Why do I get no sound on hd channels on home theater?

What are some good ways go get better vocals out of my home theater system, specially at lower volumes?

• I have a very 'open' family room layout. The distance from couch to the TV + Home theater is around 10 feet, and the room is open from behind the couch, and also on one of the sides. I have set up a home theater with B&W 685 system (http://www.bowers-wilkins.com/Speakers/Home_Audio/600_Series/685-Theatre.html). It has been calibrated using the microphone that came with the receiver. Overall, I am happy with this system, specially when watching movies, etc. However, while watching regular (hd) TV, I feel that I have to really jack up the sound to hear the vocals properly. I even configured the system so that the center speaker is louder than the rest. I make sure that the surround mode is correct (most hd channels are on dolby digital or pro logic). What would be some recommendations to get better vocals while watching regular TV? I am open to any recommendations, including changing the layout to upgrading the speaker(s) to adding another speaker in the mix. I would prefer to keep the overall volume reasonably low but still able to hear what people are talking about.

• Answer:

  A few things to consider would be the position of the speakers in relation to your sweet spot or where you sit the most.  You'll want to make sure your center channel is aimed directly at your ears, or better yet at the same level as your ears while you're seated in the sweet spot.  Also try pulling your front speakers out from the wall and spread them apart about 10ft if you can.  This will help with imaging and soundstage, (more with 2 channel, but home theater as well)  after you move everything, run the auto calibration on your receiver again and take a listen.  Like you did earlier you can always adjust the center volume up, or drop the level of your other speakers down.    If after all of that experimentation you still aren't getting a solid change in audio, you may want to consider a separate power amp for your speakers.  This will give you more constant, dedicated power for at least your front 3 speakers that should improve clarity and dynamics.