There seems to be a lot of confusion about this. There always is. Mr. Ghost is correct.
Phase and polarity are NOT the same thing. A phase shift is a shift in time. A change in polarity is a change from a positive to a negative, or vice versa.
A simple example would be a 20 Hz sine wave that starts at zero volts, goes to a positive peak then decreases until it crosses zero, going negative until it reaches a negative peak and then returns to zero. Like this little symbol ~ .This is one complete cycle of 360 degrees. This happens 20 times a second so each cycle takes .05 seconds.
If this exact same signal had it's polarity inverted, it would start off going negative instead of positive, but would start at the same time.
If this exact same signal was phase shifted 180 degrees, it would start off going the same direction, but it would do so 1/2 cycle (.025 seconds) later or earlier in time.
Thus the comment about "flip the signal 180 degrees back to positive polarity" is wrong. If you are dealing with a repetitive waveform like a pure 20 Hz sine wave, than a phase shift of 180 degrees will look just like a polarity inversion. Draw a picture and check it out. But music is not so simple.
The comment from Mr. Brie is also a little off base. The recording is not out of phase, it has had it's polarity reversed. When you engage the phase button (should be polarity button)) you do indeed invert the signal. What was going positive will now be going negative, and vice versa. This can also be done by reversing the speaker leads. The common example is that of a drum that produces a very short WHAP sound. Lets say the initiation of the original WHAP sound caused a compression of air. The initial movement of the speaker cone should be towards the listener, which will also compress the air. If the polarity is reversed anywhere along the path form micrphone to speaker, the initial movement of the cone will be away from the listener causing the opposite. Whether this is audible is another story.
Phase and polarity are NOT the same thing. A phase shift is a shift in time. A change in polarity is a change from a positive to a negative, or vice versa.
A simple example would be a 20 Hz sine wave that starts at zero volts, goes to a positive peak then decreases until it crosses zero, going negative until it reaches a negative peak and then returns to zero. Like this little symbol ~ .This is one complete cycle of 360 degrees. This happens 20 times a second so each cycle takes .05 seconds.
If this exact same signal had it's polarity inverted, it would start off going negative instead of positive, but would start at the same time.
If this exact same signal was phase shifted 180 degrees, it would start off going the same direction, but it would do so 1/2 cycle (.025 seconds) later or earlier in time.
Thus the comment about "flip the signal 180 degrees back to positive polarity" is wrong. If you are dealing with a repetitive waveform like a pure 20 Hz sine wave, than a phase shift of 180 degrees will look just like a polarity inversion. Draw a picture and check it out. But music is not so simple.
The comment from Mr. Brie is also a little off base. The recording is not out of phase, it has had it's polarity reversed. When you engage the phase button (should be polarity button)) you do indeed invert the signal. What was going positive will now be going negative, and vice versa. This can also be done by reversing the speaker leads. The common example is that of a drum that produces a very short WHAP sound. Lets say the initiation of the original WHAP sound caused a compression of air. The initial movement of the speaker cone should be towards the listener, which will also compress the air. If the polarity is reversed anywhere along the path form micrphone to speaker, the initial movement of the cone will be away from the listener causing the opposite. Whether this is audible is another story.