2006 Mercedes SLK-Class Owner's Manual - Page 209

Controls in detail Audio system Adjusting treble Press O button repeatedly until TREBLE appears in the display. Returning sound functions to factory settings Press O button to call up settings menu in the display. Adjusting balance Press P button. BALANCE appears in the display. Press + or - soft key to increase or decrease tone level accordingly. or Press RES soft key briefly to reset treble tones to their center level. The radio switches back to the standard radio menu 8 seconds after the last soft key is pressed. or Press RES soft key briefly; the respective sound function is reset to its center level. or Press and hold RES soft key until RESET appears in the display. The sound settings for bass and treble are returned to their center level and the volume is set to a predefined level. The radio switches back to the standard radio menu 4 seconds after the last soft key is pressed. Press X or Y soft key. The volume is distributed between the left and right sides of the vehicle. Press RES soft key briefly. The balance is reset to its center level. The radio switches back to the standard radio menu 8 seconds after the last button is pressed. 208