@HighDesertHighlander 

There‘s no need of a „special“ cable. A good quality HDMI 2.1 cable should do the job. 

The demands for transporting audio are much lower than for transporting images.

Thanks for the feedback! It’s a big help.

One reason why this is so messy is that there are two sets of audio pins in a modern HDMI cable. The regular, legacy setup normally sends audio from a player or receiver to a TV. The second set of audio pins (HDMI-ARC or HDMI-eARC), the “Audio Return Channel,” is designed to support TV Apps that need to send audio back to the receiver. Chips at both ends of the cable need to sort this out. The SONOS soundbars accept audio only on the ARC pins. Legacy TV and audio equipment does not support ARC or eARC. eARC is a newer format that supports the latest, premium audio formats.

An optical connection only supports legacy audio formats. DOLBY ATMOS cannot pass over the optical connection.

None of the cable formats had projectors, coupled to soundbars, in mind. Cable lengths in the 30-50 foot (or more) range are common in projector rooms. At about 15 feet regular cables start to run out of bandwidth. Carefully designed and installed cables can cross this 15 foot limit (at a cost). While unthinkable a few years ago, we now have schemes that can send HDMi-ARC and HDMI-eARC over network cables and even wireless. At this time the reliable schemes are often out of the customer’s cost comfort zone. Your ARCANA is a prime example of this. It’s a great problem solver, but at a cost. ARCANA has lots of very handy tricks. but its main use is to allow regular HDMI audio to cross over to the ARC pins.

Thanks @buzz. I have two new 20’ cables and an Amazon fire stick max on the way which will be located mid room, out of sight. One cable to the projector and one to the Arc after the Arcana. I’ve been experiencing an HDCP error on the Roku. The HD Fury help suggests either the Fire Stick or Nvidia. They say they don’t see many Rokus used in applications (with the Arcana I presume).