Press Func button repeatedly to change input mode. Press Optical button to move input directly to Optical mode. Pressing the EQ button will allow you to change the Treble / Bass / Subwoofer level to your own prefernce. Mute button. Sound Effect allows you to change to different sound profiles and effects. Repeats USB content on a loop. Back to previous. Play or Pause content. Forward to next. Stop content playing. Switch on or off DRC (Dynaminc Range Control). Enhances clarity of sound even at high or low volumes. Night mode lowers volume and bass levels to create a more ambient sound. Automatically adjust the volume to the middle volume settings. AV sync allows you to customize the synchronization of Audio delay. Sleep function automatically powers down Sound Bar after a user set amount of time. This unit automatically turns on by an input source : Optical, LG TV or Bluetooth. Folder + & Folder - allows to move between folders when playing back via USB. Reveal more information on source file content.