Ask A Sound Guy

The 3 Dimensions of a Stereo Image.

 Mix Mondays is our weekly mixing help column, which aims to take the sting out of Monday with a little audio talk.

Engineers like to argue.  We like to debate about pieces of gear, signal chains, techniques and tricks.  We disagree about everything there has to do with production – as we should.  It’s a creative industry, and we can’t all be doing the same thing.  

There is one thing all old school engineers would agree on though – Meters Lie.  They really do.  They are great for things like diagnosing clipping, verifying signal flow, and monitoring processes.  But they don’t show tone.  They don’t show quality.  They don’t show you a real mix.  So How do you really “see” your mix?  You’ve got to see with your ears.

One way of thinking about mixing music to stereo (left and right) is to see the left and right speakers as creating a mix “wall.”  It sits in front of you in line with your speakers, and exists in 3 “dimensions.”

Red

Left to right, is represented to you with panning.  There’s a lot that goes into how we hear in stereo, and I won’t go into that here.  But panning lets you shift the “position” of a sound along the horizontal axis.  Panning devices do this by adjusting the volume of that signal in the two speakers.  Louder in the left makes the image “appear” to the left, and louder in the right makes the image “appear” in right.  Equal volume in the left and right speakers gives you a “centered” image.  

Purple

Up and Down is a dimension of mixing that relies on how we tend to interpret different frequencies of sound.  The treble of your EQ encompass the upper frequency range or the highs.  We tend to “hear” the treble frequencies as sitting physically above the lower end of music.  The bass or low end feels like it sits lower in the space of our mix.  I tend to think of what a physical drum set looks like when dealing with this aspect of imaging.  The cymbals sit up high, and the bass drum sits on the ground – lower than the rest of the set.  The toms tend to have an arrangement of higher to lower pitches.  

Blue

The Front to Back Dimension of mixing tends to be the most tricky.  You have to balance your use of volume and reverb to achieve your desired spacing.  On the simplest level, the more reverb you add to a signal in a mostly “dry” mix, the further back it seem to be.  But depending on how you mix, you can add reverb and delays to a signal and make it seem to sit in front of other elements in the mix.  I’ll give you an example: Say you’re mixing most of your elements into a signal large room reverb.  In order to make it stand out, might actually add a different plate reverb to give your vocal a strikingly different acoustic “space.”  There’s more math and science behind reverb interactions than I’d like to get into, but Reverbs and Delays tend to be a trial and error kind of processing.  Let your ears tell you if you’re getting the right effect. 

Other times simply keeping something louder than other elements of the mix makes it appear closer.  In a world where everything seems to be getting louder, this can be a real challenge.  So things like careful compression and volume automation come more and more into play.  Just try to keep in mind that you’re mixing for the sake of the song, not the meter.  It doesn’t always have to light up all the way for your mix to be “professional.”

Last Notes

Keeping some of these ideas in mind might help you setup your rough mix and open up space for items.  Just keep in mind that all the stuff you see in your programs is great – it’s just not the real picture.  The true image you’re creating has to be listened to thoughtfully. 

I’ve found that as a setup a mix for the first time, the best thing for me to do is deal with volumes and panning first.  Getting a rough idea of where things sit left to right and front to back.  Then I listen to the tone of tracks to get a sense of how their frequencies interact – especially noting where things “mask” each other, or overlap in ways that make one track hard to hear/comprehend.  Eq generally comes next with my main goal being to cut away those parts that are masking other tracks.  These two major steps help you do rough placement of items in your 3-D image and tend to make my job mixing a lot easier.  

Plus getting things roughly placed right away allows more time for the creative, lets-just-try-it moments, and we could all use more of those.  

Until next time, happy sound hunting.