Attack knob and field: Set the attack phase of the reverb. This affects either the volume or the density build-up time, depending on the chosen room type.
For the following room types the Attack parameter increases volume over time: Theatre, Dense Room, Smooth Space, Reflective Hall, Strange Room, Airy.
For the following room types the Attack parameter sets the amount of time it takes for the reverb to reach the maximum density value, determined with the Density knob: Room, Chamber, Concert Hall, Synth Hall, Digital, Dark Room, Vocal Hall, Bloomy.
Size knob and field: Determine the dimensions of the room. Higher values correspond to a larger space.
Density knob and field: Adjust the density of the early and late reflections simultaneously, depending on room type.
Predelay field: Set the time between the start of the original signal and the arrival of the early reflections. A short predelay setting tends to push sounds away and longer predelay settings tend to bring sounds more to the forefront.
An extremely short predelay setting can color the sound and make it difficult to pinpoint the position of the signal source. A very long predelay setting can be perceived as an unnatural echo and can divorce the original signal from its early reflections, leaving an audible gap between them. An optimal predelay setting depends on the type of input signal—or more precisely, the PDF
Control Surfaces Support Guide: PDF