The project
Use two adjacent dialogue shots with extra recorded sound before and after the chosen picture ranges. The aim is to separate the moment the audience hears a change from the moment they see it.
A J-cut brings the incoming sound in before its picture. An L-cut lets the outgoing sound continue after the picture has changed.
1. Establish a clean picture cut
Create the two-shot sequence and refine the visual edit first. Listen to the original recordings around the cut. You need source handles for an overlap; the editor cannot extend a recording beyond the sound that exists.
Save a named version so you can compare the straight cut with the split edit.
2. Create the overlap
Select the relevant linked picture and sound and use the audio edit-offset controls to detach the intended audio boundary from its picture boundary. Work in small frame increments. Inspect the timeline’s lead or lag badge to understand the current offset.
For a J-cut, let the next speaker begin before showing them. For an L-cut, stay with the outgoing line while revealing the listener or next scene.
3. Check the transition
Play several seconds across the overlap. Listen for doubled room tone, clipped words, a sudden noise-floor change, or an unnatural pause. Adjust the boundary according to the sentence and reaction rather than choosing an arbitrary number of frames.
If both recordings contain the same sound event, check for an unwanted echo or phasey overlap.
4. Recheck synchronization
Watch visible speech and recognizable actions after the edit. An audio boundary change should not become an accidental source-sync shift. Review linked-selection behavior before subsequent trims.
Review your result
Compare with the saved straight-cut version. Keep the overlap only if it improves the viewer’s understanding or emotional transition. Subtle sound continuity often works better than a conspicuously long overlap.