Are the Symfonisk being used as surrounds, or are they grouped with the Beam?  If grouped, then the delay will always be there due to the need to buffer the audio to be sent over the 2.4 GHz Wi-Fi.  If they were set up as surrounds, there is no delay because surrounds use a dedicated 5 GHz direct link that reduces lag, but is not suitable for groups because it doesn’t go through walls/floors as well as 2.4 GHz.

Thanks for your quick answer!

I cannot use my symfonisk as surround as both are different (1 Table Lamp & 1 Speaker).

I had to group all 3 devices…

But why isn’t there any delay when I’m doing it directly through hdmi from my tv to the Beam?

It’s only when using the optical converter…

There are no wall, it is on a open room with very good wifi as the wifi router is in the same room.

There is a lag for TV content no matter what you use.  Try it again, you will hear it. 

Thanks I will try it once again…

So, my only solution to have my output synced to all speakers (incl Beam) would be to use a Sonos Port?

No.  Any device grouped with a Beam/Arc/Amp will experience a delay when playing TV sources.  Only surrounds/Sub that is bonded as part of the room will not be delayed.  

I’m not speaking about TV source, but the other device I wanted to connect through optical to hdmi converter.

I wanted to connect a turntable with external mixer…

If I connect this mixer rca output to a Sonos port as rca input, all speakers should be synced, no?

Anything coming into the HDMI will be be delayed on grouped speakers because it is assumed the HDMI is being used for video.

A port is the correct device to use for a turntable.  

Another way to look at it is that anything connect to the aux input of the Port/Amp/Five will be delayed everywhere in order to allow proper syncing everywhere.  If you were to hookup a TV to the aux input for example, you’d end up with lip sync issues.