The time old argument that we folks can hear the difference of absolute phase. I doubt it. I believe many mike preamps and amplifiers invert phase. The chance your recording's absolute phase is right or wrong is likely not much better than 50%. Whether that initial drum head pound sounds the same if the first pressure to reach your ears (assuming the wavelength is long enough for the distance between your ears to be of no consequence) is a rarefaction or a compression? I wonder. I bet with a specialized signal, and a trained listener, you can find out. As for 99.9% of most music and listeners, NOPE. You won't hear it. Just my two cents. Then again, just because 99.9% of folks cannot detect it, does not mean it is inaudible per se. All you would need is just one guy (or girl) to be able to tell repeatedly, and then.... well, nothing would change I guess except but for the fact that we would know ! (At least about the one person in the world who could tell). See where I am going with this? I think any decent psycho-acoustic model of hearing would include an RMS to DC converter equivalent. We know the pressure is going plus and minus very quickly, yet the tone loudness is constant. The conclusion to draw is that the ear-brain mechanism integrates the pressure variation over a slice of time (about a 30th of a second) and so this all happens so quickly we don't perceive it. What we perceive is loudness, and real world signals are going plus and minus both.... How to tell for sure.. Hmm. Maybe if I fired a gun at someone from close range. I have this neighbor I don't really care for anyway.... He doesn't like my dog either. It's ok to wire them all wrong, as long as you are consistent. Just don't wire them differently from one another. Then you are screwed. - Mr Paul