Just got a Yamaha 600 series receiver to complement my Klipsch tower spearkers. Want to expand this to handle not just music but movie sound/partial surround sound as well. I've ordered a center channel (Yamaha) speaker and will get a subwoofer too. Right now, the vocals with the TV on vary by TV channel, some sound ok while others are awful and you can't hear voices. Will the center channel speak solve this? Also, how important is it that I get a Yamaha subwoofer? (I was told to not mix-match too much with speakers, and have tried not too, but the Klipsch center channel and subs are out of my price range).