I have the Yamaha RX-V671 and I am having trouble increasing the sound of voices in movies. How do I increase the sound of the voices? the background music and sound effects are all louder than the voices, I tried all the different cinema DSP scene modes, and cant get the dialog to increase in movies. I am using a 5.1 setup and when i go into dialog lift it comes up grayed out. What can do? Thanks.