Apple Logic Express 7 - Manual (Page 288)

288 Chapter 11 Sample Editor
Functions
This section describes various Sample Edit window functions that are ideal for polishing
audio recordings. You can use these to add the finishing touches to your work.
Each of the commands only affects the currently selected portion of audio. If you want
to use them to alter the whole audio file, use the Select All function beforehand.
All of the functions described in this section are destructive, and change the files stored
on your hard drive. You can, of course, use the Undo function.
As the Undo function in the Sample Editor works independently of the rest of the
program, you can try out an edit in the Arrangement and make changes there. As soon
as you open the Sample Editor again (or bring it into the foreground), the Undo
function is available for the last destructive sample edit.
You are asked to confirm these functions as a safety measure. This confirmation dialog
box can be turned off by selecting Audio > Audio Preferences > Warning before process
Function in Sample Edit (Menu).
Data altering processes can be cancelled while underway by pressing Command-
period. The audio file will be retained in its original state, even if it appears that a
portion of the editing function has occurred.
Normalize
Normalization is a process that raises the maximum level of a digital signal to a certain
amount—typically to its highest possible level, without introducing distortion.
Normalizing is activated by selecting Functions > Normalize.
This is done in the following way; Logic finds the point with the highest volume (
−
x dB)
in the currently selected audio, and determines how far this is from the maximum
possible level. The level of the whole selection is then raised by this amount. The
dynamic balance of the audio passage remains unaltered—it merely gets louder.
The start and end points for the section being normalized should generally not fall
within a continuous section of audio, as this will result in abrupt increases in volume
after normalization. The start and end points should therefore be located in sections
that also contain pauses. Occasionally, you should remove any unwanted, audible
noises that fall in musical gaps with the aid of the “Silence” function.
Change Gain
You can use Functions > Change Gain to raise or lower the level of an audio passage by
a specific amount.
A dialog box appears onscreen, allowing you to set the required level change in
percent (Change relative:) or decibels.