out-of-phase

  • Thread starter Thread starter pacifica
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It means many things and is "fixed" in many ways... can you be more specific?

Technically it means that two waveforms that should have a certain relationship to each other in time have gotten out of whack so that this relationship has become offset. For example, if they are the same signal, and their crests and troughs line up with each other (by "line up" I mean occur at the same instant), and then one gets moved a little so that it plays a little earlier or later than the other, the two waves are now out of phase with one another.

To fix it -- line 'em back up again...
 
Another example would be if you miced up a snare drum with one mic on the top and another on the bottom. The one on the bottom would be 180 degrees out of phase in which case you'd want to "flip the polarity of the bottom mic so the two would be in phase.
 
out of phase

ok, i guess i was a little vauge w/ the questions. i guest it's just frustrating to know what the problem is, and not be able to fix it. i have a lack of dynamics, pretty common from what i've learned. but no remedy found yet. HELP PLEASE!!!!!
 
I don't think lack of dynamics is an phase issue.

But to continue with good explainations about how to KNOW you have things out of phase, and how to fix it:

To illustrated what "out of phase" is, take for instance a bass track and track copy it. Now, pan one hard left and one hard right. It should still sound like the bass is exactly in the center.

Now, apply some track delay to either one, say around 5ms. Maybe a hair less, maybe a hair more.

One of two things or both should happen:

1 - You will lose a LOT of low end in the sound.

2 - The sound will seem to "wrap around" you head if you are in a perfect triangle with the two monitors.

Another thing MAY be the sound seems to weight itself to one side or another.

That is one way you can tell if two sources are out of phase with each other.

Another is to simply pan two things opposit of each other, then MONO the mix. If you lose low end, you have a Phase issue. If the low end seems to increase, or at least stay the same, then the phase is cool.

As far as you "lack of dynamics" deal, I would say that many seem to post things about how they have TOO MUCH dynamics and are trying to fix that.

A good song arrangement, good playing, and good sounds will usually cure a song that lacks dynamics.

Also, you may be overcompressing things too. If you compress most things either while tracking or mixing, you will lose dynamics. Overcompression is something you want to avoid the most in the tracking phase of production, because if you do it at mix time, you can at least undo the amount of compression with another mix. But once something is tracked with too much compression, you will have to record it again.

You COULD try using an expander (basically a noise gate with the trim setting not set so hard) to try to increase dynamics a bit, but usually, you need a bit of dynamics already for an expander to work well (I have never heard an expander really "work well" per se, but I have heard slight improvements with using them).

Hope this helps. Good luck.

Ed
 
A (not so) Simple Explanation

if you hook up stereo speakers with the positive and negative leads backwards on one speaker only, you get an out of phase signal. Now, if you put a sound at center, it won't sound pinpointed in the center (*phantom channel), it will sound like it's coming out of both speakers or just some other location, depending on what type of sonic phenomena you have going on in your listening enviroment, sometimes it can sound like surround sound.

the reason, one speaker is moving in while the other is moving out (at the wavelength level, that is) the upper peak of one wavelength is playing in one speaker, while the lower peak is playing in the other.


* The phantom channel is an acoustic phenomena that allows for stereo positioning, when both speakers are playing the exact same thing, in phase, at the same level, and you sitting in between them... it sounds like there is a speaker in the center (or anywhere in-between) not the speakers themselves.

In my example you would correct it by reversing the leads on one speaker only, either one, doesn't matter.

The technique of reversing leads is sometimes used for custom wiring in a guitar, either the individual coils of a humbucker, or two separate pickups (what it does to the sound, I don't know, I've never tried a guitar and been told it's wired out of phase with the switch in "that" position).

a phase shifter, in stereo, will sweep in and out of phase, in a flanger-like style, giving you a 3D flange-like sound.

hope that helps you understand phasing
TX
 
ok, now i hav a better understanding of what "out of phase" means. is it possible to "fix" an overall mix that is out of phase. maybe a processor in sound forge or something of the like? sounds lame uh, oh well i'm a desperate guy.
 
Nice to read some good discussion about this much overlooked topic. Cheers
 
you guys have been so cool w/ trying to help. i just wanted say thanks.
 
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