Phase

[clong89]

How can one tell if a mic is out of phase? How do you reverse the phase if it is? And why is it important for them to be in phase?

CLong

 

[SouthSIDE Glen]

How can one tell if a mic is out of phase?

With what? For something to be "out of phase", there has to be something else with a different phase for it to be out of phase with.

One way to tell is to mix the two signals together. If the result winds up having a significantly lower amplitude/volume, you probably have phase cancellation issues.

Another is to use visual phase measurement display tools which most editors have built into them.

How do you reverse the phase if it is? And why is it important for them to be in phase?

It's importance is in the second paragraph above; phase issues tend to cause phase cancellations when out-of-phase signals are mixed together. These cancellations cause the resulting signals to sound messed up.

For a full exploration of this whole issue, head over to the website in my signature below, head to the Resources page by clicking on the "Resources" tab in the menu bar across the top, and from the Resources page, select the "Phase and Polarity" applet. This examines the issue in detail with a lot of plain language explanation and plenty of easy-to-understand pictures.

G.

 

[Armistice]

... what Glen said...

Phase is a relationship between two signals, so something can't be out of phase on its own.

You don't reverse phase either, you reverse, or invert, polarity.

Cheers