In our office i brought my old surround system form my home and we want to get 5.1 sound from all 5 speakers + sub. At the moment we only get sound from front left and right with the sub. My dvd player has AUX (red and white), hdmi port and optical port. We tried aux but it onlly got 3 speakers to work. Later we went and bought a hdmi cable with mini hdmi to go in pc and its still not working can someone hlep us ?