Correcting Audio Video Sync Problems in Home Theater

This article explains how to fix audio and video syncing issues in your home theater system. When the audio you’re hearing doesn’t match the video you’re watching, it can be quite frustrating—and especially noticeable on close-up images of people speaking (thus the term lip-sync).

What Causes Audio/Video Sync Problems?

The most common reason audio and video gets out of sync is due to audio processing speed. Audio often processes a lot faster than video, particularly when it comes to 4K videos. High-resolution video files take up a lot of space, and as a result it can take longer to process a video signal than an audio signal.

If your receiver or display is set to do a lot of video processing to the incoming signal (such as upscaling), the audio and video can get out of sync, with the audio arriving before the video (or vice versa).

How to Fix Audio/Video Sync Problems

Depending on your TV, home theater receiver, or sound bar, the exact steps you take may vary. Furthermore, not all displays have the same features, so it's likely not every solution will be available to you with a single display.

1. Disable all of the video-processing settings on your TV, such as motion enhancement, video noise reduction, and any other picture-enhancement features.

2. If you have a home theater receiver performing video-processing tasks, disable all of the video-processing on this device as well; you might be adding more delay by setting video processing to occur in both the TV and home theater receiver.

3. If changing the above settings corrects the situation, enable each processing feature again until the audio and video gets out of sync. You can use this as your audio/video sync reference point.

4. If you are using a home theater receiver that features Audio Return Channel via HDMI connection, you might have a setting available to correct AV sync automatically or manually. If so, try both options and see which one gives you the most consistent correction result.

5. If curtailing the TV or home theater receiver's video-processing features doesn't work, or you need to have those features on, check the settings available in the operating menu on your display or receiver. Look for terms like Audio Sync, Audio Delay, and Lip Sync. Some sound bar systems have a variation of this feature, too.

   Regardless of the terms used, all these tools offer settings that slow down or delay the audio signal's arrival so that image on the screen and audio soundtrack match. The settings usually range from 10ms to 100ms and sometimes up to 240 ms (millisecond = 1/1,000th of a second).

Modify Your Connection Set Up

If provided settings and other tools don't solve the problem, you can also try modifying your connection setup.

For DVD, Blu-ray, and Ultra HD Blu-ray disc players, try splitting your audio and video connections between the TV (or video projector) and home theater receiver.

Instead of connecting the HDMI output of your player to a home theater receiver for both audio and video, connect the HDMI output of your player directly to the TV for video only, and make a separate connection to your home theater receiver for audio only.