A speaker includes: a frame, a vibration system, including a diaphragm and a voice coil assembly, and a magnetic circuit system, comprising a lower plate, a first main magnet and a first auxiliary magnet, a main pole plate, and an upper plate, wherein the upper plate includes a body portion and a groove recessed from the body portion to the lower plate, the groove includes a base, and a connecting arm connected with the body portion and the base, the base is closer to the body portion than the lower plate, the speaker further includes a second auxiliary magnet located in the groove, the base is clamped between the first auxiliary magnet and the second auxiliary magnet.