Apple TV 4 and Sonos Soundbar/Connect Amp

I just got a 4th gen Apple TV and its audio output is considerably lower than the previous model, as well as all other components ffeeding my Sonos Connect Amp and Soundbar. I'm using the same HDMI cable that the previous Apple TV used without issues, and nothing else was changed. Has anyone else experienced this? I'm not sure if there's a way to boost audio output from the Apple TV, and as it is, I have to ramp up the Sonos volume all the way to get decent sound. My other components (as well as the previous Apple TV) only need to come up to about 1/3rd of that. Any thoughts and help would be hugely appreciated. Thanks, all!