Detect and Lower Clipped Audio in Apple Final Cut Pro 6
ASSESS YOUR AUDIO
Examine your audio closely. Does it only have a few areas where it fluctuates sharply between being too high or too low, or is it consistently too high or low across the board? If the former, first mark the audio peaks and then keyframe audio levels. If the latter, try the new Audio Normalization and Gain control.
As you play back an audio file in Final Cut Pro, the red clipping indicator within the Audio Meter alerts you to poorly recorded audio, but it can’t pinpoint the exact location where the clipping occurs. The Mark Audio Peaks command can help you zero in on those hot spots by marking the specific areas of the video where the audio exceeds 0 dB on the digital scale.
SELECT CLIPS FOR PEAK DETECTION
For a single clip, select it inside the Browser Window. To check the entire sequence, make sure that all audio and video clips are unselected before you begin marking audio peaks. In this example, I have checked the entire sequence.
MARK AUDIO PEAKS
Navigate to Mark > Audio Peaks > Mark. Final Cut Pro will begin to analyze the audio. You can monitor its progress in the status window.
If you select a single clip for peak detection, you can see the markers in the Browser by clicking the clip’s disclosure triangle, and also in the Viewer when the clip is loaded. If you choose to search the entire sequence, the markers appear in both Timeline and Canvas windows.
If peaks are found, you are likely to find two types of markers. Areas with audio that spike sharply above 0 dB will have a conventional marker point, while areas which contain audio levels that are consistently over 0 dB will display a marker with a duration.
LOWER CLIPPED AUDIO
To turn on audio waveforms, go into the Timeline Layout popup menu and check Show Audio Waveforms. If you’re keyframing a single clip, double click to load that clip into the Viewer, and open the audio tab at the top of the window.
You’ll need to create multiple control points per spike or dip to adjust the audio. It might help to imagine you’re creating a hammock for each area that needs adjusting: one point before the area, one after, then as many points in the middle as needed to softly lower the clipped spot. Use the Pen tool or Option click around the problem areas on the red audio overlay to create each control point. If needed, control or right click on a point and choose Clear to remove it.
After you’ve placed your points, drag the middle point down to decrease the volume or upward to raise it. As you raise or lower the audio, a box appears, letting you know by how many decibels you are adjusting. Your adjustments are mirrored in both tracks of a stereo pair.
CLEAR THE AUDIO PEAK MARKERS
Go to Mark > Audio Peaks > Clear to remove the peak markers when you’re finished.
Lonzell Watson is an Apple Certified Final Cut Pro Professional and Certified Avid Xpress Pro user. He is the author of Final Cut Pro 6 For Digital Video Editors Only and the soon-to-be-released Canon VIXIA High Definition Camcorder Digital Field Guide, both from Wiley Publishing, Inc. He is also author of the upcoming Final Cut Express 4 Essential Training from
LONZELL SAYS KEEP IN MIND…
There is no substitute for acquiring the best audio you can while in production, but the audio cleanup tools can be a lifesaver if the possibility for a re-shoot is a no-go. An important thing to note here is not to rely solely on peak detection or the Audio Meter to tell you what audio may or may not be clipping. You can have audio in your sequence that doesn’t register as being clipped, but is distorted when you listen to it. Let your ears guide you and listen closely.
Tools Used: Apple Final Cut Pro 6