How To Correct Audio/Video Synchronization Problems in Home Theater

TV With Home Theater Speakers
TV With Home Theater Speakers. Image provided by Getty Images - imaginima -GoodLifeStudio - Collection E+

Have you ever watched a TV program, DVD, or Blu-ray Disc movie and notice that the sound and video don't match?

One of the problems in home theater is the issue of audio video synchronization. In order to have a good home theater experience, the audio and video have to match-up.

However, what sometimes happens is that you may notice that the audio soundtrack is slightly ahead of the video image, making when watching a high definition cable/satellite program or upscaled DVD or Blu-ray Disc video on an HDTV or video projector.

This is especially noticeable on close-up images of people speaking. It is almost as if you are watching a badly dubbed foreign movie.

The reason this occurs is that audio can be processed a lot faster than the video, especially high-definition or 4K video. High definition or 4K video takes up a lot of space and takes longer to process than even the new high definition audio formats or standard resolution video signals.

As a result, when you have a TV, video projector, or home theater receiver that does a lot of video processing to the incoming signal (such as signals that are upscaled from standard resolution to 720p, 1080i, 1080p, or even 4K), then the audio and video can become out of synch, with the audio arriving before the video.

However, there are some cases where the video may be ahead of the audio.

Audio Video Synch Correction Adjustment Tools

To solve the problem of out-of-sync audio and video, there are tools available in the operating menu on many newer TVs and home theater receivers referred to as either "Audio Sync," "Audio Delay," or "Lip Sync." Some Sound Bar systems also have a variation of this feature.

Regardless of the terminology used, what these tools all have in common are settings that "slow down" or delay the arrival of the audio signal so that image on the screen and audio soundtrack match. The settings offered usually range from 10ms to 100ms and sometimes up to 240 ms (milliseconds). In some cases, the audio delay may be offered in both positive and negative terms just in case the video is ahead of the audio.

Although settings based on milliseconds seems minuscule in terms of time, a 100ms change between the timing of the audio and video can be very noticeable.

Also, if you are using a home theater receiver that features Audio Return Channel via HDMI connection, you may have the option to set this function so that AV synch can be corrected automatically or manually. If you have a home theater or HDTV that provides this choice, try both options and see which one gives you the most consistent correction result.

One additional thing to try is to turn everything off and reconnect your audio to your home theater receiver and the home theater receiver to the TV. Turn everything back on and see if everything resets.

Possible Audio and Video Connection Solutions

For DVD and Blu-ray disc players, another thing you can try is to split your audio and video connections between the TV (or video projector) and home theater receiver. In other words, instead of connecting the HDMI output of your Blu-ray Disc or DVD player to a home theater receiver for both audio and video, try a setup where you 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.

More Info

If you find that the tools or audio/video connection options available on your home theater receiver, sound bar, TV, or video projector don't solve this problem, definitely contact tech support for your components.