Why This Problem Happens:

The sound delay problem happens because Sonos speakers have to maintain a big buffer to make the audio playback smooth. Plus exchanging and processing data also take time. It’s a hardware and streaming protocol limitation that we can do nothing about. The audio latency is about 1 to 2 seconds, depending on the quality of your network connection and the type of Sonos device the audio is sent to. 

 

How to Fix It:

However, there’s a workaround for this problem that we found pretty effective. You can use a free desktop media player called VLC Player to play all your videos, and use the audio offset functionality ("F" and "G" hotkeys) to manually synchronize the video and audio. (If you don't have VLC on your Mac, you can click here to download a VLC Player for free)

 

For Local Video Files:

When playing a local video file in VLC player, you can delay the video quite easily with the “F” and “G” keys on your keyboard to keep it fully synchronized with the audio coming out of your Sonos speaker. 

 

For Online Videos:

VLC player also supports streaming videos from online sources such as YouTube or Vimeo, so that you can use it to watch your web videos, and sync the video and audio using the “F” and “G” hotkeys.