Apple Logic Pro 8 - Manual (Page 290)

290 Chapter 12 Getting to Know Regions
To snap audio edits to zero crossings:
1 Click on the title bar of either the Audio Bin or Sample Editor to give the window key
focus.
2 Enable Edit > Search Zero Crossings (or use the Search Zero Crossings key command).
Note: The Search Zero Crossings option can be set independently for the Sample Editor
and Audio Bin.
Moving a Region Within an Audio File
You can also move an entire region within an audio file in the Audio Bin window.
To move the region area within the audio file:
1 Position the cursor over the center of a region.
2 When the cursor turns into a two-headed arrow, drag the region to the left or right.
Note: If you want to adjust the boundaries of the region without moving the anchor
(see next section), hold down Option during the operation. This applies to moving the
start or end points, as well as moving the whole region.
Editing the Audio Region Anchor
The anchor is the temporal reference point of an audio region. When you move an
audio region, it’s not the start point that is displayed in the help tag (as with MIDI
regions)—it’s the anchor point.
In many cases, the anchor should be placed on the amplitude peaks, rather than at the
start of the sound’s attack phase. A good example would be recordings of brass
instruments, which may take some time to build to a peak. Moving the anchor to these
peaks forces the region to snap to the grid of your arrangement, using the anchor as
the pivot point. The flexible zoom settings allow you to be as precise as needed, going
right down to the level of single bits, at the highest magnification factor.
As another example, to guarantee perfect synchronization between a one-bar drum
loop and MIDI regions, the anchor must be assigned to a well-defined musical point. If
the loop begins with a significant level peak (say a kick drum beat), set the anchor to
the point where the volume of that beat is at its precise peak.
Whenever you record audio or add an audio file, the anchor and region start points are
always at the beginning of the audio file. Moving the region start point also moves the
anchor, as the anchor can not precede the region’s start position.
Two-headed arrow cursor