A speaker comprising a diaphragm including a first layer defining a coil receiving opening therein, and a second layer attached to the first layer and traversing the coil receiving opening. The speaker further comprises a coil having an end extending into the coil receiving opening and abutting against a surface of the second layer that traverses the coil receiving opening. Thus, transmission efficiency between the coil and diaphragm is improved, which improves the audio quality of the speaker.