Hi sox1033,
The HW-B650 Soundbar will indeed be compatible with the 55QN90B Samsung TV. We do recommend using HDMI as this will offer the best audio and user experience. The TV remote will automatically work and be able to control the volume of your Soundbar.
For finer adjustments of the settings of your Soundbar, you will still need to use the Soundbar remote.
~Samsung Solutions