...there's as many approaches to HT and 'stand-alone' audio as cars on the freeway....
One can always opt for a better than average card in that 'puter in the closet that could 'do' 5.1 in a snap, yet be 'throttled back' to 2 or 3.1...decent distribution amp from PE, speakers as fit ears 'n budget.....
Input the flat screen and go...'puter can stream, Spotify, soundcloud....the world at your keyboard....freeware eq, even room correction....
I've been doing this for years....