What connections does the Bose accept, hdmi? If so, connect the hdmi from the Bose to Arc Hdmi probably Hdmi 3 on the roku tv. Go into the Roku tv settings> system> Control Other Devices(CEC)> Click on Search for CEC devices> The Bose should show up on the list.
Now try the volume on the roku tv remote.
Edmund Roku Community Streaming Expert
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