One of the most powerful automation features that used to be reserved for Pro Tools HD systems is Trim Automation.  Avid has finally brought this fantastic feature to the masses with Pro Tools 9 (with the Complete Toolkit, that is).

Trim automation allows you to apply a relative change to your existing volume automation.  Let’s break down exactly what that means.Say you’ve got a very dynamic passage of dialog, and you’ve already performed some nifty fader moves to get it playing smoothly.  Now let’s say that in playback the client asks you to raise the dialog for the entire scene.  You could re-mix the whole thing,trying to replicate your moves while making everything a bit louder overall.  You could increase output gain on the EQ plugins that you’ve inserted on each track.  You could even adjust the level of your dialog chain’s fader (this is the method I least recommend).

Or you could choose the most graceful option, and put those dialog tracks into trim!  To do so, click on a track’s automation mode selector and choose trim from the pop-up menu (it’s the bottom option).  A check will appear next to the word, and the automation mode selector will be hi-lighted in yellow.

You can now place the track into the automation writing mode of your choice (write, touch, or latch) and create some trim automation!  This, when combined with Latch Prime & Write To Next Breakpoint, is a terrifically powerful way to make updates to your automation.  As an example, here’s a track with some volume automation that’s been put into trim automation:

Now start writing some trim automation:

Now check out the relative change that has been applied to the original automation:

Basically, the new trim automation was summed with the original automation to create the result.  If the trim move we added is a positive dB value, the resulting automation goes up.  If the trim move we added is a negative dB value, the resulting automation goes down.  And of course, as with the above example, you can do both in a single pass.

Clearly trim automation is a very efficient way to update your mix, and another reason why Pro Tools is Awesome!