There's a setting to turn off the TV speakers. p4 of the manual. Select External Speakers. There's also a setting for the type of audio that gets sent from the optical output. p3 of the manual. Try setting it to Dolby Digital. As noted in my previous post, most TVs only output stereo from external devices. But, give it a try and see what happens. If it doesn't work, and it probably won't, then you'll need to run audio from each device to the receiver instead of routing the signals through the TV.