If you don’t lay down plans before you get into the studio, you’re asking for trouble. If you don't, the sounds are going to end up clashing for attention and the song is going to sound like it was thrown together unless you figure out what you’re doing in advance and plan accordingly.
Which instruments will be up close, in your face, in the mix? Which ones will be far back? Which instruments will dominate the high frequency spectrum and which ones belong in the bottom? These are just a few opening thoughts, and by no means the whole shebang.
But don’t despair, because today we’re going to go through a planning process that could save you hours (or days, or weeks) in the studio trying to fix problems that could have easily been avoided.
A Three Dimensional Metaphor for Sound
Enter the sound cube. The sound cube is a tool that allows you to give each sound its own space and niche in the context of the track because the three dimensions are represented by their equivalents in the world of sound.
Frequency: the vertical axis is represented by frequency. The lower on the axis, the lower the frequency, and the higher on the axis, the higher the frequency. You don’t want to get too picky here, though. I’d advise dividing the frequencies up into low, low mids, high mids, and high frequencies. If you plan as though there’s a huge spatial difference between 100Hz and 200Hz you’ll end up packing things in too close together.
You can, of course, have more than one sound occupying one of those spectrums, but it’ll sound best if you space them with the help of the next two factors.
Stereo Image: stereo image is the left and right on the front of the cube. This is probably the most directly spatial of these factors, though the next comes close. You can place different instruments across the stereo field to maintain separation and intelligibility even if they occupy similar spaces in the reverberant image and frequency range.
Reverberation: reverberation represents distance. Are the sounds far away or up close? A vocal that’s totally dry is going to sound like someone’s spitting in your face, while one that’s very wet is going to sound like it comes from the other side of a cathedral. Because the reverberation to direct noise ratio increases with distance, our ear determines the amount of direct noise in what its hearing to place a sound.
So, with these three dimensions of sound, we can actually fit quite a bunch of instruments in by varying one or more factors. If I want to mix a bass guitar and an basson, which are both low, bassy instruments, I can push one further back or push them apart in my stereo field to prevent them from running together.
Of course, if you were after blurred edges between your instruments, you’d put the two bass frequency instruments in the same place on the cube.
This crude little diagram might help you visualize the concept.
Questions to Ask
I recommend sitting down and thinking about the track and what it needs to be comprised of. If you're recording someone else's work, this involves some discussion about how everything is going to fit together with the artist.
Always make sure you’re moving towards the end goal. Each sound in the piece needs to have its own niche, a place to exist that is not dominated by other sounds, unless the musician is deliberately attempting to blur the intelligibility and separate audibility of those two (or more) sounds. The end goal is to know where each and every sound is going to go.
So, what questions do you need to ask to determine this?
Which instruments am I recording? Know in advance. Studio experimentation is fun, but don’t bank on it saving the day during a creative dry spell. Let it happen but try your best to know what’s being recorded well in advance. Never depend on experimentation during the production phase. It’s cool in the writing phase of the song’s development.
What do I want each instrument to achieve? Each instrument needs to be in the track for a reason. Otherwise, it’s a waste of time, energy, money, and more importantly, a waste of some of the space in the song that could be used to emphasize or introduce other things.
Which instruments will occupy which frequency spectrums? Now that you know which instruments will be in the track, which of the four basic frequency spectrums do they fall into? Map them out on a cube diagram. If there are multiple instruments falling in the same spectrum, you’ll need to space them out via other means.
Which instruments will be close up, or pushed back? Determine which of these instruments need to be up close or pushed back. A good song will usually strike a pretty good spatial balance between frequency and reverberant space so that they don’t clash, but if they do…
Which instruments will be in which area of the stereo field? Where do you want each instrument placed? More direct instruments should be closer to center, while supporting instruments should pan off to the sides to make room for the lead instrumentation.
Don’t think about these questions in terms of how they make room for each other. Think about them in terms of how to best achieve what you need to achieve with each sound, with “fitting them in” smoothly as a secondary consideration. Things will tend to fall into place if you think that way.
Which instruments will be louder, quieter? Of course, one of the most basic of factors is which instruments should be louder or quieter, not in terms of space, but pure volume. Volume can cause points on the cube to swell into spheres, so to speak. Loud instruments take up more room than quiet ones. Remember to factor in relative loudness, too—if you want something to sound big and loud, you’ll need to include quiet instruments just to create that relative illusion.
Get it On Paper
Now, once you’ve thought it all through, you should get a clean piece of paper and mark it all up so you’ve got a handy reference guide. You’re going to forget this stuff if you don’t write it down, and if you confuse the brainstorming phase with this phase, you may get confused trying to figure out whether a note you've made was an idea or a decision.
There are a few ways you can mark this stuff up depending on your own individual preferences for dealing with information. Do you draw a cube and mark out various positions within the cube? Do you do a track-by-track listing with short descriptions? You might write:
Vocals: female, high frequency. Short reverb, up close in the mix. Dead center in the stereo field.
When it comes time to record and mix, you’ll know exactly where to put that track in the context of the rest. I do recommend playing with a cube diagram, at least in the final stages of your brainstorming session, because a visual reference lets you check that you’ve given each sound enough room and an appropriate spot.
If you usually find yourself battling unorganized, sludgy mixes, these ideas might help you to retain clarity throughout the recording process. Good luck!