I've spent hours researching how to play a Netflix show, through Google Chrome Browser (on a Mac), through a Chromecast streaming device.
I then need to split the HDMI signal coming out of Chromecast to (A) HDMI visual signal to an EPSON projector, and (B) optical audio to a SONOS Playbar.
Couple keys for those having issues:
1. Every audio output up to the SONOS Playbar needs to be providing a "Dolbly Digital 5.1" signal. You need to backtrace all the way to your original source.
Here is what Netflix Customer Support wrote me:
DD 5.1 surround sound is not currently supported while streaming on a computer using Microsoft Silverlight or HTML5 (this refer to browsers of all kinds). However, it is supported in the Netflix app for Windows 8 and Windows 10.
Click the "Dialogue" box in the show/movie you're watching. Make sure it is set to "ENGLISH - 5.1"
Otherwise it won't work.
2. Your Chromecast device also needs to be putting out DD 5.1
-- I haven't tried to troubleshoot this step yet. TBD.
3. If you are converting your HDMI signal from Chromecast (or whatever else is your signal source) the Optical Audio Output needs to be DD 5.1
Here's one device on Amazon that seems to help make this happen:
I just ordered it. I'll let you know how it goes!