Lip Sync Alignment Tool
Audio early or late? A lot of the time, checking lip sync means standing in front of a camera and counting while someone in the truck tries to decide which way it is off. This 90-second tool gives you something easier to read.
Put the video on a phone, hold the screen in front of the camera, and place the mic next to the phone speaker. Watch the output you are trying to line up and adjust the delay until the clicks land at zero with the white flash. That’s it.
Download the Original Video
Most of the time, YouTube is the easiest way to pull this up on a phone. The original MP4 is also available for places with unreliable internet or whenever you want to play the original 1080p60 file.
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Download the original 1080p60 MP4 directly from A2Sound. No checkout.
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This is the same full-quality file through the A2Sound Merch Store. Choosing this option helps support future A2Sound tools.
Use the phone’s built-in speaker rather than Bluetooth. Bluetooth can introduce additional delay before the signal reaches the microphone.
How to Use It
- Play the video on your phone at normal speed and full-screen.
- Turn up the phone volume. Avoid Bluetooth audio.
- Hold the phone where the camera can clearly see the screen.
- Place the phone’s speaker next to the microphone being tested.
- Watch and listen to the output you are actually trying to line up.
Every two seconds, the diamond reaches zero, the screen flashes white, and the click plays. Look at where the diamond is when you hear the click:
| Where the diamond is | What it means | What to do |
|---|---|---|
| Left of zero | Audio is early | Add audio delay |
| At zero | Audio and video are aligned | No change |
| Right of zero | Audio is late | Reduce audio delay |
Make an adjustment and wait for the next click. The test keeps repeating, so there is no need to stop or record anything.
What the Scale Is Showing
The big ruler is useful when the sync is way off. It covers ±30 frames. The smaller ruler is easier to read once you are closer and covers ±15 frames.
The video moves at 60 fps, but the rulers are calibrated in 30 fps frames. At 30 fps, one frame is approximately 33.3 milliseconds.
| 30 fps offset | Approximate delay |
|---|---|
| 1 frame | 33 ms |
| 3 frames | 100 ms |
| 5 frames | 167 ms |
| 8 frames | 267 ms |
| 10 frames | 333 ms |
| 15 frames | 500 ms |
Watch the Final Output
When checking the whole production path, do not stop at the camera monitor. Watch the final output after the picture and sound have gone through the switcher, frame synchronizer, encoder, recorder, display, or anything else that will actually be used.
The camera monitor can look perfect while something farther downstream is adding delay. Check it at the point that actually matters.
What the File Is Doing
- 1920 × 1080 progressive video at 60 fps
- Measurement rulers calibrated in 30 fps frames
- One 30 fps white-flash interval, displayed as two 60 fps frames
- Audio click aligned with the beginning of the flash
- 45 click-and-flash events over 90 seconds
Created by A2Sound.com. © 2026 A2Sound.
