If you're experiencing audio delay issues, read this

Sonos can only play a sound as quickly as it is handed the sound on a digital input. All analog inputs are subject to the 70 ms delay for buffering that Sonos requires. 

It is indeed unfortunate that there are many TVs that apparently can’t pass through an HDMI input without processing and delaying that input. 

Hi Bruce, sorry you’re right I didn’t make it clear, having read through this forum thread (and countless others) I completely agree it doesn’t seem to be a Sonos problem at all. In fact it seems to be somewhere between TV manufacturers and, in my case, Xbox. As all my media comes from the Xbox, I’ve opted for the optical adapter solution which has completely eliminated the problem.

Worth noting, I was still able to pair my TV remote for volume control via the Sonos app. The only real caveat of using optical over Arc is the loss of TV control via Google Assistant or Alexa. Neither of which was a deal breaker for me.

Ah, understood. There are many people that want to point the finger at Sonos. While Sonos does have some limitations, this isn’t one of them. 

Yea, optical only travels one way, so the Sonos can’t communicate back up the line to tell the TV what to do. Probably why the system is called HDMI-CEC, and not Optical-CEC :)

Eesh

Have the sony x900f and experiencing noticeable lag with ARC and optical..

Currently have it setup via optical as I didn't want to lose one of the enhanced hdmi ports on the back of the TV.. Inbuilt apps work fine with the exception of Disney plus which only outputs stereo for some reason, but the sky satellite box and xbox (was aware of the xbox problem) have issues with the sound being after the video..

Am I correct in thinking that an optical switch would alleviate these issues, I guess the problem then is that optical won't carry dolby digital plus so you'd have to make sure each of your input devices have an audio setting to output just plain dolby digital correct? 

Still new to all this..

Edit : purchased the following from amazon and hoping it solves my issues:

https://www.amazon.co.uk/dp/B01A89OEUY/ref=cm_sw_r_other_apa_i_hcbUEbEPYNQCD

Hi

I have the same issues on my Panasonic. I have connected all external sources to the Beam using optical via a switch and picture and sound are perfectly in sync. You have to make sure that all sources output DD 5.1 only. 
 

Hi, my turn to complain ahah. I have a Philips 43PUS7354 and a Sonos Beam which works perfectly while watching content from apps inside the TV (Kodi, Netflix, Amazon Prime Video...), but when I use a PS4, there is a delay in audio of something between 0,5 to 1 second, which is very annoying, specially in FPS. I’ve set my TV settings to “Multichannel” output and my PS4 to “Bitstream (Dolby)”. The sound is great with 5.1 output but with a delay. If I put the PS4 to “Linear PCM” and/or the TV to “Stereo”, then there is no delay, but it’s much less immersive… I tried pretty much every combination (HDMI or Optical), and if I connect directly the Beam in the Optical output of the PS4, I get 5.1 and no delay. So there’s definitely something in the processing by the TV that delays audio. 

I have an hypothesis : when the Beam is plugged into the PS4, the Beam tells “I want DD 5.1” so the PS4 decode the audio, encode it in the right format and passes it to the Beam. With a TV in the middle, the PS4 decode the audio, encode it to whichever format the TV accept (and it can accept a lot), which is then decoded by the TV and reencoded in DD 5.1 to be send to the Beam. The extra process could explain the delay, which could depend on the power of the TV. 

I could be totally wrong on this, but if it’s true, there is no viable solution, except asking Sonos to support to support more format (DTS, Dolby Digital Plus) or asking TV manufacturer to put an option to manually set the audio format the TV can accept through its HDMI ports. 

Since the Sonos effectively plays the audio information handed to it as quickly as possible, it sure seems like the issue is upstream from the Sonos.

I have a Marantz NR1510 AV Receiver and don’t experience any audio delay or audio sync issues.  What is it with these Sonos soundbars that cause these audio sync issues?

I briefly owned a Beam and returned it after having audio delay and not wanting to deal with optical switches, etc..  I currently have a Sonos Arc on pre-order and am hoping it doesn’t have the same audio sync issues as the Beam I tried.

I’ve tested to unplug the beam, and by passing Bistream Dolby from the PS4, there is also a delay in the audio from the internal TV speaker. This means that the problem is the TV processing audio coming from HDMI sources causing the delay. So if there is a delay with the Beam, the Arc should also experience the same issue… I’ve read a lot about this and it seems that many TVs have trouble to pass audio from one HDMI source to another, inducing a delay. 

Agreed. In every case with a solution, it has been the processing / delay caused by the TV. Bypassing the TV’s audio stream has resolved the issue, which certainly relieves any responsibility from Sonos. The challenge then shifts to the handling of data from smart apps in the TV.