Hi there, @BBrinker71!
Welcome to the Roku Community! We’re thrilled to hear that you’re enjoying our latest Roku Backdrops feature.
Regarding your question about turning off the ARC-connected soundbar when using the Backdrops mode on the Roku Pro Series TV, this feature is not available at the moment. However, we appreciate your feedback and will be sure to pass it along to our Roku team for consideration.
For more information about Roku Backdrops, please refer to this How to use Backdrops on your Roku streaming devices | Official Roku Support.
Thank you for being part of our community!
Best regards,
The Roku Community Team
Mary E.
Roku Community Moderator