I just exchanged regular cable box for HD cable box. The tv still goes thru receiver and surround sound but volume is much lower through receiver. Volume is normal when I play tuner. Also, my DVD players have picture but no sound now. I have to turn on tv speakers to hear DVD. I have red white and yellow hook ups on tv, dvd players (2) and receiver. What did the cable company do??? I was working great with the regular cable box. Please help.