Reversing absolute phase

not an excuse, just a reality. The much more common issue is polarity inverting circuits. An engineer mus be cogniscent of the polarity of every unit in his arsenal of gizmos and make sure to align them. I would hazard that most modern truly professional engineers do this.

"Since one polarity is often superior." No it's not. They're identical. The CD or LP can be recorded in either "normal" or "inverted" polarity* and played back in either. It helps if the playback matches the recording, but because most speakers are not polarity-coherent (with minimal or no crossovers) anyway, it only makes much of an audible difference on the ones that are. This subject is a hardy perennial, but that doesn't seem to make for much clarity about it.

* And many are recorded in mixed polarity. I have discs where I can bring the vocalist forward or put him/her in the background depending on where the polarity switch is set on my preamp.

Also don't confuse "reverse" on some pre-amps (was poular back in 50's/60's) as when it says "Stereo-Mono-Reverse) all you are doing is swapping what came out of left speaker for what now comes out of right".So if your bass is more prominent in left channel and drums more prominent in right it will be reversed that's all.Some confuse this with above info on phjase.I wish more digital players had this and compresson which is so easy to add and if your system is in absolute phase (after using polarty check ) all the way through an engineer went the other way it can make a huge difference.Compresson is something I'd like o see for making Car CD-R's or low level listening.Had an Adcom GCP 750 that had phase and it mae huge difference on some recordings.
Chazz

Dopogue, I have no idea why you would say that inverted and uninverted polarities are identical. On many recordings that just is not true. If by saying that "most speakers are not polarity-coherent" you mean that one driver is inverted, I would say that buyers should avoid them.

Mind you I am not saying that matching the polarity of the recording, if there is one, is a major contribution to the quality of sound, but it certainly adds to that quality.

Tbg,

this is a little confusing but I believe what Dopogue meant was that there is no qualitative difference between the two in and of themsleves, except relative to keeping the playback polarity the same as the original, which only shows up as significant on phase coherent speakers which refers not only to whether the drivers are alll connected in the same polarity but also to first order crossovers which maintain phase coherence throughout their range.