If you want to flatten the vocal performance, here's how to make a "lookahead" compressor in Pro Tools (others DAWs should have a similar workflow). This technique eliminates the slight delay between the signal and when the compressor kicks in, and allows you to have a "zero attack" compressor that can predict exactly when the vocal dynamics change. Set it up right and the compressor will perfectly follow the vocal, allowing you to use a bunch of compression with very little artifacts. It's also great because you can do it with any compressor, even an outboard one.
1. Duplicate the vocal track. If the vocal is spread out over multiple tracks, it’s helpful to consolidate or bounce a copy of them to a single audio track for the purposes of this technique.
2. Set the output of the duplicate/bounced vocal track to an available bus path.
3. Instantiate a compressor on the original vocal track and set its “Key Input” control to the bus path from step 2. Engage the compressor’s external sidechain if necessary. The compressor will now be triggered by the audio from the duplicate/bounced vocal track.
4. Nudge the audio on the duplicate/bounced vocal track backwards (earlier) in time by very small increments. The compressor on the main vocal track will now respond sooner, because it’s acting upon the time-shifted audio from the duplicate/bounced vocal track.
5. Shift the audio on the duplicate/bounced vocal track backwards (earlier) until the compressor on the main vocal tracks the vocal’s dynamics as perfectly as possible and the time-delay has been eliminated. Use your ears and the meters to find the sweet spot.
Voila! Super-tight vocal compression. You can do this with any dynamic-range processor to achieve "lookahead" functionality.
