The Arc (ARC is an HDMI CEC function) usually connects to a port labeled ARC or eARC on your TV set. It then broadcasts a ping to the CEC computer in the TV that it exists as an audio sink, along with what formats it can process. 

However, if memory serves, in the Arc’s box (see box contents in the sales page) is a Sonos optical to ARC adapter, which also restricts the signal to Dolby Digital at best, due to bandwidth limitations. 

I’m not sure what ‘fiber out’ is, or on what device it is. I stream Hulu on my Apple TV, which is connected to my TV via HDMI, and my Sonos Arc is connected to the TV’s ARC port. 

Thanks for the reply, Bruce. Yea I did do some quick research on the Sonos page for the Arc. Wish I did this when I ordered the system back on Black Friday. 

I have one ordered now so I’ll finish setting up all the new speakers hopefully next weekend. 

Not sure if my TV has the HDMI CEC port. I’d have to look it up. It’s maybe 3-4 years old.

Is HDMI-eARC as HDMI-CEC. Just check my TV and it has w HDMI-eARC port.

HDMI-eARC is the port you want to connect the Arc to.

Yes. eARC is newer and greater bandwidth, but also backwards compatible with ARC. From your perspective, they’re the same. 

Yea that worked. All hooked up and playing fabulous..

Thank Bruce...