The Sound Rainbow

by James Coffey, B.M.Ed., M.Ed.

Imagine a painting of a blue house against a blue sky with a blue swing set and a blue dog running through blue grass. Now imagine the blues being exactly the same shade of blue. This happens all to often in recordings. In our imaginary painting most of us would agree that it lacks definition. Too many objects occupy the same part of the color spectrum. And when too many instruments occupy the same audio frequency, then you will lack clarity.

Think of sound as if it were the colors of the rainbow with each frequency being represented by colors. Now think about our painting and how you’d change it. How would you make every object well defined and painted with purpose? That is what we strive for in a musical recording. Every instrument being defined in its own proper place in the frequency spectrum.

The challenge is that we are often dealing with instruments that contain a wide variety of frequencies. And on top of that, a vocal that’s competing for the same space as well. This will cause tracks to fight with each other for attention with some instruments being muted by others. The term is referred to as “masking” and can be the number one challenge in any mix.

In the previous installment I discussed briefly the importance of the arrangement. Every modern recording with more than one instrument is going to run into masking challenges. Some of this can be dealt with in the arrangement by choosing where and when instruments overlap and how they interact in range and style. But even then modern instruments, by their nature and design, will compete for attention. So what we need is a way to take those sounds, adjust them and move them to places where they all have room to breathe and perform their own specific tasks. The major tools to assist us in the mix are EQ, panning and effects such as echo, delay and reverb.

Think about our imaginary painting and how you would make each object more defined. Certainly you wouldn’t want them to occupy the same space on the canvas. So you’d move some objects left or right while others remain centered. In mixing we do this by panning tracks left, right or center. You can use delay to widen the stereo field of a track or the whole mix. You may want some objects to be off in the distance and others more clearly upfront. Using echo, delay and reverb can push instruments back and bring others forward. And finally you can alter the colors of each object to better define their purpose. Or better yet, alter the colors so that each object compliments the painting as a whole. This is what we accomplish with EQ. Cutting or boosting frequencies to find the unique space for each instrument or vocal in relation to the other tracks.

Unlike a painting we have the option of being able to subtract frequencies that exist in a track. This should always be your first task. Boosting frequencies is a very effect tool but anytime you add to a track, you may get side effects. These are usually very small but can be cumulative to the point of doing more harm than good. Your first goal should be to make room for each track by finding frequencies to move aside to make room for others. Then you can use boost to help define an instrument or vocal if needed.

A common misstep in mixing is enhancing each track and instrument individually by soloing a track and altering the sound until that one instrument sounds amazing. Problem is you may have just caused it to sound worse in the mix as a whole. As in life, it’s not necessarily how you shine as an individual but how you work together with others!

An acoustic guitar has a rich and full sound that covers a huge part of the frequency spectrum. But in a mix, that means it has many frequencies that may compete with the drums, bass, vocals and other tracks. You may need to sacrifice some of those rich frequencies either in the guitar or the other tracks or both. It may sound less than ideal when soloed but when put into the whole mix, will actually sound better than ever because it now has its own space to shine!

Demo Acoustic Guitar Raw

Demo Acoustic Guitar Panned

Demo Acoustic Guitar Panned EQ

Demo Acoustic Guitar Panned EQ Delay


  1. Cut before you boost.
  2.  Whether boosting or cutting a frequency, do so until you hear a marked difference then back off a bit. These changes are cumulative and even though you may not hear a huge difference on individual tracks, it accomplishes a great deal with the entire mix.
  3. Your objective is to mix a track to make its purpose clear in the song as a whole. Soloing a track is perfectly fine but always consider its relationship to the other tracks.