I've searched online, contacted Now TV over chat and still not clear. Current Help page states Boost enables 5.1 through Chromecast Ultra & 3rd Gen but what about Chromecast for Google TV? (this replaced the Ultra which is no longer even sold). I've had endless headaches getting 5.1 to work recently via Chromecast built in (new Phillips smart TV with Google TV installed). Thing is it WAS working recently and then when i had to reinstall the app I just get stereo. The app doesn't give me a 5.1 option in the settings.
Now TV has decent content but the app, streaming experience and quality are not up to par with Netflix, Prime, Disney, Apple etc (I use them all and they all just work: 5.1, 4K, Dolby Atmos/Vision/HDR and so on)
To select surround sound:
If I’m being honest, I have no idea as my devices have the native app which support 5.1.
Assuming you already have said devices, you can always take out the free trial for boost and cancel if it doesn’t work as expected. Otherwise it’s nothing lost.
Just make sure to cancel before the 7 days of it doesn’t work otherwise you’ll get charged £5.
5.1 audio on Chromecast can be a bit of a minefield and not just in relation to Now , but other services as well, especially when dealing with the Chromecast functionality which is built into TVs or other screening devices that run android/Google TV. As these devices are classified as Chromecast built in devices.
Typically, in my experience, Chromecast built in does not support 5.1 audio. This is almost certainly why Now makes the distinction of Chromecast third generation and Chromecast Ultra dongles supporting 5.1 audio. Unfortunately I haven't tried to see if 5.1 audio works on a Chromecast with Google TV as I don't currently own one
That being said, when I checked the now mobile app recently. I could not find the setting in relation to 5.1 audio for Chromecast as the setting used to be available in the app, regardless of whether you had a 5.1 compatible Chromecast on your network or not, but it's possible this might have changed.
Thanks for the detailed reply. I agree the option to select 5.1 was there before in the app. One comment on Chromecast and 5.1... Every version of Chromecast I've used has allowed 5.1, including built in. The only issues I've ever had have been with Now TV.... Netflix, Prime, Disney, Apple TV+ all play in 4K, HDR, 5.1 via Chromecast built-in.