Apple Logic Pro 8 - Manual (Page 510)

510 Chapter 21 Editing Audio in the Sample Editor
m Click the Groove Machine tab if another Digital Factory processor is visible.
Swing
This parameter is used to set the swing factor. At 50% there is no change—you will
generally achieve the best results with values around 55% to 65%.
Based on Period
You can determine whether the audio material should be edited (quantized) on the
basis of eighth note, or sixteenth note swing.
Down Beat Level and Off Beat Level
You use this parameter to determine whether the down beats (or off beats) in the
audio material should be raised or lowered. Positive values increase the level, negative
values reduce the level. Bear in mind that raising the level of normalized audio material
can cause distortions (particularly on the down beats, which are usually louder).
Corresponds with Tempo
If you change this value, you will set the project tempo at the current playhead
position.
To Bar Length
Use this parameter to define the length of the selected audio material in musical values
(bars, beats, divisions, and ticks).
Using the Audio Energizer
The purpose of the Audio Energizer is to increase the perceived volume of audio
material, while altering the sound as little as possible, and without causing clipping.
Digital distortion (which would be the inevitable result of simply increasing the level) is
avoided by using this algorithm.