Can someone help me disable the internal speakers when I'm using the apps? Everything works as it should when watching sources routed through my avr (Yamaha a720). It's when using the Vierra apps that I run into problems. I've tried using ARC and using optical, but sound continues to play through internal speakers. I once got it to play through both the internal speakers and the avr but I know that's not right. I know there must be a simple menu setting I'm missing, but I'm at a loss.