Noam Wallenberg walks through frequency-specific dynamic control on vocals using a de-esser and the Waves C6 multiband compressor, showing how treating different frequency bands independently solves problems that broadband compression can't touch.
His first move is a low-shelf band to catch surges of low-end that only appear on certain sung notes. Rather than EQing the low end out permanently, the compressor only engages when those frequencies spike. A slower attack on this band lets the fundamental transient through before gain reduction kicks in, creating a perception of more low end even while compressing - what Noam calls "phantom low end."
On the high end, he builds two overlapping bands to target bright consonants across the 4k-16k range, going after the harsh moments that aren't necessarily sibilant S sounds.
The key move is using the gain controls on those high bands to boost presence. The gain is always on, but the compressor pulls it back during the loudest, harshest moments - so sibilants and bright transients get the boost reduced right when they'd otherwise become a problem. You get consistent presence and air on consonants without the S sounds turning harsh.