if your TV does not support SPDIF (optical port) you should do it by HDMI with this adapter:
http://www.ebay.com/itm/HDMI-To-HDMI-VGA-SPDIF-5-1CH-RCA-1080P-Digital-Multi-channel-Audio-Decoder-/221952142653
it has a HDMI in port that will separate sound from video and will feed the sound to other...