Word of warning for anyone looking at the Beam to start a 5.1 surround sound system, it will NOT work ideally for any streaming box except the Apple TV. I would suggest really doing your research and/or staying away from the Beam if you want a home theater solution.
The Beam does not support Dolby Digital Plus (DD+) and only supports PCM (poor quality) or Dolby Digital. Why does that matter? DD+ is the current standard. Dolby (the only thing Sonos support) sounds good but is hardly used anymore by anything halfway modern. PCM is the audio equivilent to standard definition TV.
DD+ is the de facto standard for streaming boxes and services. Hulu, Netflix, HBO and I want to say Plex support this standard and only this standard. Those services do not use Dolby Digital. To get Dolby Digital, that means the stream must be downconverted (transcoded) on the fly by either your streaming device or your TV before reaching the Beam. If you do not convert, you are forced to use the poor quality PCM.
Now here's the rub. Few TVs downconvert. If you have one that does? Great! You should have few problems. Thing is though today, few streaming boxes do as well. In fact, the only one that does that I can tell is the Apple TV 4K. The nVidia Shield does not, nor does any modern Roku device. The 2016 Ruku Ultra does, but the 2017 and 2018 models do NOT. Looking at Roku forums, a software update from Roku may have removed that option thus meaning no Roku converts DD+ to D.
I can not believe Sonos is selling a device, geared for home theater, that does not support what is a very common standard. Every single streaming device support DD+ along with all the major players including Netflix and Hulu. It is THE standard, yet Sonos does not support it.
Keep this in mind as you're researching. I find it very disappointing, and will be returning my Sonos products.