If you connect using the digital input, using ARC or eARC (essentially using a TV set that creates this type of signal), there would be no appreciable delay.

It’s when you use an analog input from another Sonos device (the Beam has no analog input) that a delay of the minimum of around 75ms is inevitable, due to the need to prepare that signal for playback in multiple rooms. 

Sonos hasn’t designed their speakers as ‘computer’ speakers. The Beam does not take a simple HDMI signal such as most PCs use. 

Getting an ARC or eARC signal from a PC is challenging. Probably the easiest way to remedy this is to either use an optical output from the PC (or from an HDMI switch) to connect to the adapter that ships with the Beam. Alternatively, an HD Fury Arcana could provide an eARC signal from a standard HDMI output. 

Thanks so much! So if I use optical output from my PC to the optical-hdmi converter that Sonos provides. There would be no appreciable delay as well? And 5.1 would be supported?

Yes, up to Dolby Digital 5.1, with no appreciable delay. I don’t believe DTS will be supported across an optical connection to the adapter. Which means some extra effort to ensure the PC is generating the correct signal. 

Note…upon reflection, I’m not 100% sure whether or not the adapter ships with the Beam, but it certainly can be purchased separately, if it doesn’t. Ah….just checked the box contents for the Beam gen 2, it is part of the package. 

I’m not sure why not, though I confess I’ve no personal experience with Sonos and DTS. DTS has been supported over S/PDIF for, well, decades. 

Certainly worth testing, especially with the release of the new version of S2 this morning that supports DTS. If it doesn’t work, you can back the PC off to Dolby Digital instead of DTS. Should be an easy test, given the setup.