Soundbar Samsung connection

[KMontanya]

I need help to connect a samsung soundbar HW-f355 TO A RCA led55c55r120q
is conected via audio cable but don't works i use to watch tv a roku 2

 

[batuchka]

Going thru the soundbar, tv and roku 2 manuals it seems the easiest way is simply pass video from roku 2 to TV via HDMI and pass audio from roku 2 to soundbar via analog?