i'm new to surround sound and i'm trying to get the best out of what i have but need some help with understanding "Sound Field Programs." for example: Dolby Digital, DTS, Pro Logic, and many others. per the manual i did the following:
1) selected Input Source (DTV/CBL)
2) changed Input Mode to Auto

now, because i have done that, do i still need to select one of the Sound Field Programs? i've read the vague description they provide for these things, and i'm not sure which is best to use for TV, DVD, CD and Stereo. obviously whichever sounds best is the one to use. but am i selling myself short by not taking advantage of one of these Sound Fields?

i appreciate any tips you can provide.