easy phase question.

D

DAS19

New member
Hey I was under the impression that whenever you start mixing you have to make sure the overhead hits line up with the toms, snare, and bass drum hits in order to reduce phase cancellation. Also in a case where a microphone is positioned further away then others like recording a guithr amp and having one mic close and one micing the room that after words they would need to be lined up to reduce phase. Now my roommate told me this idea was crazy.

Am I wrong is this totally ludicrous? My explanation for doing this would be the further mics get the sound later then the closer ones so they need to be lined up in order to make it sound right?

if anyone can answer this question it will be greatly appreciated.
 
It's not entirely wrong, but it's not quite correct either.

Many folks like to "line up" the drum hits and transients in order to sharpen and focus those hits, sure. Nothing wrong with that. The problem is, that does little to actually correct overall phase. This would bring everything into phase if you had two different tracks with identical waveforms in them. But this is not the case in reality.

The thing that everybody forgets is that every individual frequency has it's own individual wavelength. This means that if you capture the same sound with two different mics at two different distances, that for each microphone the various frequencies are going to be hitting the microphone at different phase angles (different points in their wave cycles). For microphone A, frequency X might be hitting it at 90° through it's cycle at this instant, but at that same instant at microphone B it might be at 120° because of the difference in distance. Another frequency (at another wavelength) will yield entirely different numbers at the exact same instants and locations.

Because of this, each mic is taking different pictures of different waveforms. Simple time sliding on the timeline will never be able to bring them into phase at all frequencies. In fact, there can be cases where you may get the attacks to line up, but lose the tone of the drum doing so because that shift just so happened to worsen the phase cancellation at a key tonic. (In such a case, the problem is the mic placement; go back and adjust the distance on one of them just enough to eliminate that tonic problem, and that should help.)

So, the best you can do is to line up the hits, or perhaps get a key frequency (and it's harmonics) in phase, but you can never get the whole waveform "in phase" at the same time.

G.
 
Or, you can just LISTEN and determine if it sounds good or if it sounds "out of phase". :)
 
I've tried that on some projects and always ended up moving everything back to their original times. It can be an interesting effect but it completely ruins any sense of space in the drum mix. You need those differences in time for the brain to really get a sense for the size of the room.
 
I get it now, moving an entire waveform will never bring everything back in phase. although some people like to line up hits its not really necessary.
 
If you solo say the snare mic and an overhead mic then use the phase switch, flip back and forth between phase and see which sounds fuller and that's usually the way to go same goes with the rest of the mics that are bleeding see which thin the sound and which cause a fuller sound, it's actually not hard at all and the difference is immediately noticeable.
 
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