Hi I installed a Hisense 55" 55A7100FTUK TV with an LG LHB645N surround system and then could not get consistent output from the rear speakers, especially on Freeview channels. The surround worked perfectly using the DVD palyer! After a lot of messing about I discovered that the default sound setting on the LG unit is 2.1 sound (why???) so what you have to do is select another option such as cinema or bass boost. From the home screen press the Sound Effect button and it will show what output a particular setting has, for example 2.1 or 5.1. You can then select a 5.1 option and enjoy some rear speaker action. Hope this helps.