Beat me to it Rich. I type too damn slow.
I just copied a link, you splained it all out. Good things come to those who wait!
What about the phase errors that occur within a recording, like drum mics too close to each other, or overdubs, EQ filters, crossed mic wiring. Most engineers don't bother fixing any of that, some try to follow the basic rules of mic placement, but then run it through a flanger anyway. Some use phase tricks to make it sound spacious. So even the phase mistakes have merit in an artistic sense. Even reference recordings do some of their phase tricks with their stereo mics to make the hall sound spacious.
But a single stereo mic pair in acoustic space with acoustic instruments offers a perfect phase on the media. Then it's up to the audiophile to decide how much of that he wants to preserve. Lots of phase twisting perils in a home stereo system, like tube amps and reflex ports. But there are even more in normal record production, so it's mostly moot.
I use LR12 crossovers. I like the compromise between low phase error and good transient accuracy compared to steeper filters. LR12 requires adjacent drivers to be opposite polarity. standard procedure is to put the midrange in absolute phase and the tweet and bass reversed polarity. It still sounds better than LR24 steeper filters, but when the kick drum hits, it sucks instead of blows, that's pretty easy to hear the difference. So I usually reverse my speaker wires permanently to make the bass driver and tweeter in phase with mid reversed, but if mix engineer reverses the bass drum polarity, or if the mastering engineer cuts the master with reverse pol for some reason, then it's nice to press a button to fix the bass drum, or whatever other instrument might be annoying with reversed polarity. Even though everything gets reversed, making some instruments wrong polarity, it might sound better.
It's something that the acoustic psychologists say we can't hear so we shouldn't worry about it. if you have enough nervosa, you can definitely hear it!