how do I connect my HD decoder sound to my Lg HT903TA-A0 home theater system?

[Philip Tenzen]

Don't know were to start please help really need your help..

 

[americanaudiophile]

Your HTiB has aux (analog stereo input) and toslink optical inputs. The optical would be preferred if your "HD decoder" has that. More likely it would have 2 stereo RCA jacks for audio out. This would be fine for the aux in using the correct cable.