Create a Custom Silence Placeholder for Final Cut Pro

Using FFmpeg and Audacity

May 16, 2025 by cryan.com

I'm always looking for clever ways to simplify my Final Cut Pro workflow. Today's tip tackles an annoying quirk in Final Cut Pro: you can't set the default length of a gap clip.

If you need to insert a 5-second placeholder multiple times, you're stuck dragging that gap clip longer each time. Let's fix that - permanently - with a custom silent audio clip.

Create a Silent Audio File Using FFmpeg

Use this command in Terminal to create a 5-second silent WAV file:

ffmpeg -f lavfi -i anullsrc -t 5 -c:a pcm_s16le silence.wav

Explanation:

• -f lavfi: Uses libavfilter (virtual audio input)
• -i anullsrc: Generates a silent audio source
• -t 5: Sets the duration to 5 seconds
• -c:a pcm_s16le: Encodes using 16-bit PCM format (WAV compatible)
• silence.wav: Output filename

Want a different format? Just change the extension and codec:

ffmpeg -f lavfi -i anullsrc -t 5 -c:a mp3 silence.mp3

Creating Silence in Audacity (No Terminal Needed)

If you don't have ffmpeg installed or prefer a graphical method, use Audacity:

1. Open Audacity
2. If no project is open, use Command + N to create one
3. Go to Generate > Silence...
4. Set the duration to 00h 00m 05s 000ms or your desired length
5. Click Generate
6. Use Command + Shift + E to Export Audio
7. Name the file (e.g., 5-Seconds.wav) and Edit Metadata if you like

Why This Matters

Instead of repeatedly resizing gap clips, this silent file acts as a reusable, precision placeholder. It saves time, keeps your timeline clean, and gives you total control over timing placeholders - perfect for podcast intros, syncing edits, or planning space for VO recordings.