To enable THX mode there are directions here for one-for-all remotes and Harmony remotes (I used a Harmony): http://openlgtv.org.ru/wiki/index.php/Access_hidden_service_menus_/_modes The password to access the service menu is 0413 and must be entered using the original LG remote. Once you've accessed the service menu go to 'Tool Option 3' and change both the 'THX' and THX Media Director' options to '1'. You will now have THX Cinema & THX Bright Room settings under your picture modes - all picture settings other than Trumotion and Local dimming are locked when you use these modes. You will also find a THX Cinema setting under AV Mode on the remote and in the Q Menu. Hope this helps.