As from 81.2 my LG Soundbar should be supported on Home-Assistant, but in my configuration it’s not vissible as a device. It sort of is as a Cast Device (BuiltIn Audiocast)
In the Debug Logs i see this
2018-10-31 14:41:17 INFO (MainThread) [homeassistant.loader] Loaded media_player.lg_soundbar from homeassistant.components.media_player.lg_soundbar
2018-10-31 14:41:17 INFO (MainThread) [homeassistant.components.media_player] Setting up media_player.lg_soundbar