How to tell if lp is recorded with phase reversed?

You are talking about absolute polarity not phase. Phase,commonly, would be the relationshipo between two microphones or the relationship between two speakers like ones connected improperly. This is easy to hear.

Polarity on multi-mic'd recording may be all over the place. The kick drum trick with the woofer is fine and easier to tell than a lot of polarity issues but comb filtering in the high end in general or out of phase mics will not be corrected by flipping absolute polarity. You might like the sound one way better than the other though and your ears should be the judge. It's rare that i hear a one or two mic recording that is out of polarity.

Of course, the phase coherence on the gear you own makes a difference too. Hell, everything makes a little difference.

The easiest way I've found is to listen at moderate level with your hands cupped behind your ears. If the phase is reversed the sound is better with your hands there. If the phase is correct, the sound is worse. (Either way, adjust for the added apparent volume.) There are other aural clues, but that's the easiest way I've found. Try it.

As usual, excellent information from all, thanks for sharing. Tbg, I also don't know how PS Audio accomplishes the inversion. All I know is its performance for me has been very good. I know as in all other aspects of audio equipment, that there is always something better out there, the limits are only as deep as your pockets. For the money, though, the GCHP has made me a satisfied listener, besting any phono stage I've had, and besting my digital front end, in which I have nearly twice the investment. My system has reached an overall level of performance that, for now, has shown me that now is the time to turn to a previously overlooked side of system synergy, my room. That is where I will focus my energies and resources until the listening room is on a par with the capabilities of my system. Thanks again to all, so pleasureable to get and read helpful input from those willing to share their knowledge. Best regards, Dan

Islandmandan, I envy you the capability to invert easily, but I do not know how thee PS Audio does this. If it adds another stage, this sorely disadvantages the inverted sound.

As to how you can know, it is my experience that on many records you can hear little difference, but on some it is striking. Remember also that recording engineers may change the absolute phase between cuts further complicating the issue. Your ears are your only recourse as usual. I have lacked the capability to easy change phase for years and am certain that at least some of the records that thrill me are those that accidentally have correct phase for my system. I will also say that the quality of your vinyl front end including the phono stage can be far more important than absolute phase.

Buffyjames, you're talking about what happens when one speaker is connected out of phase. That's not the same thing as polarity switching.

Buffyjames,

that's if the two channels are out of phase from each other, ie. if one of your speaker's wires are reversed. No relation to what we've been talking about.

If the singer (soloist) comes from between the 2 speakers its in phase. If the soloist is difussed and no where in particular, its out of phase.

Just look at the woofer. When drum is played, woofer should move outward. If it moves inward, phase is reversed.

FYI, Silent Running Audio has an Absolute Phase chart that you can download which lists the recording labels that had a tendency towards recording in phase vs inverting. This is just a guideline but may be helpful.

... the difference is a sensation of "hollowness" , lack of dynamics and bass impact.

That is what we hear/feel in our system too. A small handful of our (classical) LP's give that giant sucking feeling. Big impacts start by pulling air away from you instead of hitting you with the initial wavefront. Creepy. We have no phase reversal switch, but swapping speaker leads is easy enough. Makes it all better, until you forget to swap them back!

I have tried fliping phase many times with different components (including the GCPH), and I always seem to prefer non- inverted.

I wonder if there is some sonic penalty to the switch flipping phase?
When I had the GCPH in the system I shoudl have played a disc that says it;s phaze in inverted, like SHelffield direct to disks I believe. This might make a good test if you have one of these LP's.

Now that I am running a bi amped system (with a GCC-100 as bass amp) I can remotely just invert the bass (below 60hz)
Sometimes I find it is fuller that way, but usually less distinct.
Sometimes bass is not there in a recording even with the bass at full, so inverted phase of just the bass gets it to pop out. - This is seldom though.

Thanks to all for sharing your knowledge with me. This seems a difficult parameter to pin down, which I thought might be the case. Trial and error (try it you might like it), scenario. Thanks again, Dan

Phase can't be screwed up, beyond reversal, during mastering. It is in the recording and mixing that different mic feeds can be reversed individually. Also, if more than one mic is used simultaneously on a given "take", they can conflict with each other, creating timing confusion and comb filtering of different frequencies between the mic pick up patterns. Subtler phase issues can arise within the pickup pattern of one mic due to impulse reponse anomalies although this is not usually discussed as a phase issue per se.

All this is to say that some recordings are phase coherent within themselves but are reversed from absolute phase, and some are confused within themselves which makes it difficult or impossible to determine and correct. In the case of the former, the difference is a sensation of "hollowness" , lack of dynamics and bass impact.

Of the recordings that are consistently in one polarity or the other (many are in mixed polarity, especially pop and rock records), it's roughly half and half "normal" and "inverted." There were lists of record labels in issues of the defunct "Fi" and "Ultimate Audio" magazines that consistently recorded in one polarity or the other; these are a good starting point if you really want to pursue the issue. Frankly, though, unless your speakers are polarity-coherent (all drivers wired with the same polarity) in the first place and have very simple crossovers, you're not likely to be able to detect polarity cues with any consistency. Sorry, but it's a real complex subject, and posts over on AA have not made it any more clear. Best advice is probably: Just trust your ears. Dave