Apple Logic Pro 8 - Manual (Page 512)

512 Chapter 21 Editing Audio in the Sample Editor
 Values over 200% are not recommended with normalized files, because they will
have detrimental effects on the sound and its dynamics. They can also greatly
increase the required computation time. On non-normalized audio data, however,
even high values can be effective because the overall level is initially increased to its
maximum, without affecting the dynamic range.
Attack and Decay
These parameters control the steepness of the algorithm’s filter. Try values of 2 to 4
times the default, if the result sounds too digital or raw. This can happen if smaller
elements among the main events in the signal are boosted. As an example, the reverb
portion of a sound can become louder.
Using the Silencer
The Silencer consists of two component functions which can be used separately, or in
conjunction:
 Noise Reduction lowers the level of any noise in the signal, such as tape noise.
 Spike Reduction tries to identify and reduce signals such as pops or clicks.
You will probably use Noise Reduction more often than Spike Reduction.
To open the Silencer, do one of the following:
m Choose Factory > Silencer from the Sample Edit or menu (or use the corresponding key
command).
m Click the Silencer tab if another Digital Factory processor is visible.
Noise Reduction
The purpose of Noise Reduction is to reduce the noise components of the signal, and
also affect the main signal, particularly the high frequency elements.