What Is Panning In Mixing And Music Production?

Panning is one of the most fundamental aspects of mixing in stereo and surround sound formats, and it's worth understanding in detail if we want the best results in our mixes and music production.

In this article, we'll discuss panning in more detail and uncover a few concepts and techniques to help you pan your tracks appropriately in your mixes. Note that I'll be focusing primarily on stereo mixing, as this is still the standard format today.

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How To Pan Tracks In A Mix

Panning is done via pan pots. The term “pan pot” comes from the days of analog, where potentiometers were controlled via knobs to alter the amount of signal being sent to either channel of the stereo output.

In today's digital audio workstations, we have virtual pan pots, but they work all the same. If you have a hardware controller (or any hardware mixer), you'll surely have the tactile knobs used for panning.

It's pretty simple, but I figured I'd start off with this point in this article.

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Understanding Mono, Stereo And Surround Sound Formats

To truly understand panning, let's unpack some fundamentals and discuss single versus multi-channel audio formats.

Mono audio, as the name would suggest (if you're familiar with the Greek etymology), has a single channel (mono = one). A mono mix, then, wouldn't have panning, as there would be no additional channels to pan to.

However, that does not mean that mono channels cannot be panned in stereo or surround sound formats. In fact, mono sound sources are panned all the time, and stereo sound sources can be thought of as two mono sources (one panned hard left and the other hard right).

So mono mixes (like mono sound sources and mono tracks) have a single channel.

Stereo mixes have two channels — a left channel and a right channel. This coincides with our basic auditory system (we have two ears) and offers directionality and width along the left-to-right panorama.

Panning a track in a stereo mix means adjusting its relative amplitude between the left and right channels. If the track is panned to the left, it will have more amplitude in the left channel than the right. Conversely, panning a track to the right will send more of its signal to the right channel versus the left.

Going to the extremes, again, panning a track all the way left would mean it's only in the left channel (zero amplitude in the right). Panning a track all the way right would mean it's only in the right channel (zero amplitude in the left).

Stereo tracks (within stereo or surround sound mixes) will have two channels to pan around. It's often the case that these two channels will be hard-panned left and right, though they can be panned elsewhere as well. For example, they can be brought in toward the centre to make them more narrow in the context of the mix.

So, to reiterate, stereo mixes (like stereo tracks) have two channels.

Beyond stereo, we get into the realm of surround sound, where there are more than two channels available to carry audio. The differences between the channels combined with how those channels are reproduced (speaker placement) will give a more immersive sense of sound beyond the simplistic left-right spectrum of stereo.

Panning sources within surround sound formats introduce new dimensions passed the left-to-right balance.

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What Is Stereo Width And What Role Does Panning Play?

Stereo width, perceptibly speaking, is the subjective width of a stereo mix. Technically speaking, it's made up of the phase correlation between the left and the right channels and the difference in the sound waves that reach our left and right ears (assuming we're in a proper listening position and environment).

Now, differences themselves don't truly give us width. For example, a “stereo mix” with no information in the left channel would have vast differences between the left and right, but it wouldn't sound wide — it would sound skewed to the left or mono. As another example, a stereo mix with waveforms that are completely out-of-phase would have maximum differences, though they wouldn't sound as wide as they would be disorienting.

A better way to define width is with phase correlation, which defines how well two signals are aligned (in this case, the left and right channels).

Let's take a phase correlation meter, which spans from -1 to +1. We'd have perfect alignment (the same exact waveform in the left and right) at +1 and perfect misalignment (the same waveforms but with opposite polarities) at -1.

For maximal perceived width without losing the solidity of the mix, we'd have a phase correlation meter reading of 0. However, in practice, it's better to have a stereo mix that's closer to +1 than -1.

Assuming we're in an optimal listening position, having a negative phase correlation will mean there are significant phase differences between the left and right channels. This will cause uncanny results, especially if the issue is present at lower frequencies, as the phase cancellation will sound unnatural to our ears.

So, in simpler words, width is about having differences between the left and right stereo channels, but not too many differences. Put differently, width requires contrast, having a strong centre image while also having information specific to each side.

Width is an important dimension of stereo mixes, and panning is our primary tool for achieving it.

We can pan different tracks to different directions within the stereo panorama to produce variances between the left and right channels. So long as we keep a decent amount of tracks panned to the centre, we should be able to get a nice, wide-sounding mix.

Generally speaking, when it comes to modern music production, the main elements (lead vocals and lead instruments) ought to be panned to the centre along with the bass, kick drum and snare drum. These important rhythmic and harmonic elements will provide a strong centre image. Then we can pan other instruments and effects around the stereo image to achieve a strong sense of width.

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What Is The Phantom Centre?

So, we understand that stereo mixes have left and right channels. When stereo mixes are played back, it's often via two speakers (and sometimes a subwoofer). This is true of headphones, earphones, studio monitors, stereo systems, and more.

While stereo mixes certainly have a centre image in theory (made up of the information panned to the centre that is, therefore, equally represented in the left and right channels), these mixes aren't technically reproduced with a centre speaker.

The phantom centre is the psychoacoustic effect that makes our auditory system respond to a stereo mix as if there is a centre image. Again, this is because the “centre” information in the stereo mix is equally represented in the left and right channels, and so if we're positioned optimally between the left and right speakers, these equal parts of the mix will hit our ears simultaneously. When they do so, our brains register the sound as coming from the centre, even though it's technically coming from equal sides of our heads.

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Panning Techniques

Now that we have a grasp over stereo mixing and panning, let's consider a few panning techniques.

There are effectively three strategies when it comes to panning:

1. Intermediate panning: tracks are panned across the stereo panorama, often incrementally, in an effort to fill up the stereo spectrum.
2. LCR (left, right, centre) panning: tracks are either panned hard left, centre or hard right in order to maximize the contrast and, therefore, maximize the width.
3. Hybrid panning: taking the concept of contrast via LCR but not being so strict on the panning positions.

I should mention that regardless of what methodology you choose to follow in a given mix, it's important to have balance across the stereo field. We don't want lopsided mixes with significantly more energy on one side of the spectrum.

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Pan Laws

Pan laws are DAW or mixer-specific designs that adjust the level of a signal as it is panned around the stereo panorama.

Pan laws are useful for maintaining the same relative perceived level of a track as it is being panned. All else being equal, an audio signal being played out of a single speaker (as if it were panned hard left or hard right) would be roughly 6 dB quieter than if it were played out of two speakers (as if it were panned to the centre). This is under ideal circumstances.

Most mixers and DAWs have a pan law between 3 and 6 dB to make up for the reduction in level as a track is being panned about the stereo spectrum. Some allow users to toggle the pan law on and off depending on their preferences.

Where pan laws are in effect, tracks will become progressively louder as they are panned away from the centre.

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Related Questions

What are faders in audio technology? A fader, in the analog realm, is either a potentiometer (most faders) or voltage-controlled amplifier (VCA faders) designed along a straight path/slider. Faders control audio levels, where sliding the fader upward increases the level. Digital audio systems use virtual faders to achieve the same results.

What is mixing? Mixing is the technical and creative art of balancing audio signals and combining them into a consolidated (often stereo) output. The goal of mixing is to properly balance a selection of audio tracks in a way so that the final mix has the maximum impact on the end listener, whether it's a song, a video/movie, or anything else that contains audio.