Preparing your mix for mastering: phase

In this series, we’re examining how to best prepare your mixes for the mastering process, by looking at some of the most common problems I see with DIY mixes coming into my mastering studio.

Today, we're talking about phase.

Phase issues can get tricky, because if you only trust your intuition, your ears can easily lead you astray. Having some basic understanding of technical fundamentals is important on this particular one.

There's always lots of room for experimentation when it comes to music production, but phase is an area where there's not a ton of wiggle room. It's a pretty hard spec, and if you get it wrong it can make mastering of your work (especially when it comes to vinyl production) impossible.

If your phase isn't done right, it can cause the needle to jump right out of the groove when your record is playing back. In digital music, phase issues in your mix can cause instruments to disappear when being played back on smaller bluetooth speakers, phones, or some types of computer speakers.

We all want a nice, wide stereo mix, but the technical process to achieve this can be a bit counter-intuitive sometimes.

Luckily, we have some handy (and free!) tools available that can easily help with this, provided you understand the engineering fundamentals.

The phase correlation meter

Please use a phase correlation meter!  This should be placed on your master track, and you should be referencing it regularly as you mix.  In Logic, it's available under "Metering".

Here’s what it should and shouldn’t look like as you’re using it.

A mix that has good correlation between the left and right channels!  This will sound wide, but also 3-dimensional, and play back consistently across systems.

A mix with phase issues.  This will sound squashed, thin, tinnier, and play back  inconsistently across different types of systems.

Solutions for phase issues

To fix this, you need to find the offending instruments or mics that are causing the phase issues, and adjust that track using one of these techniques: 

• a micro-second level delay (such as a sample delay).

• an autophase plugin.

• a micro spacing adjustment to a physical microphone.

• manually drag the waveform inside your DAW to bring it back into phase.

I also recommend checking your reverbs, and making sure they're EQ'd.  Low-end reverb mud flopping around your mix can easily cause phase issues.  Reverbs also tend to sound better with some of the low end rolled off.

You might also simply check your panning choices: I recommend trying to achieve a wide sounding mix by limiting your panning choices to 9-3 on the dial, to start.  If you can achieve this, your mix will sound wide, but also 3 dimensional at the same time.  That's what we want.

Phase is one of those more advanced concepts that's a little easier to demonstrate as opposed to writing about.

Inside Amazing Audio at Home, there's a full set of demonstration videos on this topic.