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Rick's article on phase

PostPosted: Sat Mar 13, 2010 5:52 pm
by thefridge
Greetings all, Ricks AT article on mic phase made sense, but I am wondering, even when say 2 mics of different make may be in phase, their envelope shape is slightly different, so to get a better sound, do I nudge one track so that the max. ampliude point line up, or what?
In the past I have simply a/b the track phase, and gone with the thicker, fuller sound, but maybe thats not as good as nudging?
Many thanks,
Mick F.

PostPosted: Sun Mar 14, 2010 10:14 pm
by rick
a lot of people nudge tracks to make them all line up in phase
its been going on as long as it has been possible to do it with computers .

i have done it because i could at times, but dont usually bother
some guys do it all day every day

the world isnt actually in phase at all times though , it pays to keep that in mind when your playing time machine games
with music

PostPosted: Mon Mar 15, 2010 10:43 am
by wez
the only time i do that sort of thing is if you are blending a bit of DI with the mic on a bass track, for example. obviously you'll want that in phase BUT even then, you want to make sure that it actually sounds better, not just looks better.

another gotcha is if you're working in something like PTLE, and you have plug in latency issues.... ie different plugs on the mic and DI channels. in which case, lining up visually doesn't work, you need to compensate for the delay.

if you've got two non-matched mics that are in phase, but look (ie sound) different.... well leave them alone i would think.

being in phase is good, except when being out of phase is better.

PostPosted: Mon Mar 15, 2010 11:34 am
by jkhuri44
wez wrote:the only time i do that sort of thing is if you are blending a bit of DI with the mic on a bass track, for example. obviously you'll want that in phase BUT even then, you want to make sure that it actually sounds better, not just looks better.

another gotcha is if you're working in something like PTLE, and you have plug in latency issues.... ie different plugs on the mic and DI channels. in which case, lining up visually doesn't work, you need to compensate for the delay.

if you've got two non-matched mics that are in phase, but look (ie sound) different.... well leave them alone i would think.

being in phase is good, except when being out of phase is better.


+200000

use your ears, use your eyes when it makes ur ears happy :-)

PostPosted: Mon Mar 15, 2010 11:54 am
by Chris H
jkhuri44 wrote:
wez wrote:the only time i do that sort of thing is if you are blending a bit of DI with the mic on a bass track, for example. obviously you'll want that in phase BUT even then, you want to make sure that it actually sounds better, not just looks better.

another gotcha is if you're working in something like PTLE, and you have plug in latency issues.... ie different plugs on the mic and DI channels. in which case, lining up visually doesn't work, you need to compensate for the delay.

if you've got two non-matched mics that are in phase, but look (ie sound) different.... well leave them alone i would think.

being in phase is good, except when being out of phase is better.


+200000

use your ears, use your eyes when it makes ur ears happy :-)


....and check the mix in mono from time to time.......

Re: Rick's article on phase

PostPosted: Mon Mar 15, 2010 1:20 pm
by Brent
This is my understanding..

Time alignment, phase and polarity are all different though related and semi-interdependent.

Think of phase as frequency specific (more correctly corner frequency in the real world) time domain distortion. A frequency/wavelength/time relationship.

Think of polarity with an acoustic pressure model. Positive and negative. 180' inversion changes whether or not a signal sucks or blows a speaker cone. Electrically whether the predominate half cycle is positive going or negative going. Lets not get into electron flow and poles at this point...

Time alignment is a crude way of manipulating the relationship of dominant corner frequency components and of paying for your lunch. With complex waveforms you win some and lose some.

Feel free to nitpick as I've resisted the urge to consult uncle Google and haven't had a coffee yet.

Brent Punshon

Re: Rick's article on phase

PostPosted: Mon Mar 15, 2010 2:19 pm
by Brent
And the point I was trying to make and completely forgot...

Sometimes a box like the Little labs IBP (or the various software knockoffs) will get you closer than nudging (in conjunction with nudging sometimes it's useful too). Depending on frequency (and therefore wavelength), nudging will "correct" phase relationships of some frequencies and degrade others. That's physics for you. Sometimes this works, sometimes it don't.

Tools like the IBP use an all-pass filter network to manipulate phase around a corner frequency (and the given bandwidth - though less and less as you move further from the corner frequency), so you can choose your poison a little more.

Wack a fuzz pedal on a bass guitar and it'll highlight these concepts.

Brent Punshon

PostPosted: Tue Mar 16, 2010 8:45 am
by thefridge
Many thanks everyone, I think that maybe nudging is a cover for actually mixing, given the limitations of my gear. I cant imagine many of the records that are my favourites were nudged- beatles, eddy current, sons and daughters etc, so back to using my ears not my eyes- cheers!
Mick F.