The HD-HDX Oxford Envolution from Sonnox is a frequency-dependent envelope shaper with separate transient and sustain sections to radically reshape the sonic envelope of your instruments or audio. Use the broader tilt mode or the more parametric-style focus mode to choose which frequencies are processed. Insert on a track, bus, or even master output to add presence/distance to drums, piano, guitar and any other percussive content. Boost sustain to make the ambience around a recording bloom, or cut it for quick and precise gating.