Sound producing device

Disclosed is a sound producing device, including a magnetic circuit system and a vibration system. The magnetic circuit system includes a primary magnet steel and a secondary magnet steel with a magnetic gap therebetween, wherein the secondary magnet steel includes a body portion and a protruding portion protruding in a direction toward the primary magnet steel from the body portion, and wherein the primary magnet steel has a primary magnetic conductive plate disposed thereon. The vibration system includes a diaphragm and an voice coil wound by wire, wherein the voice coil is inserted in the magnetic gap to drive the diaphragm to vibrate, and wherein a number of layers of wire winding at an end of the voice coil away from the diaphragm are less than that of layers of wire winding at another end of the voice coil contacting with the diaphragm, to form a notch.