Hello
I hooked up a sound bar to this tv and it works great. I used an optical connection from the tv to the sound bar. My sound bar is not a Roku one but I am sure you can connect the Roku sound bar in the same manner. I also connected a Roku Ultra streaming device to the tv using an HDMI cable. You can connect your Roku device in the same manner. If the Roku unit you want to connect to the tv is a combination sound bar and streaming device it would connect in a similar manner. I am sure the sound bar and streaming devices would have a manual that tells you how to connect them. I hope this information has been helpful.