Provided is a speaker, including a frame; a vibration unit fixed to the frame; and a magnetic circuit unit driving the vibration unit to vibrate and produce sound and provided with a magnetic gap. The vibration unit includes a diaphragm, a voice coil, and an elastic support assembly; the diaphragm includes a diaphragm body, a diaphragm fixing portion, a diaphragm supporting portion, and a reinforcing portion; the diaphragm fixing portion has a rectangular structure with round corners, and the diaphragm supporting portion is located at the round corners; the frame is provided with an assembly hole; the vibration unit further includes a fixing ring; and the elastic support assembly includes an elastic member and an auxiliary diaphragm. With this structure, the overall strength and reliability of the speaker are improved.