Jan 23, 2003 11:03 am there was an faq somewhere..let me find it for ya!
Mixing and 'phasing'
Posted on Jan 23, 2003 10:47 am
glynb
Member Since: Dec 16, 2002
I just read the guidance on mixing.
It starts with suggesting you mix the drums first and check for 'phasing' at each stage of the mixing process along the way.
Can anyone explain in layman's terms what 'phasing' is? I'm new to home recording and not sure what some of these terms mean.
BTW is there a glossary of terms on here somewhere?
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Jan 23, 2003 11:03 am there was an faq somewhere..let me find it for ya!
Jan 23, 2003 11:06 am check out the faq at the top of the page...it doesnt metion phasing though so i dunno - someone will though!
Jan 23, 2003 12:07 pm Here's a pretty good article about phasing. I found it pretty informative, although it's not very "laymen" in it's language.
pub157.ezboard.com/ffilmn...opicID=21.topic
Jan 23, 2003 09:21 pm Hey,
I haven't got the time right now to check that article - but I will have a quick bash at explaining Phasing very simply.
When you record any sound, it will create an impulse or waveform. This waveform is made up of peaks and troughs. Peaks are above the central line and troughs are below. You will have seen these waveforms if you have ever used a sample editor (like Cool Edit Pro, Soundforge, Wavelab, etc) or looked at an Osciliscope.
Phasing occurs when two or more signals are mixed together. Basically, if, for example, two peaks of equal intensity AND duration occur at the same time in two (or more) of the sounds being mixed together, they will cancel each other out (meaning you will hear nothing). This cancelling effect will occur to a lesser degree if two peaks of equal intensity BUT NOT duration occur.
So What does this mean?
Well, basically if you are recording a Snare drum and have 2 mic's on it - one on the top and one underneath then there is a good chance that there will be points in the two sound's waveforms where there are peaks (or troughs) of equal intensity because you are recording the sound of the same source (the snare drum). As a result, when the two signals are mixed together, the resulting sound may be very different - in most cases where two (or more) mixed signals are mixed out of phase the resulting sound will be very thin (due to the cancelling effect).
To combat this problem all you need to do is invert the phase of one (or more - if you are using more than 2 mic's on one soundsource) of the waveforms. This will basically turn all the peaks into troughs and vise-a-versa. As a result there will be no cancellation where there was cancellation before. However this may cause cancellation at other points in the waveforms.
Put basically, if something doesn't sound right (usually it will sound very thin & wirey) when you are mixing two (or more) signals (sounds) together, try inverting the phase of one of the signals (sounds) and see if that rectifies the problem. If it doesn't then try adding a different reverb treatment to one of the signals, or delay the signal slightly (literally move it slightly to the right on the timeline by about 3-4ms to push the waveform so the peaks and troughs will no longer cause phasing issues with the others)
Hmm - okay, so it got a little bit complicated, but hopefully that made sense - feel free to hit me back with any questions.
jues.
Jan 24, 2003 07:44 am Thanks for the explanation.
I'm not sure about 'inverting a phase' though, sounds a bit technical for me.
Can't say as I've been aware of this problem at all so far in my home recording career (4 months!) but I'll watch out for it when mixing.
Iwouldn't have thought it would be a big problem really, because snare, kick drum and toms are all operating in different tonal spaces. Though I could see this may be a problem with say a couple of guitars competing with a keyboard say.
But as i said, I'm new to all this and prepared to learn!
Jan 24, 2003 10:27 am jues is full of some great info the re, I actually had little idea of what phasing was, now I am more aware :)
Jan 24, 2003 09:07 pm glynb - glad that was of some assistance to you, but let me just set you straight on something.
In your reply you mentioned how you could see this might cause a potential problem with guitars via'ing for space with keys in a mix. - This is not to do with Phasing, that is a frequency clash.
A great example of how you might run into difficulty with phasing is when you record the same guitar track twice using identical techniques (eg: you don't move the mic, or change any settings after the first take). If you then mixed these two guitar tracks together you may throw the guitar sound out of phase which would drastically alter the sound - sometimes this is a good thing and it will open up a "hole" in the middle of the stereo field in your mix - but other times it can be undesirable.
Don't worry to much about phasing yet - as you progress with recording you will start to notice it in your recordings and / or experimentation. It's not something you need to fear, it's just something that is good to understand and know how to control.
jues.
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