I am having gigabyte motherboard.It is having a 5.1 channel onboard sound card,so there is 3 socket to connect speaker at the back of the cabinet--2 front,2 rear& center and subwofer.Now if i connect 3 set of sterio speakers to the three panels I can get the 5.1 channel effect.Then what is the need of a home theater system?What will be the difference?Which wil be better?