New to the Siri Remote is the ability to control the volume of your TV without having to dig out the TV remote. The +/- buttons let you control the volume on your TV via HDMI as long as if you have an HDMI-CEC (Consumer Electronics Control) equipped TV – otherwise you might need to fiddle around in settings.
If you have an older TV, you can manually teach the Siri Remote to control the volume. To do so you need to go to Settings > Remotes and Devices > Volume Control. Now choose Auto, TV via IR (if it’s available) and if your TV is capable to accepting the connection you should be able to link it to the Siri Remote. If this isn’t an option, it’s still possible:
Go to Settings > Remotes and Devices > Home Theatre Control > Volume Control.
Select the Learn New Device. If you have the option Auto or TV via IR that means your TV does support HDMI-CEC so you can automatically set it up. If not, take your normal TV remote control and point it at the Apple TV.
Press and hold the Volume Up button until the on-screen progress bar is full. Do the same thing with the Volume Down button. Your Apple TV should recognise these Remote commands and program your Siri Remote accordingly.
Note, HDMI-CEC could be referred to as SimpLink, Anycast, EasyLink, Bravia Link, Regza Link, Aquos Link, Bravia Sync, CEC or a similar name ending in “Link” or “Sync in your TV set up. If you don’t see something likely in your TV’s menus, try searching Google for “[TV manufacturer] enable CEC.”