Surround Sound Mixing | Panner Fundamentals 

To get the most out of a Dolby Atmos, or any Surround Sound Mix, it is important to understand the principles of Panning. Whether you're mixing in 5.1 for TV, Dolby Atmos for Film or Music, the placement of sound around the listener has a dramatic impact on how they percieve the material.

Pro Tools Surround Panner

If you’re new to surround panning in Pro Tools, it’s a good idea to take a moment to get to know the panning environment, so that you can make the most of your surround mixes. In this section, we’ll take a look at a basic 5.1 panner.

You can access the surround panning controls in any track’s output window. You can access this window the same way that you’ve done with stereo mixing, but the window that appears is significantly different.

Shown here is the output window of a mono audio track that is being routed to a 5.1 surround output.

Basic Panner Controls

Let’s start with the most basic elements of surround panning:

The box in the upper left of the output window represents an overhead view of the mixing space, with the front of your room at the top of this rectangular area. This area includes two important controls:

1. The dot within the panning field indicates the current pan location. This dot can be clicked and dragged to reposition the signal or to write pan automation. The dot (more properly called the Pan Cursor) will appear green when mix automation is being read or red when automation can be written.
2. You'll see a number of green speaker icons along the edge of the panning field. This number will vary in number and position depending upon the surround format chosen for the track's output.
   These icons serve not only as visual indicators of speaker locations (and output channels), but can be used to quickly reposition your signal-”clicking on any speaker icon will immediately move the Pan cursor to that channel.

When you’re mixing in most surround formats, there is a decimal point involved, with a number before the decimal and a number afterward -” "5.1", for example. The number after the decimal indicates the number of LFE (Low Frequency Effects) channels available to you. For example, the "1" in "5.1" tells you that there is a single LFE channel.

Though it is certainly an audio channel, the LFE isn't used for positioning. This channel is traditionally called upon for non-directional low frequency audio elements (like impacts and earthquakes), so it’s not included in the overall panning field. In the LFE section in the upper right-hand corner of the output window, you can choose the level of the track’s signal (if any) that will be sent to the LFE channel.

LFE Fader Signal Flow 

It’s important to bear in mind that the LFE fader is not independent of the track’s main fader, and is post-fader in the track’s signal path. That means that changing the main fader on a track will affect the output level of all channels of that track, including the LFE channel.

More Pan Controls

In many workflow scenarios, the basic pan controls in the top of a track’s Output window are all you need to get the job done. However, it’s good to know what is also available to you at the bottom of the window. In this section, you’ll find more ways to work within an immersive sonic environment:

1. The Panning Mode can be found at the bottom of your panning field. Clicking this button will cycle through different ways to pan:
   • X/Y Mode: This is the best choice if you want to be able to drag the Pan Location cursor freely.
   • 3-Knob Mode: This mode enables you to control the position of your sound using the Front, Rear, and F/R knobs in the Position section.
   • Divergence Editing Mode: This mode enables you to change the sonic width of the signal. This can also be controlled by the three knobs in the Divergence section.
   • AutoGlide Mode: This mode enables you to gradually move the Pan Location cursor from one position to another during playback.
2. Instead of dragging the Pan cursor around, you can instead use the knobs in the Position section of the window (3-Knob panning mode). Different surround formats will include different knobs -” here are the ones you’ll encounter with traditional surround formats like 5.1:
   • Front: This determines the position (left to right) relative to the front of the listening space.
   • Rear: This determines the position (left to right) relative to the rear of the listening space.
   • F/R: This determines the position relative to the front and the back of the listening space.

NOTE: Even when you’re dragging the Pan cursor, you’ll see the Position knobs move to reflect your changes, and you might notice something interesting: The Front and Rear buttons move together and have the same values. This isn’t a bug, but rather the normal function of those knobs when using the X-Y panning method. When you’re using 3-Knob panning modes, these two knobs are similarly linked by default, but can also be moved independently. To un-link these knobs, just click the linked-rings icon between the knobs.

3. If you’re new to surround mixing, you’re probably also new to the concept of a dedicated center speaker, so the Center % knob deserves some explanation: This knob determines how involved the center channel will be in positioning elements in the front of the listening space (which is where the screen is in post-production mixes). When the Center % is set to 100% (its default setting), any track that is panned dead center in the front of the listening space will only be heard through the center channel. On the other hand, if the Center % were set to zero, the Front Left and Front Right speakers would create a phantom center image.
   This control is most significant in audio post-production mixes, since dialog is traditionally panned to the center channel. Decreasing the Center % in non-dialog tracks can preserve dialog clarity in your mixes.

Pro Tools will give you visual cues as to the value that is set in the Center % parameter. As the value is decreased, the speaker icon in the output window will fade. When the Center % value is 0, the speaker icon will disappear altogether.

4. Divergence controls how discrete your panning will be. The default divergence setting of 100% will provide a traditional panning soundscape, with hard-panned signals being heard only through the speaker it’s panned to (for example, a track that was positioned at the bottom and far left of the panning field would only be heard through the rear left speaker). As divergence settings are decreased, increasing amouns of the signal will bleed into adjacent channels, narrowing the perceived width and depth of the sound field. If taken to extremes, if you set all your divergence settings to 0 all channels would output the same levels regardless of the position settings.

Viewing Pan Automation

Writing surround pan automation using any of the automation modes (write, touch, latch, and so on) is essentially the same as with a stereo mix -” the biggest difference is that instead of moving a single stereo pan knob to move a signal between two channels, you’ll drag the Pan Cursor to move your signal in a more immersive space.

Writing surround automation with the Pencil tool, on the other hand, is a significantly different proposition. This is because when you’re dealing with surround panning, there are multiple pan automation playlists involved. For example, if you were to bounce a track from left to right in a stereo field, you could easily create that by drawing with the pencil tool

This kind of workflow is easily done with stereo mixes, because you’re dealing with a single automation playlist (with the left channel at the top of the automation playlist and the right channel at the bottom). 

With any kind of surround panning (even a relatively basic format like 5.1), it’s a different story. Instead of having one automation playlist, you have a number of them. Here’s what you’d see with 5.1 panning:

• Front Pos: The lateral position in relation to the front of the listening space (with the left side at the top of the automation playlist and the right side at the bottom)
• Rear Pos: The lateral position in relation to the rear of the listening space (with the left side at the top of the automation playlist and the right side at the bottom)
• F/R Pos: The position relative to the front and rear of the listening space (with the front of the space at the top of the automation playlist and the rear of the space at the bottom)

All three of these automation playlists work together, with each one affecting a different aspect of the positioning. This can make for some pretty complicated-looking automation playlists. 

In the example shown here, the pencil tool has been used to create a single clockwise loop along the edges of the panning field. A keen eye can figure out the motion based on these playlists, but writing even simple surround pan automation with the pencil tool is far from intuitive!

Due to this complex interaction of multiple pan automation playlists, the most common way of writing surround automation in real-time, through the use of Pro Tools’ automation modes.

Surround panning often takes advantage or Pro Tools’ advanced automation features. These features can be learned in 210-level courses available at Promedia Training.

Author: Andy Hagerman

Avid Master Pro Tools Instructor

Andrew Hagerman has been a professional musician and teacher for the majority of his nearly 60 years. Beginning his musical life at the early age of eight as a tubist and bassist, Andy continued his studies at the prestigious Northwestern University in Chicago, Illinois. During his time there, MIDI and computer music were in their infancy, and Andy recognized the usefulness of these new technologies in aiding the creative process. He had the unique opportunity to learn these tools as they were being created and refined, and his quest for the best in audio and music technology ultimately led him to use and teach Avid’s Pro Tools