A:Answer Yes you can connect a Home Theater System, an external receiver, or Soundbar to the Optical Digital Audio Out or to the HDMI ARC port on the LG UHD 70 Series 70 inch 4K HDR Smart LED TV, Model # 70UN7070PUA for surround sound. You can also set the Sound Mode Settings in the TV to enjoy an immersive soundscape with the virtual multi-channel surround sound effect...^IFV