You can't connect them to each other, they can both be connected to the same tv, if the tv has hdmi-arc the ultra audio should be heard through the soundbar. And so no you do not have to use the apps on the soundbar and just use it for better sound. The thing is the ultra and soundbar respond to the same IR roku commands, so if you don't want conflicts be sure to use only wifi roku remotes. The ultra comes with wifi remote, and roku branded soundbar and streamber come with wifi remotes too. But the Walmart Onn Roku soundbar comes with IR remote that would control ultra and soundbar at the same time.
Edmund Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution." If you appreciate my answer, maybe give me a Kudo.
But the Walmart Onn Roku soundbar comes with IR remote that would control ultra and soundbar at the same time.
This problem can be avoided if you position the Ultra so that the direct line-of-sight IR remote can't "see" it. You can place something in front of the Ultra to block the IR, or cover the IR receiver on its front with opaque tape.
Roku Community Streaming Expert I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well. If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
Streaming Stick 4K+ 3821 | Streaming Stick+ 3810 | TCL Roku TV 43S245/C107X