Reversing Polarity -- Voodoo or Easy Tweak?

Jeff_jones...Speaking of what I will call "relative" phase (one speaker with respect to the other) the "proper" phase is not always clear. Out of phase signal has a diffuse and directionless quality, and that might be what the recording engineer intended. In a matrix multichannel setup out of phase signal localizes to the rear channels, so reversing one set of speaker wires just swaps front and back speakers. When played back on a two-channel system a source that is intended to be well defined center front (typically a soloist) is a monaural signal (same in both channels). All recordings have some degree of out-of-phase signal, often nothing but ambience. However, there are some exceptions. One good example is the recording by Buffy Sainte-Marie, "The Angel" where out-of-phase signal is used with stunning effect.

I do not suggest that anyone deliberately connect stereo speakers out of phase, but a signal being out of phase is not inherently "wrong", and can be used to great effect when a recording is mastered.

Whoops! I should have said that reversing phase of one channel BEFORE MULTICHANNEL DECODING will swap front and rear. Doing speaker wires in a 2-channel setup will localize ambience, and make the soloist diffuse and directionless.

Tvad and others

Didnt know it was called "absolute phase" - this is what was recommended on the first edition Dave Grusin vinyl.

So I guess the answer is like biwiring: it depends?!

The correct term when talking about wiring speakers is polarity as stated in the original question, not phase.

Phase has to do with time, polarity has to do with whether a signal is going positive or negative. If a speaker is wired with the wrong polarity it will be going out when it should be going in, and vice versa. I have friend who claims he can tell when it is reversed because a vocalist will sound like they are gulping air instead of exhaling.

When 2 signals are out of phase it means that one or the other has been shifted in time, it occurs earlier or later in time than originaly produced. One example is a crossover network. They not only attenuate the signals outside their passband, they also phase shift them so they occur at a different time relative to those in the passband.

The fact that many manufacturers use the terms interchangeably adds to the confusion, just as Eldartford did in his post. In the first part where he is talking about wiring the speakers the correct term is polarity. In the second when he talks about the Buffy Sainte-Marie recording the correct term is phase. This deliberate phase shifting is the same thing Hendrix did to get that swirling effect with some of his recordings.