Have you ever used two microphones on a guitar amp, snare drum or sound source and wondered why the sound was so thin and lifeless?
The answer is most likely that they aren’t in phase.
Something I learned relatively quickly is to look out for this and eliminate the problem as early into the recording process as possible. Therefore, my number one rule for multi-microphone recording is ALWAYS check phase.
But why is phase so important?
When multiple microphones are picking up from a sound source at different times we get what is known as phase cancellation.
An easy to understand example is on a snare drum with a top and bottom microphone. These microphones will most likely be different distances from the snare drum and the sound will therefore reach each microphone at different times, this may cause frequencies to cancel each other out.
Phase cancellation can be easily combatted; the answer is good mic placement, well trained ears and sometimes a flick of a switch!
The best method I have found is to solo all the microphones used on the sound source (so the two on the snare in the previous example) and check differenct phase combinations, whilst listening out for the combination which has the ‘fullest’ and ‘thickest’ sound.
This might not be the golden rule to phase but it has helped my recordings significantly and my mixes typically read positively when I use my phase metering tools.
These tools are great as they show you how ‘in phase’ your track is. However, as with all visual aids, I don’t recommend relying on them as your ears are typically the best tool for spotting problems.
The more microphones being used, the more phase issues may arise. Just take your time with the setup and dedicate time for phase checking and you should be all good.
If you’re worried about the phase of your microphones after you have recorded you can always adjust phase in your DAW. The trim plugin in Pro Tools is a handy tool for this. Logic Pro’s phase button can be found in the Gain plugin and for other DAWs there will no doubt be similar plugins that do the same.
Hopefully this topic has been addressed in a straight forward manner and has given you further insight into what phase is and how to combat it; now all that’s left to do is for you to go make some killer recordings that’re in phase and stop cancelling frequencies out!