Audio and video out of sync
The reason audio and video are out of sync is that video takes a lot longer to process. Audio is much faster and can therefore be sent faster to the TV or speakers. When we talk about high-resolution video material, this is further reinforced. So when an image has to be processed or edited by a TV or receiver or Blu-ray player (think of upscaling or filter effects for noise, etc.), the video can be somewhat delayed. The same applies to content you play via Netflix, for example, where the image is displayed via the TV and the audio via a linked soundbar or receiver. Several links in the system can cause delays.
Set audio/video delay
However, the solution is often more straightforward than you think. In most cases, one of the devices you work with (the TV, receiver, home cinema set, and sometimes Blu-ray player) has a so-called Lip Sync function. This function has different names, such as Audio Synch, HDMI Synch, Audio Delay, etc., but they all come down to the same thing; setting a delay for the sound so that sound and picture are synchronized again. This delay can be set in milliseconds, which seems little but has a lot of influence. There is no default setting that solves your problem. Often it is just trying out with which delay the image and audio are displayed synchronously. Some devices can do an automatic correction. You can find this in the settings menu.
With the advent of HDMI eARC – a long time ago – the problem of audio and video delay has mainly been resolved. This feature of HDMI itself ensures correct synchronization between image and audio. However, you do need equipment that supports this. So both the soundbar and the television or the receiver and the television.
More and more options exist for connecting soundbars and other speakers to your television, including Bluetooth. In some cases, however, Bluetooth can cause a delay. When television and (Bluetooth) soundbar or speaker are not coordinated – often by the manufacturer – there is a good chance that you will not get the image and the audio right. There is no simple solution for that either. We, therefore, advise against using Bluetooth if you want both image and audio unless the manufacturer advertises a Bluetooth connection specifically for this purpose.
Unfortunately, there are other reasons why image and sound are out of sync, which are difficult to determine in advance. For example, various image techniques, such as filters and motion handlers, can influence this problem. Disabling these extra image editing options one by one might solve the problem. In addition, you can try to limit the looping of the signal when a delay in image or sound is a significant problem. Then connect components directly to the television as much as possible. In addition, receivers with a room correction solution can sometimes cause a delay when this function is enabled. Do you have a receiver with room calibration active, and do you suffer from lip sync issues? Try turning this feature off.
Additional tip; If you watch via streaming services and suffer from lip sync issues, it may help to restart the streaming service.