Question for Home Theater experts Trying to trouble shoot a muffled sound coming from my home-theater set up. (I haven't changed any settings in 4 years). Sony receiver, polk-audio 5.1 surround. U-verse box is connected component to the TV then component out to the receiver and the optical audio runs directly from Motorola cable box to Sony receiver (Sony STRDH700). (everything else is connected via HDMI) - Issue is only when watching programs from cable box/DVR (blu-ray & PS4 sound perfect) - First noticed it on The Voice, the audio quality is terrible. It's very muffled sounding...thought it was the channel (and/or program), tried different settings trying to force better audio mixing, switching from A.F.D Auto to movie and music settings. Commercials sounded fine, only The Voice on NBC. - Tonight, on ABC, watching CMAs...when hosts talk (or commercials) it sounds fine, but when the musicians start playing the sound ceases from the center channel and transfers only to the external speakers and it sounds hollow and echoey. I tried my other TV which just has a sound bar and it sounds fine (but that's not comparing apples to oranges). Any ideas for trouble-shooting? I can't even figure out where to begin. Very strange Moderator's Note: Links to external sites removed.