Videos not using 5:1

[ViolentJ]

Why will non of my video clips, dvd clips etc play in 5:1? I've tried media Player, Winamp and VLC so it's not the player.

In fact they will only play out of the 3 front speakers.

Mp3's are find and use 5:1.

 

[CocoPops]

Because they are recorded in Stereo probably not 5.1