Apple Logic Pro X - Manual (Page 459)

Chapter 15 Advanced edit features 459
Trim or silence audio files
You use the Trim function to edit areas of the audio file that are not selected. It’s useful for
removing unimportant passages—generally silence—from the start and end of your audio files.
Trim can also be used to remove portions of audio files that are not used by regions.
You can use the Silence command to set all amplitude values to 0, rather than removing (with
Cut, Delete, or Trim) all data from the selected area of an audio file. This function is generally used
to silence unwanted background noise in quiet passages.
Trim all unselected portions of an audio file
m Choose Functions > Trim from the Audio File Editor menu bar (default key command: Control-T).
Important: Make sure the areas you are about to trim (delete) do not contain any regions that
you may need. Regions outside the selected area will be lost. Portions of regions that fall partly
outside the selected area are also removed, resulting in a length reduction of the region. If any
such regions are being used in the main window, a warning dialog will give you the option of
canceling the Trim operation.
Silence the selected area of an audio file
m Choose Functions > Silence from the Audio File Editor menu bar (default key command:
Control-Delete).
Set audio file levels
You can use the Change Gain command to change the level of an audio file in the Audio File
Editor. Typically used on an entire audio file, this command can also be used to boost portions
of it.
Raise or lower the level of the selected audio file (or area) by a specific amount
1 Choose Functions > Change Gain from the Audio File Editor menu bar.
2 Choose your settings in the Change Gain dialog:
•
Set the required level change in the Change Relative fields by clicking the up or down arrows,
or by directly entering values, in either field. You can use the percentage or decibel field to
indicate the amount of increase or decrease you prefer.
•
Click the Search Maximum button to search for the peak level. This automatically sets a
value that is used to alter the level of the audio file. The Results in Absolute fields display the
maximum level that will be achieved by changing the gain—by the amount shown in the
Change Relative fields.
3 Click Change to perform the gain change.
Important: You should never make a gain change that results in a value over 100%, because this
will result in digital clipping.