Localization vs. Depth – A Crucial Distinction in Mixing

A crucial realization in most producers’ development is that the sound stage concerns more than just left to right movement in the stereo spectrum. Beyond this two-dimensional range of movement, often referred to as “localization” or “pan,” there exists a front to back separation that is logically referred to as “depth.” Many new producers simply disregard the idea of depth in the mix; that’s not to say that they aren’t using depth, but they may not explicitly recognize it. Therefore, the goal of my post this week is to briefly clarify the three dimensional nature of the stereo mix that many of us work with on a daily basis.

Let’s start with localization, the concept that most producers are familiar with as “pan position.” Localization is the left to right spread of sounds across the stereo spectrum, referring to where the listener hears the sound coming from. Notice that I’m referring to the position of sounds here, not “width” which refers to how much space an individual sound takes up in the spectrum. In other words, there’s a big difference between where a sound is coming from vs. how wide that sound is. This may seem obvious upon reading it, but many people confuse these concepts and terms in conversation. We need to establish our definitions so that those conversations are actually useful!

Localization can be established through a variety of techniques, but the two most commonly used are panning and a clever use of short delays between the left and right channels of a sound (sometimes referred to as the “Haas Effect,” a technique I’ll cover in the future). I won’t go into these techniques in exhaustive depth here, but it’s helpful to know that panning isn’t the only way localization in the stereo spectrum is carried out. I’ll bet many of you are familliar with even more techniques – I encourage you to mention them in the comments section.

And now we move on to depth: Establishing the front to back position of a sound. In other words, depth is really an extension of localization but on a different axis. This confuses a lot of people at first because there’s no obvious parameter like “pan” to tweak in order to move something backward or forward in the mix. Instead, depth changes are generally achieved through the use of reverb and equalization.

Considering how we perceive the distance of an object in the real world, the two most important factors can be expressed in simple ratio relationships. The first ratio is how much low frequency information there is relative to the rest of the frequency spectrum. Generally speaking, a sound with fewer high frequencies and a strong low frequency response can have the effect of sounding far away. You’ve no doubt heard this in action when comparing how a fireworks show sounds far away vs. how it sounds when you’re right next to it.

The other ratio to take into account is how much reverb reflection there is relative to how much of the direct sound is heard at the listening position. If you hear more of the reflected reverb version of a sound than the direct (non-reflected) sound, you tend to perceive it as being far away. This makes perfect sense if you consider that the direct sound gets lower in volume the further you are away from the event. In addition to moving directly toward your ears, that sound bounced off of some surfaces and then reflected toward your ears. When sound reflects off of surfaces, diffusing and decaying around a room, we call it reverberation. Since there are potentially more surfaces to bounce off of between you and the event the further it is away, you perceive a more diffused version of the sound. That’s the ratio in effect: The direct sound gets lower and the reverb effect becomes more exaggerated.

To summarize, if you want to increase the perceived depth of a sound in your mix, experiment with these ratios: Lower the direct sound in relation to the reverberated version, and lower the higher frequencies in relation to the low frequencies. This discussion is greatly simplified for the sake of introducing these concepts. Indeed, many times you’ll follow these simple recommendations and realize that you’ve only succeeded in abstracting a sound’s place in the mix more than it was before. That may even be a good thing depending on what effect you’re going for.

This stuff is an art as much as it is a science, so practice makes perfect here. There’s no one-size-fits-all collection of settings or tools that are used, but I hope this article has provided some conceptual direction for your experiments!

Thanks for reading, and until next time please stop by nickstutorials.com for video tutorials on sound design and music production in Ableton Live.