An exemplary vibration unit of a speaker includes a diaphragm and a coil connected to the diaphragm. The coil includes a main body, and a lead-out wire extending from a periphery of the main body. The lead-out wire includes a first segment extending from the periphery of the main body and being tangential to the main body, and a second segment extending from the first segment. The first and second segments are adhered to the diaphragm.