When I first heard that clip gain was being added as a feature in Pro Tools 10, I thought it was a terrible idea. “We already have an excellent automation engine,” I said.  “Why over-complicate things by adding yet another layer to the onion?”  Then I actually started working with clip gain, and boy was I wrong!  What I thought was a wasteful addition turned out to be one of the best new mixing tools in years.

Clip gain is a carry-over from Avid Media Composer; it is the default method used by picture editors to raise or lower volume.  Essentially they apply an amount of gain up or down on a clip-by-clip basis.  Traditionally, when opening an AAF from Avid and importing into Pro Tools, we would convert this clip gain into automation because it was what we used for the same purpose.  But now we have the ability to use clip gain in addition to volume automation, and can therefore bring it directly across from Media Composer.

So initially this seems redundant.  Why add another layer of automation on top?  It’s just going to be confusing!  But it turns out that it’s incredibly useful.

The first aspect of clip gain that makes it amazingly useful for post production is that the waveform display actually grows or shrinks according to how much clip gain is applied.  This gives you an immediate approximate visual indicator of just how much the level has been increased or decreased when clip gain is adjusted.  This is especially handy when mixing reality TV, where dialog levels often swing wildly from clip to clip.  When dealing with a frankenbite where the relative levels of the clips are miles apart from one another, you can simply take one clip and adjust its clip gain until its waveform display is about the same as the adjacent clip.  This is dramatically better than doing wild ramps with the fader, and also reduces the need to “checkerboard” the dialog clips across several dialog tracks.

The feature that instantly sold me on clip gain, however, was the ability to adjust it via a key command.  Clip gain can be adjusted via the key command “shift-control & up- or down-arrow”.  The amount of gain applied per key-press is defined in the editing tab of the preferences, and can be set in 0.1dB increments.  I typically set it at 1 or 2 dB.

So what’s the implication of this?  With this workflow you can select one or more clips and trim them all up or down with a single keystroke (or just repeat the keystroke for additional gain adjustment).  You can do this while stopped or while in play.  This volume adjustment is totally independent of your volume automation, meaning that you can keep all your relative mix moves and just bring the overall level up or down.  “But we can already do this with trim automation,” you say.  True, but that requires going around for a second pass, flipping into trim, and carefully managing the coalescing of the trim automation.  The same adjustment can be applied via clip gain while still playing the first pass.  Also, trim automation runs out of upward gain at +12dB, whereas clip gain can go three times as high, all the way to +36dB.  Of course, there’s nothing to stop you from using both!

Because you can use this across multiple clips at once, you can bring an entire mix or any part of a mix up or down with a single keystroke.  Again this can be achieved with trim automation, but this workflow is potentially faster.

The other critical distinction between adjusting your mix via clip gain and adjusting it via trim automation is its position in the overall signal flow.  Here’s a quick overview of signal flow for an audio track in Pro Tools:

audio file on disk –> clip gain –> plugins –> sends –> volume fader –> master fader –> output

This is where clip gain can really start to make a difference for mixers.  Notice that clip gain affects the level of your audio before it enters the plugins inserted on the track.  Trim automation only applies to the volume fader, so this affects your signal after plugins and sends (except for pre-fader sends).  Consider, again, the case of the reality TV frankenbite dialog.  You’ve got a few dialog clips hacked together to make someone say the phrase that the producers want, and the clips are all from different times at wildly different levels.  If you use clip gain to adjust them all to relatively similar levels, then they will enter the dynamics section of your Channel Strip plugin more evenly and result in better-sounding and more consistent dialog compression.  This is a Good Thing™.

Along these same lines, clip gain is a very useful tool for dealing with highly dynamic performances.  If you’ve got a clip of dialog where the actor speaks quietly and then yells just a word or two, you can use clip gain to even things out.  Either raise the quiet part or lower the loud part (or both) to get a more even overall level before any audio enters your dynamics processors.  Once again this results in the ability to use more modest compression, which is always preferred.

The main thing to watch out for when using clip gain in this way is wild swings in the noise floor of your dialog.  Any gain you apply up or down will bring the noise floor up or down along with it (of course), so be careful not to boost things so much that the background noise can be easily heard pumping in and out.

Clip gain is a welcome addition to Pro Tools, and turns out to be a hugely beneficial tool for mixing.  Take advantage of it!