Mini-horns provide a loud and penetrating notification sound controlled by SmartSync two-wire operation. The compact package allows mounting in a variety of convenient locations. An output level switch allows selection of low or high sound output as required for the location. SmartSync operation mode uses a two-wire circuit to activate the horn and strobe on the same Notification Appliance Circuit (NAC) and then the horn can be silenced while the strobe remains flashing. The horn operates as On until silenced while the strobe operation is On until reset.