User Manual BDL4211x57MenuName andSub-menusDescriptionAUDIOAdjust audio characteristics to suit personal preference:EXIT: Exit from this menu.TREBLE: Adjustable from 0 to 100.BASS: Adjustable from 0 to 100.BALANCE: Adjustable from 0 to 100.VOLUME: Adjustable from 0 to 100.SURROUND: Switch Surround Sound On/ Off.MUTE: Switch Mute On/ Off.