Yes, the previous posts that you were recalling had to do with employing a "phantom" center with a 4.1 or 4.0 speaker setup. There's no special 4-channel or "phantom" setting to be made; by setting the sub "none" the .1 channel is automatically directed to the mains and by setting the center to "none", the center channel signals are automatically directed to the mains. The situation is different with regard to "down-mixing" 5.1 material to stereo. The player has to be set to whatever the particular manual calls it, as Alan mentioned, for the down-mixing to take place.
