You're wrapping up production on a song and getting into the mix. Things are sounding pretty good, but when you demo your song on another set of speakers, the volumes all seem wrong. The vocals are too quiet, the snare is too loud, and you didn't realize how much a backing instrument was popping out of the mix. It doesn't just make your mix sound a little off. It makes your mix sound weak.
All of us want our mixes to translate. We want our mixes to be solid, and well-represented on every playback system they'll ever be played on. But that just doesn't seem to happen on its own. Why is that?
Understanding the Problem
The fundamental responsibility you have as a mixing engineer is balancing the levels of every track. It doesn't matter how cleanly the instruments may be EQed or how creative your effects are: if your mix doesn't have good volume levels for each instrument, it's not a good mix. And your ears will tell you this. You don't need me to.
The trouble is that it comes naturally to us to set the volume at a place that feels comfortable for us to work at: loud enough to hear detail, but not so loud that it's painful. This is a great place to work from during the production stage. But when mixing, we become numb to how things sound at that volume. And when we always listen on the same speakers, we forget that the frequency response and room positioning of your speakers not only affect how we EQ things, but how loud one instrument or element may sound against another. And further: the human ear just isn't good at discerning volume differences between elements when the volume is loud. Sure, we can hear it, but we can't nail it. And nailing it down perfectly is what we're after when we're making a great mix.
Sidestepping the Problem
Wouldn't it be nice if there was some easy technique that could eliminate this effect? Some quick workaround that doesn't boil down to 10 years of industry experience?
Lucky you, because there is.
This is going to sound so simple, and that's because it is simple. Your problem is that you are having a hard time discerning the balance of loudness across tracks when mixing at one, loud monitoring volume. The trick is to stop listening loud, and to start using a number of volumes instead of just one.
Finding That Magic
Just turn your volume down. Turn it down so low that you're having trouble hearing all the instruments in the mix. Because when the complexities of the mix start fighting for your attention at the edge of your hearing, suddenly the differences in volume become easier to discern.
Now that your volume is low, very low, start adjusting levels. You may find that your snare is getting lost and your hi-hat seems too loud. You're hearing the truth, so with the volume still really low, start making changes. Turn that hi-hat down, that snare up, and fix any other dominant elements that need adjusting.
Now it's time to pay attention to the fringes of the mix. Maybe that piano or synth sound isn't foundational to the track, but is just there to fill out the sound. Maybe the perfect volume for it is barely audible. Or maybe it deserves to be so quiet that you can't actually make it out as its own instrument. Sometimes this is what's best. If this is the case, you know you've found the right volume when you don't notice the instrument unmuted, but it feels like something is missing when it's muted. But if you do want to hear the instrument as its own unique sound, find the volume for it that allows it to be heard, but just barely. Let it support without dominating.
If your genre is modern and you utilize transition effects, like risers, reverse reverb swells, samples of drum fills, etc., this may be the moment you realize how off the volume may be. More than likely, your transition effects are punishingly loud, and you had no idea when you were listening with your volume turned up. But now that the volume is low, you can hear how dramatically the transition effects are burying the rest of your mix. It's time to fix that.
Is This a Mistake?
Now that you're mixing for low volume, are things going to sound good when you turn the volume back up?
In a word, yes. If the levels of your mix sound good with the volume low, they'll probably sound great with the volume high. It's just how things work out.
A Word of Warning
While you're making level changes at low volume, you may notice that some things could use tweaking with EQ. Maybe your vocal sounds a little thinner or thicker than you anticipated, and very likely your kick drum is lacking that low-end power you want it to have. You're tempted to start EQing things to fix the problems you're hearing. Don't. When you're mixing the levels of your tracks, your accuracy goes up when the volume gets turned down. But the opposite happens when you're EQing tracks: what you hear gets more skewed the lower you turn your monitoring volume. If you want to learn why this happens, do a little reading on the Fletcher-Munson Curves.
The rule of thumb? Make level changes with the volume low, and make EQ changes with the volume high.
Double-Checking and Triple-Checking
At this point, your mix is sounding good at low volume, and it probably sounds good at high volume too. But you're not quite there yet. You probably chose your low volume point arbitrarily, and it may also not be telling the whole story. It's probably a lot more accurate of a lens to inspect your levels than mixing at high volume, but it's still not perfect.
Now it's time to listen for a minute with your mix medium-loud. Now ultra-silent. Play with the volume in a few different places. A solid mix sounds good when it's the anthem of a deafening movie trailer in a theater, when it's at moderate volume playing in your car over the road noise and traffic, when it's getting buried by conversation while being played over a restaurant's speaker system, and even when it's just a tinny whisper in a grocery store. You want your mix to pass all these tests too.
So play around with the volume. Make sure the balance of lead vocal to percussion to primary instruments to backing instruments is maintained no matter where you turn the volume knob. You'll probably have to make a few changes beyond your first low-volume tweaks. And that's okay.
What Is My Process Like?
I normally produce fairly loud. Not deafening, but loud enough to hear everything going on with strength and clarity. When I'm about to export my mix to share with my mentoring group, I'll spend a minute or two listening at low volume and making changes to the mix. And when my mix is feeling close and I'm ready to do some reference checks, I'll spend at least five minutes fine-tuning level changes at one low-volume spot, then another five minutes or more listening at other low-volume spots, making sure the balance of the mix stays pretty consistent. After making changes, I always check that things still sound good at high volume. They usually do, but sometimes a compromise needs to be struck. And usually, testing at all those other volume levels helps me dial in exactly where that compromise needs to be.
The result? A strong, solid mix that sounds professional and exciting when played loud, but still keeps its foundation no matter how quiet it's played, over any amount of background noise. And that's the goal.