Balanced connections

I'm with Doug Self on absolute phase. He states that for most frequencies, there is no detectable difference, but with one exception. I don't want to misquote him, so this is my interpretation.

Any very-low-frequency single "thud" creates a pressure wave, which is first outgoing, its decay - which is almost as loud - starting at the almost as instantaneous pressure "suck back." The successive vibrations could be in either direction as our hearing cannot discern direction on repetitive back-forth air movements.

He says that the original "thud" would have been face-on to the microphone capsule and suggests the only instrument recorded that way is a kick drum. He then discusses possible phase reversals that might occur in the recording chain, especially as the sort of music featuring a kick drum is quite possibly rock and/or  "commercial" and might have been misphased in the wiring somewhere due to the number of recording stages.

For the sake of the occasional fleeting "thud", the loudspeakers would have to be capable of creating the pressure wave, and the volume would need to be set pretty high to make a reasonable facsimile of the pressure wave. Even then, the listening room acoustics might "mangle" the pressure wave.

However, he notes that the purists argue so much about this, and the "average" customer believes them that it is best to design for absolute phase, even if that is at the cost of adding complication.

So, unless we're equipped to listen for that ephemeral "thud," what else could make us sensitive to phase? It cannot be imagined because sensible reviewers can detect a difference when swapping phases - something I discussed at length with Scott Faller. I, too, was able sometimes to notice a difference.

What I found is something that makes sense, and that is the difference between inverting and non-inverting stages. Inverting stages do not suffer common-mode distortion! Therefore, I surmise that absolute single-sided phase might not sound as good as a mixture of inverting and non-inverting as found in balanced send and receive circuits.

At that point, I decided to do an experiment, which was to connect an antiphase output to an antiphase input - single-sided - and compare it with both a fully balanced connection and a phase to phase single-sided connection.

I also "recruited" a few customers to try an R3 interconnect between their Majestic and Proprius pair. They might remember?

To my ears, the antiphase to antiphase connection sounded best, and that can be substantiated objectively because both use inverting send and receive circuits. These exhibit no common-mode distortion. The worst was the phase to phase connection, and from an objective viewpoint, it could be substantiated because non-inverting stages suffer common-mode distortion. The balanced connection was a little better than phase to phase, but antiphase to antiphase was best.

This was further substantiated because although the receiving circuit - in the Proprius - is an all-inverting series input, the non-inverting input passes both, and the inverting input passes only once.

What has this to do with the absolute phase of the music? Nothing!