A speaker includes a frame having an accommodation space; a magnetic circuit system accommodated in the accommodation space; and a vibration system accommodated in the accommodation space for generating sound. The vibration system includes a diaphragm and a voice coil. The diaphragm includes a first part fixed with the frame and a second part arranged between the first part and the frame. One end of the second part is connected with the first part. The accommodation space is divided by the second part into a first accommodation space for accommodating the magnetic circuit system and a second accommodation space for accommodating the voice coil.