Phase Problems

[Jtrain42]

Ok i have some really amatuer experience with homrerecording, and my friend has just purchased alot of equipment and we are looking to go professional sounding, as i'm sure everyone else is.

Our Gear:

Digi 02
57's 58's and a Ksm

One thing i have been reading about but really haven't got a good grasp of it is phase, i'm unsure as to what it is and how to eliminate, if somebody as simply as possible could explain it, and how to eliminate it, i would appreciate it. Thank you in advance.

 

[Stealthtech]

Much of the confusion about phase lies with the fact that there are several facets to this issue. Narrow arguments on the subject can be much like the story of the blind men and the elephant—one believes that the animal is snake-like, while another insists that it's more like a wall. Both sides may be right, as far as their knowledge allows, but both are equally wrong because they're hampered by a limited understanding of the subject.
Phase is a frequency dependent time delay. If all frequencies in a sound wave (music, for instance), are delayed by the same amount as they pass through a device, we call that device "phase linear." A digital delay has this characteristic—it simply delays the sound as a whole, without altering the relationships of frequencies to each other. The human ear is insensitive to this kind of phase change of delay, as long as the delay is constant and we don't have another signal to reference it to. The audio from a CD-player is always delayed due to processing, for instance, but it has no effect on our listening enjoyment.

 

[Jtrain42]

ok now that i know what it is how do i eliminate it?

 

[Stealthtech]

You should only really have phase problems when duplicate audio is in the mix. Either by there being two mics picking up the same source, or from an effect.

That being said... there are two ways to fix phase problems.

1. If the tracks are close to 180 degrees out of phase then use the switch on your track that changes the phase.
2. Hand move the track to match the phase in the lower frequencies. Since this is usually the main culprit with real phase problems this will often help.
3. Use a linear phase fixing gadget or plugin like:
http://www.voxengo.com/pha979/ -or-
http://www.littlelabs.com/ibp.html

The advantage to this way is it will adjust phase across the whole frequency spectrum (well I am not sure about the little labs thing).

 

[MadAudio]

Also, use the "3 to 1 mic rule." When using multiple cardiod mics on a sound source, like drums, you want to make sure that the distance between any mic is at least three times the distance between the mic and the sound source. This is supposed to eliminate any phase cancellation between the mics, but YMMV.

 

[bennychico11]

It's actually the "4 to 1" rule. at least that's how i've always heard it. but i guess just use your ears.

 

[manning1]

you can also get phase problems if pins on xlr mics are reversed or incorrectly wired. one reason i like magix music studio is it has a phase meter built in. so i can solo any track or groups and check the phase meter.
alternatively there is a free audio editor on the internet that has a lot of interesting features built in called sound engine soundengine.lunanet.gr.jp/english/ if i remember or google for it.
one feature it has is a phase meter. you might want to check it out sometime. its also a great audio editor for free with some interesting effects built in.
peace.