Audio de-syncs after manually syncing and merging

[spencer_6843]

We've all had the experience where Premiere couldn't auto-sync audio and video, and so we switch the timeline to Audio Time Units and get to nudging. (I've also recently learned that you can use a multi-camera source sequence to auto-sync and merge audio and video). That is only where my problem begins.

Once the video and audio are "linked" together, either through merging it myself or via multicam or nesting, THE AUDIO IS NO LONGER ALIGNED! This is after Premiere supposedly aligns the audio by its exact waveform, or I do it manually by eye.

I've tried switching the timeline back to frame count after aligning via ATUs, trimming the video and audio,  and then merging, and it still happens.

Here's an example of auto-synced multi-cam on my timeline. This is a clap, and the de-sync creates a very audible clap-clap.

Here's an example of a manually synced & merged clip, placed back into the timeline: 

Again, the clap very distinctly sounds like a clap and a half because of the de-sync.

hardware / software specs:

• Running Premiere Pro 25.5.0 (Build 13), but I've experienced this on versions prior
• Macbook Pro M2 Max, using Ventura 13.2.1
• Video is 2160x3840 (vertical 4K), 23.976 FPS, 48 kHz 16-bit stereo audio. Recorded on Sony a7S III in XAVC-S at 4:2:2 10-bit
• Audio is a separate track at 48 kHz 32-bit float mono, recorded using a Rode Wireless PRO lav mic. You'll see in the screenshots, I've mapped the audio into duplicate L/R stereo channels, but this seems to have had no impact on the sync issue either way.

I really don't know what to do about this. I've been having this issue with Premiere for 10+ years and a fix has never been made for it. It's like the program is overriding where I place the audio on the timeline. Please help.

[R Neil Haugen]

Wow, that's a total bummer. But also quite puzzling ... I've been using Pr for over a decade, with a ton of both Multicam and manual syncing, and never had this happen.

So I'm totally puzzled ... the only differences I see is that you're on Mac, and the sequence was vertical. Which shouldn't cause a problem one would think. Huh.

@PaulMurphy ... any help you could offer?

[PaulMurphy]

The way Audio Time Units work in Premiere Pro can be a bit unintuitive. When you nudge an audio clip using Audio Time Units (ATUs), its position is maintained with sample-level precision—but only until the clip is moved or edited as part of a video selection. Once that happens, even using Edit > Undo won’t restore its previous ATU-aligned position.

This behavior is one of several reasons why merged clips are not recommended. They can often introduce sync inconsistencies, especially when precision is critical.

For a more reliable workflow, I recommend the following:

• Manually sync your audio and video within a Multi-Camera Source Sequence, using Audio Time Units.
• Do not adjust the synced clips after this point.
• Once you've locked in sync, add a sequence marker at that sync point within the multi-camera source sequence using Audio Time Units. This will give you a reference that retains its exact position even when you return to frame-based editing.

[spencer_6843]

Hi Paul,

Thank you for the detailed response. Would you be able to elaborate on this with either screenshots or a video?

I'm not sure what you mean when you say "within" a multi-camera source sequence, since my understanding is that a multi-camera source sequence is more like a merged clip and less like a sequence, in my experience so far. I'm also unsure how adding a sequence marker comes into play once those clips start getting edited and moved around.

Bringing this back up since I'm editing a similar video again and running into the same issue. Simply clicking "synchronize" never aligns the audio perfectly, so I am still having to nudge stuff around in ATUs, and need a reliable way to link them together once I've done so. Thank you for your help.

[R Neil Haugen]

Multicam and a simple timeline action of Merge or Sync are not at all the same things. In fact, it is normally recommended for all workflows that will need pass through to a sound person, that you never ever ever use Merge clips, as that dumps all audio metadata from the resultant 'merged' clip.

Multicams in Premiere are sort of in interesting thing, but they are very different from either merged or other 'normal' clips. 

[PaulMurphy · Accepted solution]

A multi-camera source sequence is actually much closer to a regular sequence than a merged clip.

Under the hood, it's just multiple clips arranged in a timeline. The key difference is how it's displayed when nested: instead of showing all tracks composited together (like a regular sequence), it only shows one track at a time—based on your multicam selections.

