Trueplay will make the setting, or you can manually adjust it in Settings > System > (room name) > Surround Audio > Surround Distance.

To keep the speakers in sync for TV audio you ideally need to ‘bond’ them to the Sonos HT device - only a pair of compatible ‘matching’ speakers can be bonded for this purpose. A single device cannot be used in this type of setup.

When bonded, the HT speakers (main player and surrounds) communicate over a fast 5Ghz ad-hoc wireless connection and the HT main player (the Beam) will automatically handle all the timing issues and it’s also best if you are able to TruePlay tune the room for your chosen listening position.

Any Sonos speakers can be ‘grouped’ (not bonded) together too, So you could group the Beam with your Play:1, or vice versa, which is fine for music playback purposes and the player that you begin the grouping from, will act as group co-ordinator and keep all the grouped players in sync across the network.. but if you ‘group’ the Play:1 to the Beam and then try to play TV audio you may (likely) experience a minimum audio delay of 30ms, or higher, between the speakers and that ‘may’ cause an echo when both are positioned in the same room.

There are some tools in the Sonos App "Settings/System/sBeam Room Name]’ to help try to bring the grouped speakers into sync.. see the "TV Dialog Sync” (slider bar buffer adjustment feature) and ‘Group Audio Delay’ options which you can perhaps research further on this site.   

Although note that some attempts to buffer/adjust the TV audio may cause the listener/viewer to sometimes experience lip-sync issues with the TV on-screen video.

Hope that information assists.