Gain staging, balance and phase, the bones of every mix

If I could tape one line above every new engineer's desk, it'd be that first one. Get the bones right and the polishing is a breeze. Get them wrong and no stack of plugins on earth will bail you out.

Three things make up those bones. There's gain staging, which is how you handle level all the way down the signal chain, then fader balance, meaning how loud each element actually sits against the others, and then phase, which is whether your tracks are pulling together or fighting each other. All three need to be right before compression, effects or the EQ work in chapter three make any sense.

Gain staging and the headroom system

Gain staging means minding your signal level at every point in the chain, from the input gain on the channel, through any plugins, to the bus, on to the mix bus and out the master. I'd call it the most common technical slip in amateur mixes, and it does more damage down the line than just about any other mistake.

The rule's simple. Every track in your session should average somewhere between -18 and -12 dBFS RMS before a plugin ever touches it, which is the headroom range most pro plugins are built to work in. Slam a vintage-modeled compressor with a signal averaging -6 dBFS and you'll get harsh, ugly compression (I go into compressors properly in the compression chapter). Feed it -15 dBFS and it sounds the way the designer meant it to.

Where your mix bus should top out

Before mastering ever enters the picture, the final stereo output of your mix should peak no higher than -6 dBFS, and ideally -10 dBFS or lower. That headroom is the elbow room your mastering engineer needs. A mix bus banging into 0 dBFS is one they literally can't work with, there's nowhere left to add level and no room for their compression or EQ moves.

Never slap a limiter or maximizer on the mix bus before you send it off for mastering. Hand over headroom and leave the loudness to them. That's how the pro handoff works.

Fader balance and the 80 percent mix

You'll often hear that a pro mix is "80 percent fader balance." I'd put it higher, closer to 90. A well-balanced mix with zero plugin processing sounds more professional than one that's been processed to within an inch of its life with a lousy balance, and I've heard that proven on more reference recordings than I could count.

Decide what matters most before anything else

Before I touch a single fader on a new session, I ask what the most important element in this song is. Nearly always it's the lead vocal or the main melodic instrument. Everything else is there to hold up and frame that one thing. If you can't spell out that pecking order in one sentence, you're not ready to start mixing.

My 10-minute balance

I set the first balance on every mix the same way, start to finish.

1. Pull every fader down to negative infinity, and don't park them at unity.
2. Start with the rhythm foundation, which means kick drum, snare and bass.
3. Bring in the main melodic element, the lead vocal or lead instrument.
4. Fill in the supporting parts like rhythm guitars, keys and backing vocals.
5. Add the ambient stuff last, so overheads, room mics and reverb returns.

Get it done in ten minutes or less. Your ears are at their freshest at the top of a session, and that's when you're most objective. Once it's set, jot the fader positions down so you can find your way back if you wander off later.

Panning so everything has room

I treat a few panning principles as hard rules. Kick, snare, bass and lead vocal sit dead center. They carry the power of the mix, and keeping them in the middle keeps the mono image strong. Rhythm guitars, backing vocals and supporting percussion head out to the sides, and you pan them in matching pairs so the picture stays even. Put one guitar 60 percent left and its partner goes 60 percent right.

Phase and polarity, the clarity killers

Phase and polarity problems rob you of punch, thin out the bass and leave a hollow sound that no EQ or compressor can patch up. They tend to hide in stereo and jump right out the second you flip to mono. That's one of the best arguments going for the mono check I harp on in chapter one, on monitoring, it's how you catch phase trouble before it ships.

Where phase problems come from

You'll run into phase trouble any time one source gets picked up by more than one mic. These are the usual suspects.

• On a snare with top and bottom mics, the sound reaches the top mic milliseconds before the bottom one, so blending them without flipping polarity gets you partial cancellation.
• Kick in and kick out mics work the same way. Different distances mean the sound shows up at different times.
• Put two mics on a guitar cab at different distances from the cone and you'll always end up with phase relationships that need sorting out.
• The overheads hear the toms as well, just later than the close mics do, so you get phase issues right across the kit.

How I fix it

I treat it as a mechanical job, nothing fancy about it.

1. Switch to mono and solo the two related tracks.
2. Flip the polarity on one channel with the Ø (phi) switch on your channel strip.
3. Flip back and forth between the two states. Whichever sounds fuller and louder in mono is the right one, so go with that.
4. If polarity alone doesn't do it, grab a time-alignment tool (or just sample-nudge the audio) and slide one track over a millisecond at a time until the low-frequency peaks line up.

That's all there is to it. No amount of processing will make up for phase cancellation, so you've got to fix it at the source before anything else happens.