How do I use a plugin on only part of an audio track in Digidesign Pro Tools?

There are two ways to do this:

The first way is to highlight the desired range of the audio track, go to Audiosuite, and run a plugin in non-realtime, which will semi-destructively process the audio. This method is quick and since it processes it immediately, it will not take up processing power in the future, and you will not have to worry about it. However, it does not offer the ability to change or bypass it (though you can remove the processed audio and revert back to the dry signal).

The other way is to setup automation of a real-time plugin. This method, while a few more steps, is completely non-destructive and offers flexibility of changing the plugin’s values at a later time. You can use ‘rubber bands’ to automate its gain, wet/dry ratio, on/off, level, or other attributes of the specific plugin you are using. Go to the Mix window, add the plugin, and go to the plugin’s window. Click Auto, highlight a parameter (or several), and click Add and OK. Go back to the Edit window and find the ‘Waveform’ next to a down arrow, click it and bring down the menu to select that plugin you added, and then select the parameter you wish to automate. It will now superimpose over the waveform display the value of the parameter selected (this is also how you automate volume and pan). Simply click on the line to make a point, and then that point is movable. Add more points to create more value changes, or smoother transitions. You can zoom in on the waveform view and get very accurate automation, down to the sample level. Benefits of this are the flexibility of easily changing it later, or bypassing it altogether. Disadvantages are that it is a little more work to get setup and it does use processor time whenever the plugin is active.

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