Impact of phase inversion by preamp

Then I would say that the speakers may not be well aligned. The point of the mentioned test was to determine the audibility of polarity. We used polarity correct recordings of acoustic instruments, 80's pop with all live players recorded with polarity correct mics, analogue reverb [plate and chamber] and 80's pop with drum machines, synths, digital reverb and effects. The polarity correct channel inversion was a side show to demonstrate that identical seldom exists.

This statement is false. In the recording studio there is no guarantee that a certain track is inverted polarity or not. Many mixboards have polarity inversion switches, but they are there for effect, not get assure correct polarity. Some channels go through effects like reverb or phase shifters and no telling what polarity the signal is when exiting that.

In short, with any multi-channel recording all bets are off when it comes to polarity. Its a mixed bag, plain and simple.

In short, with any multi-channel recording all bets are off when it comes to polarity. Its a mixed bag, plain and simple.

Nonsense.
I polarity tested and corrected all the microphones.
I verified all the lines and electronics.
I made the recordings.
Some recordings were M-S, X-Y, spaced pair and some multi-mic.
Synthesizers are easily polarity checked with a sawtooth wave.
The tracks were 100% polarity correct.

Added effects do not alter the polarity of a recording any more than an acoustic hall alters the polarity of the instruments on stage. The phase of  an effect may differ from the signal, but the polarity remains unless purposefully inverted.

I found polarity switch can have one of three outcomes:
1- little or no effect
2- quite noticeable, but a matter of taste which way you go, or even leave you lost and undecided which one is the better
3- clear superiority of one setting versus the other
The cause must be in the recordings, as has been written in previous posts

Nonsense.
I polarity tested and corrected all the microphones.
I verified all the lines and electronics.
I made the recordings.
Some recordings were M-S, X-Y, spaced pair and some multi-mic.
Synthesizers are easily polarity checked with a sawtooth wave.
The tracks were 100% polarity correct.

Keeping in mind the simple fact that we've had a polarity switch on our preamps longer than anyone else in the world:


OK- If you have that sort of control you can pull it off (although the comment about synths is right out- don't go there- synths do all sorts of things with phase, pitch bending and portemento! However:

Added effects do not alter the polarity of a recording any more than an acoustic hall alters the polarity of the instruments on stage. The phase of an effect may differ from the signal, but the polarity remains unless purposefully inverted.

Reverb, phase shifters (think about what a phase shifter does...), EQ and the like can and do invert phase simply out of the design of the circuit, the number of gain stages and so on. If these effects exist on some tracks and not others, absolute polarity is easily lost. Now if you pay attention to those effect devices and compensate for their polarity (excepting phase shifters!), then you can make it happen.


But you are one in a million when it comes to this sort of thing! IOW with effectively all multi-track recordings you can't here absolute phase.

I first became cognizant of polarity in the mid 60's with the Command Series of recordings on 35mm tape. I forget how or why.

For a long time, LPs were marked as to preferred polarity. They encompassed the full gamut of recorded music from Pop to Opera. Obviously some were marked '??'

IOW with effectively all multi-track recordings you can't hear absolute phase.

I'd agree on many and maybe almost all made from the computer era forward, but there are plenty of multitrack recordings from 1955 onward when the Ampex Sel-Sync 8-track was invented that while their polarity is inverted overall, it is consistent from track to track. 

Now if you pay attention to those effect devices and compensate for their polarity (excepting phase shifters!), then you can make it happen.

When not working in a studio I knew to be polarity correct, SOP when using EQ, Limiter, etc. is to patch the track to a 2nd input, insert the device in the track and bring up the 2nd input. If the level increased, good to go. If not invert. Many mixing desks of the era included a Phase Correlation meter. It's a simple matter to use a mic of known polarity to check all the other mics in use. Of course, misteaks did happen ~<;-)

But you are one in a million when it comes to this sort of thing!

Many recording engineers I knew were every bit as concerned and delivered masters with correct polarity. Master Refs where checked to ensure the cutting house was polarity correct.