Sound-producing unit

A sound-producing unit, comprising:

• a frame;
• a vibration system fixed to the frame, comprising a diaphragm, a voice coil configured to drive the diaphragm to vibrate and produce sound, and a flexible printed circuit board electrically connected to the voice coil;
• and
• a magnetic circuit system fixed to the frame, comprising a first fixing portion, a first elastic arm extending from the first fixing portion along a first direction, a second elastic arm extending from the first elastic arm along a second direction not parallel to the first direction, and a second fixing portion connected to the second elastic arm;
• wherein
• the first elastic arm comprises
• a first bending portion connected to one end of the first fixing portion and bent toward the other end of the first fixing portion, and a second bending portion extending from the first bending portion and bent toward the one end of the first fixing portion, the first bending portion being spaced apart from the first fixing portion and the second bending portion, and the first bending portion being connected to the first fixing portion and the second bending portion via arc-shaped transitions;
• the second elastic arm comprises
• a first arc portion connected to the second bending portion, a middle portion extending from the first arc portion along the second direction, and a second arc portion extending from the middle portion away from the first fixing portion and connected to the second fixing portion;
• the frame comprises
• a top wall, a bottom wall opposite to the top wall, and a side wall connecting the top wall and the bottom wall, the side wall forming an accommodation cavity;
• the voice coil is disposed in the accommodation cavity, the first fixing portion is fixed to the top wall, the diaphragm is fixed to the bottom wall, the second fixing portion is fixed to the diaphragm, and the first fixing portion and the second fixing portion are arranged in parallel;
• and
• the voice coil is fixed to the diaphragm and spaced apart from the second fixing portion, and a leading wire of the voice coil is connected to the second fixing portion.