Hi All I need help with my sound bar. I have a Yamaha Yas 108, I connect amazon fire tv cube to it by HDMI in, then connect to my tv from HDMI out, I'm only getting 720P video output. The Yamaha YAS 108 says that the HMDi passthorugh is up to 4K. if I just hook my amazon fire tv cube to my tv I get 1080P, am I missing something?