EnginEARing Part 8: The Five Dimensions of Our Audio Mix
By Glen Stephan on August 22 2014 11:00 AM | Permalink | Author Info
Up to now we’ve spent a lot of time learning to hear and recognize frequency (Parts 5, 6 and 7). Frequency is indeed one of the most important dimensions of our mixes, but it is only one dimension of a multi-dimensional space in which our mixes live. Just as you and I live in the four dimensions of height, width, depth and time, our stereo mixes live in their own five dimensions, and learning how to listen to how they fit and move in those five dimensions is a key skill in out critical and analytical listening skill set.
It’s important to note right off that the five dimensions of a mix are not the same physical dimensions that we think of and live in our everyday life. While there are some similarities - music mixes have “width” and “depth” similar (but not identical) to the dimensions of width and depth we experience in our daily world, for example - these five mix dimensions are not the actual physical realities of our familiar four dimensions of space and time. They are instead the virtual dimensions of the sonic space that our mixes inhabit. They are the stage upon which we produce our musical play or the virtual canvas upon which we paint our musical picture.
The first dimension is width. This is probably the dimension that most resembles the real, physical dimension of width, and refers to the left to right pan space of the stereo mix. For example: Is the guitar mid-left or far right? Are the drums panned to simulate the listening perspective of the audience listening to a drum kit, or the drummer’s perspective, or neither? And just how wide is that panning; are the rhythm guitars hard-panned all the way to each side, and is that drum kit four feet wide or as wide as the stage?
Similar to - but not quite the same as - the depth of real space, this can refer to the apparent depth or distance to a sound in the mix or to the apparent total front-to-back depth of the mix. Is the amplitude (volume) of the various instruments used to create depth or emphasis (e.g. are the vocals placed well in front of a back-up band or orchestra to spotlight the singer)? Are spatial cues such as echoes or reverb, or even some high-frequency roll-off used to map a sense of distance (e.g. maybe the kick or tympani is heavily reverbed and somewhat muted to provide the illusion of distant foreboding)?
Depth often also refers to the apparent “dynamic range” depth of quiet-to-loud passages or instruments in the mix. Is the difference in volume between the quietist instrument or sound in the mix and the loudest, or between the quiet intro and the crescendo of the arrangement a large volume difference? Or is the mix of instruments and song parts fairly flat and even throughout?
Both of these aspects of depth, spatial and dynamic, often are - but are not necessarily always - interrelated.
This dimension bears no relation to height as we know it in real life; it does not describe any physical positioning up and down. Rather this just refers to the frequency spectrum we have previously been talking about (parts 5, 6 and 7), from the “low” frequencies of bass to the “high” frequencies of treble. One is not any higher than the other in physical space, just in the frequencies of the sounds.
This one is easy. It simply means “how long in time”. This can be the length (in minutes and seconds or in bars and notes) of the song itself or the length of a particular passage, solo, phrase, or any other property of the music mix.
Perhaps the most abstract, but one of the most creatively important of the five dimensions of our mix, “drama” refers to the dynamic quality of the width, depth and height over time - i.e. how they may or may not change within their duration.
For example, does the overall volume envelope of the song change over the duration of the song (does it build slowly to a volume crescendo, or, are the choruses louder than the verses, or, is the bridge subdued, etc.?) Or does the L/R panning, the mix balance, the mix depth, or the instrument frequency assignment move or change at all over time? Does the guitar cross-fade to piano over the course of a bar or two, or, do the number of overall instruments used in the mix change over the duration of the song, or, does the amount of reverb on any part of the mix vary with the intrinsic volume of the part, etc.?
EXPLORING THE DIMENSIONS
A good exercise for learning to listen to the five dimensions of a mix is to sit down with a good cross-section of music genres (except skip full-orchestra classical or opera for now) on CD or WAV format. It’s best not to use MP3-compressed or Internet-streamed music for this exercise, as those formats heavily distort all five of the dimensions in ways unhelpful to critical and analytical listening. Also have a piece of paper and a pencil (or a computer or e-tablet if we’ve forgotten how to write by hand ;) ) Don’t use a pen; chances are we’ll want to do some erasing or correcting as we go through the exercise. On this paper, we’ll make seven columns. Label the first one “Instrument” label the next five, “Width”, “Depth”, “Height”, “Duration” and “Drama” for the five dimensions, and finally label the last column as "Notes".
Pick one song from one genre on one day, and listen on a quality set of loudspeakers. Headphones can be used to help “drill down” in listening detail to width and depth and even some frequency assignment, but headphones alone can be deceiving if you rely upon them totally without referencing back to a more natural stereo soundscape from loudspeakers.
Start out listening to this one song by trying to identify the individual instruments and vocal tracks, writing each track we can identify on it’s own line on the paper. Leave several lines blank between each track listing so we have plenty of space to fill in information later.
After we think we have ID’d all or most of the tracks in the mix, let’s go back and listen to the song again, this time focusing on the first instrument track we listed, say drums, for example, and focusing in turn on each of the five dimensions and how the drums seem to work in each of those dimensions, making notes in each column as to how each of the recordings uses or take advantage (or not) of each dimension to positively (or negatively) affect the sound of the mix.
Then repeat the process on the same song from the beginning for the next instrument track, say organ, for example. And so on, repeating the process for each instrument we hear, including vocals (the human voice is, after all, really just another instrument.)
As we go along, there’s a good chance we may discover tracks that we didn’t notice the first time around when we created our paper list. That’s OK. We’ll just add them and their notes at the bottom of the list as we proceed.
The next day, we’ll repeat the procedure, but for another song from a different artist (preferably from another musical genre.) We can repeat this exercise for at least a week -longer if necessary - just until we have started getting used to the practice of listening to musical mixes in this analytical fashion. After this we can probably put the pencil and paper away and just keep practicing listening like this and making mental notes of what we hear whenever we can.
Figure 2 shows an example of such a notesheet displayed in a computer spreadsheet. The notations in this example have been kept short for clarity of illustration. We can feel free to make our own notes as detailed as we wish; the more detail we have, the more we have used our critical listening skills to hear them. Remember, however, these notesheets are not meant so much to be actual blueprints for every single fine detail of the recording as they are simply tools to help us build our listening skills.
A NEW FRONTIER
Once we get used to listening to and analyzing mixes in terms of these five dimensions, not needing notesheets to guide us along, we’ll see a whole new, wide canvas or stage on which one can paint or produce mixes, opening a whole lot of “space” to our ears we may not have appreciated, allowing us to critically analyze what we hear, whether it be our own mixes or those of a song we hear on our radio or playlist.
Next in part 9, we’ll sharpen our view of this textured, multi-dimensional stage of sound by learning some specific qualities and details of the sound within these dimensions to hear and critically analyze.