Compressor

This MIDI compressor is used for evening out or expanding differences in velocity.

Threshold: Only notes with velocities above this value are affected by the compression/expansion.
Ratio: Sets the amount of compression applied to the velocity values above the set threshold. Ratios greater than 1:1 result in compression. Ratios lower than 1:1 result in expansion.
Gain: Adds or subtracts a fixed value from the velocities. Since the maximum range for velocity values is 0 to 127, you can use the Gain setting to compensate, keeping the resulting velocities within the range. Typically, negative Gain settings are used for expansion and positive settings for compression.