The present invention allows for the further enhancement of a low pitch range with a simple structure without increasing the size.The present invention is provided with: a pipe (102) open one end side and the other end side; a speaker unit (104) that is coaxial with the pipe (102), arranged at the one end side of the pipe (102), and driven on the basis of an audio signal; and an edge-cum-diaphragm (102B) that is coaxial with the pipe (102), installed at the other end side of the pipe (102), and vibrates in response to a sound wave that passes through the pipe (102). While the pipe (102) functions as a resonance tube by being excited to vibration with the sound wave that is radiated from the speaker unit (104) and passes through the pipe (102), the edge-cum-diaphragm (102B) functions as a passive radiator by vibrating in response to the sound wave that passes through the pipe (102).