An audience can forgive bad video. They’ll have a harder time forgiving bad audio. But if your audio just simply doesn’t match up to your video, then you’ll be eternally doomed (or get really bad feedback from your audience). So, how do you prevent this from happening? The simple answer is by synching up your audio to your video. There are a couple of different ways video editors can sync their audio to their video and we’ll be explaining them both in this article.

Why might you need to sync audio?

If you’re new to filmmaking or videography then you might be asking yourself, doesn’t the audio from my recording automatically sync to my video? Why on earth would I need to do this manually? Very good questions, if we do say so ourselves.  Most cameras will have a built-in microphone and when you record video the audio automatically records and syncs to that clip - which means you don’t need to do anything but copy that footage from your SD card to your machine and start editing! However, the built-in mics in most cameras are atrocious! For anyone looking to get clean usable audio that will not make your audience storm out of the room punching a drywall, you’ll need to use an external microphone. We recommend Rode microphones as we’ve used them ourselves and can vouch 1000% that they are nothing but aural orgasm-inducing microphones to capture your audio with.  

You can plug a point and shoot video-mic pro+ (or similar) into your camera and your cleaner audio will also be recorded directly into the camera. However, sometimes you might be too far from your subject to capture the audio clearly, or you might be wanting to record multiple people talking at once (during an interview) and you’re unable to connect multiple mics into your camera. It’s situations like these where we turn towards external recorders to plug our mics into such as the Zoom H4N (or any of their other incredible products). With external recorders, you can record from multiple microphones and have each recording saved on a seperate track (channel) so you can isolate it in the edit. Once you’ve got your incredibly crisp audio recorded to an external recording device, you’ll want to bring it into the edit to match up with your footage - THIS is where the need to sync your audio to your video becomes apparent. 

Plan for the edit

The best thing you can do during any on-set production is to plan for the edit. Everything you do can either facilitate or make your time in the edit harder. When you’re thinking about syncing your audio to the video in the edit, you know you’re going to need a sync point, a waveform indication on the audio and video file that is easy to locate and is unique, so you can quickly and effectively sync up your externally recorded audio to your video. A classic trick that is still used in the industry is ‘clapping’, or using something like a clapperboard to make a loud clapping sound which creates a peak in the waveforms on both the externally recorded audio and the audio that was recorded in-camera on that becomes attached to the video file.

Manually sync your audio to your video

You can manually sync the audio to your video by manually aligning the 2 audio files; the externally recorded one and the audio attached to the video. Once aligned, you can mute the audio attached to the video. There is however, a quicker and more accurate method of doing this:

Automatically sync your audio to your video

In Premiere Pro CC locate and select both the video file and the externally recorded audio file in the browser panel (NOT in the timeline).

• Right-click on either of the files and select ‘merge clips’.
• A pop-up will appear asking the user to select a synchronize point. Select ‘audio’.
• Rename the clip to something suitable (not obligatory) and hit OK.

This will now create a new file in the browser with synced external audio. You can drag this into the timeline and mute the video’s internal audio channel and just keep the secondary audio channel (externally recorded) and you’re good to go. 

This ‘merge clips’ function works more often than not but to really help Premiere Pro sync your audio to your video, we would highly recommend clapping really loud to create sync points when recording - at the beginning (and at the end) of your scenes.

Pluraleyes audio video sync plugin 

Before NLE’s such as Premiere Pro and FCPX had these sync tools built in, there were plugins that editors would purchase and install to help them automatically sync their audio to their video - Pluraleyes was the king of these plugins! Despite these features now becoming a native function inside NLE’s, Pluraleyes is still continuing to develop and sell their syncing software. If it’s something you’d want to consider you can check them out here.

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