You can open a multicam sequence in the Timeline panel by right-clicking it in the Project panel and choosing Open in Timeline. This lets you view and adjust the individual clips inside the multicam sequence.

Any edits made inside this multicam sequence—such as re-syncing audio or adjusting in/out points—are reflected everywhere the sequence is used. So if sync issues pop up, you can correct them directly within the multicam timeline, and those changes will automatically apply across all instances where that sequence appears.

[R Neil Haugen]

I don't think a lot of users understand the difference between the right-click in the bin, "open in timeline" option and double-clicking a multicam clip or dragging a multicam clip to open it in the timeline. Different things happen each way. You kinda need to get a bit of practice doing each.

[spencer_6843]

Finally! Thank you!

Right-clicking on the multicam and selecting Open in Timeline allowed me to shift the audio clips as needed and save it permanently. This will save me so many headaches in the future. Really appreciate it.

Also, @R Neil Haugen is totally right -- a lot of the documentation surrounding multicam is unclear or unintuitive. It seems the whole multicam method is more of a hack than a solution anyways. I hope Adobe addresses this in a more straightforward way in the future (in my head, this is what synchronizing/merging should do, but clearly doesn't and evidently causes its own problems downstream).

[spencer_6843]

@PaulMurphy @R Neil Haugen One (or two) more questions:

1. Is there a reason why, when I'm in the timeline mode of a multicam sequence (after clicking Open in Timeline), I can't solo the audio tracks? When I try to solo a track, it just goes silent—with the audio meters still jumping around as normal.

2. Although you solved my problem, I am still confused by the use of markers that you suggested. Not sure exactly where those come into play.

Thanks y'all.

[spencer_6843]

@PaulMurphy @R Neil Haugen Ok one more question:

After doing the Open in Timeline fix, playback on my multicams in the source window are silent. I haven't changed any settings—just did the fix as stated above, returned to frame-based editing, closed the multicam sequence—and now, I don't hear audio in the source window. As soon as I drag it into my timeline, I can hear audio. What is going on?

Notably, this issue doesn't affect multicams I haven't fixed yet.

[PaulMurphy · Accepted solution]

This issue is most likely related to how audio is routed in a multichannel sequence. By default, each audio channel in a multichannel sequence is mapped to a discrete output—so if you're monitoring through standard stereo speakers, some channels may be inaudible.

To properly monitor all audio channels through your stereo setup, click the small "bowtie" icons located at the bottom of the Audio Meters panel. These icons let you solo individual audio channels for monitoring.

Tip: Hold Shift and click the bowtie icons to enable all audio channels at once. This will ensure you're hearing everything, even in a multichannel timeline.

[PaulMurphy]

Are you muting tracks inside the multicam sequence? This can cause them to temporarily lose their audio, even if you unmute them again. A restart of Premiere should bring the audio back.

To isolate individual tracks, I recommend disabling clips rather than muting. 

[spencer_6843]

@PaulMurphy The bowtie thing solved my issue with soloing tracks — I was just doing that to check which channel corresponded with which lav mic. Thank you!

However, the No Multicam Audio in the Source Monitor issue persists. Here's what I'm looking at:

When I playback a multicam in the source monitor, after messing with the multicam sequence, I no longer get any audio. Not just muted with visible audio meters like before, but no audio at all during source playback. I've tried restarting premiere, clearing audio cache, checked all the spots where I could've had it muted, and I can't figure out why this is happening.

[PaulMurphy]

Go to Preferences > Audio and make sure Sum multichannel outputs to mono in Source Monitor is checked.

If that setting is enabled and you're still not hearing audio in the Source Monitor, could you share a screenshot of:

• Your multicam sequence opened in the Timeline
• The Audio Track Mixer for that sequence

This will help clarify how the audio channels are being routed and monitored.

[spencer_6843]

Hi Paul,

I've double checked, and the sum outputs option is checked -- still no sound in the source monitor. Here's a look at my sequence timeline with the track mixer open:

[PaulMurphy]

Is it just that you don't hear it or are there no bars in the Audio Meters as well?

[spencer_6843]

When playing back in the source monitor, it is silent and there are no bars in the audio meters:

Even the little preview window has sound during playback:

I'm really lost on what's happening. Here's a video: