A:Answer I am not sure the HDMI connection offers the best digital sound quality over the digital optical cable and I know for a fact you do not need an ARC HDMI connection to get sound from this or any sound bar. I have my cable box connected to my TV thru HDMI, but I have the cable box connected to the same found bar thru the digital optical cable. This way, I get the best picture on the TV and the best sound on the sound bar.
If you want, or insist, on udon the ARC feature, you must first enable it thru the menu on your TV and then find out which of the HDMI connections on your TV s the ARC connection. On my TV, I have 4 HDMI connection, but the one labeled number 3 is the only one wth ARC. I don't use it nonetheless.