Matt Petersen runs a lead vocal through UA's Lexicon 224 plugin, starting from the Smooth Vox Hall preset for that classic lush, long reverb tail.
He tightens the sound around the vocal using the mid decay slider to shorten reverb time, then rolls off harshness with the treble decay slider, which acts as a low pass filter on the tail rather than controlling its length.
Pushing pre-delay while lowering the bass and mid decay bands turns the same reverb into a slapback style effect. This thickens the vocal and gives it more presence without tracking a double.
The takeaway: multi-band decay and pre-delay aren't just tone shaping tools, they can pull double duty as a quick alternative to doubling a vocal.