moderator's comment: Phase is one of the most difficult concepts to grasp even for those working in sound.}