Ensure your Beam is connected to the eARC HDMI port on the TV, and set your TV’s output settings to Bitstream if available and ‘pass-through’ so your Apple TV’s sound isn’t processed by the TV on way to the Beam.

Also check your TV’s audio delay setting - it should be set at zero probably. 

It won’t be a Sonos issue, as that can only play what it is sent. It will be your TV primarily, then the Apple TV. Both have their own sound settings that must be correct.

Yes the Beam is connected with eARC HDMI port. I set the sync on bypass on my tv as well. It’s better now, but not perfect. On my tv there’s also something called DTV sound settings. It’s now on Auto. But the choices I have is:

• MPEG
• Dolby digital
• Dolby digital plus
• HE-AAC
• Auto

Should I set my Apple TV on Stereo mix out maybe?

You say it’s not Sonos. Well, I didn’t have problems with this before with other brands. I then used optical cable though. 

Are you certain the HDMI port is eARC and not just ARC? The specs I have found online suggest HDMI ARC? If so, that could be the issue. Another forum user the other day had sync issues with their Beam and LG which only had ARC. The eARC is often key in syncing on the Beam.

However, certainly try the different DTV settings and see. You can always go back to Auto.

Your Apple TV settings should also probably be as follows (under Settings - Video and Audio)

Audio Output - Receiver Speakers (all being well this will be shown already)

Audio Format - Change Format - Off 

Audio Format - Immersive Audio - Dolby Atmos - On

Audio Mode - Auto

But also under Video, ensure you have:

Format - 4K SDR - it sounds counterintuitive to have SDR but it makes sure all content displays properly, including the Apple TV menu, with HDR kicking in only when needed by ensuring the following is selected:

Match Content - Range and Frame Rate

HDMI Format - YCbCr

Chroma - 4.4.4

Matching frame rate additionally helps ensure the audio and video content match up.

Try these and see how you get on…

Thanks Rhonny, I will setup all these settings on my Apple TV and see if it gets better. 
 

Yes it’s only HDMI ARC and not eARC. Should I try using the included hdmi to optical adapter if I don’t get it synced?

Always worth a try. It’s not a permanent thing if it doesn't work but HDMI-ARC might work better with optical, especially as that’s how it worked best for you before.

The only thing to say is that I don’t think the Beam will produce Dolby Atmos over optical.

So perhaps try the Apple TV settings first, and see how that goes.

Ok thanks. I will try this with Apple TV first then. 
 

As you seem to be good at this I need to ask you another thing. I experience that the Beam has a very high difference when it comes to levels of speech and sound effects. The speech is kind of low and the music or sound effects gets very high. Too high I should say. Do you recommend any settings anywhere to avoid this?

On the Sonos app’s Now Playing screen when watching TV, tap the Speech Enhancement option which should raise the speech levels by enhancing the middle frequencies. See if that helps to provide a better balance of sound. 

There is also an option in the Apple TV settings where I can decrease the sound and music effects. But this is also nothing I needed to do before. Hmm. 

It’s also worth removing power to the tv and Beam, so the handshake is reestablished when power is restored. This has helped with sync issues according to posts on other threads. 

I did have all the Audio setups above in my Apple TV. But in the video settings I changed:

Match Content - Range and Frame Rate: ON

Chroma - 4.4.4

And then I also pulled the power plugs to everything to make the handshake again. And now the sync is back! :)

But I still think that the levels of speech and sound effects/Music differs too much  

Great on the sync!

re the speech - did you try the Speech Enhancement? (I appreciate you shouldn’t need to do that).

I think the ‘sound effects and music’ setting on the Apple TV is for the system sounds (eg menu transitions when opening apps) rather than tv content sound and music. ‘Reduce Loud Sounds’ though might have a positive impact for you. Worth a try.

One other thing to try in the Sonos app is under Settings - SBeam/room], and scroll down to EQ. Try toggling Loudness on and off to see which provides you with better sound balance.

Finally you should definitely run Trueplay if you haven’t already. This could solve all your sound balance issues in one go. 

I agree regarding the Speech Enhancement I’m the app. I tried that once. But I don’t like how it sounds. 
 

But I will try the Reduce Loud Sounds in the Apple TV settings and see what happens. And also see what happens with Loudness on or off. 
 

I have run Trueplay twice. But, not after pulling the plugs and restarted the systems. Maybe worth a try with a third session.  
 

Last, I’m thinking about turning the Atmos and 3D spatial sound off and only use in Stereo mode. Maybe this levels out the high and low volumes in dialogue and effects/music?

It’s a five second job so give it a go. if it doesn’t help, put it back.
It will only make a difference to content received in 5.1 or Dolby Atmos though. If stereo TV broadcasts are already still troublesome for sound balance, removing those modes is unlikely to help.
And it would be a shame to not use the Beam to its capability - you could have bought a much cheaper soundbar!

For the levels the option “Reduce Loud Sounds“ in the Sound settings on my Apple TV worked pretty well. Setting the app in “Night Mode” did almost the same job, but not as good. 
 

But, watching movies in 5.1 sound will get the Beam in very low volume compared to Stereo mixed movies. With och without the “Reduce Loud Sounds“ turned on. Shouldn’t the Beam handle a 5.1 movie?

Yes, it can handle 5.1 movies very well by creating virtual surround, just like it creates virtual Atmos for Atmos movies. There should be no reason it doesn’t sound good for these movies, especially with any sound reductions turned off (eg no use of Reduce Loud Sounds or Night Mode). And with any Dolby or Spacial settings turned on, and the Apple TV settings we discussed.
Is it not sounding good?