A composite speaker is provided capable of obtaining larger sound output than that of a conventional flat panel speaker and flat speaker when input with an audio signal of the same strength. The composite speaker includes: one magnet or a plurality of magnets disposed at predetermined intervals to each other; a yoke for forming a magnetic circuit with a magnetic gap to the magnets; a voice coil disposed in a gap between the magnets and the yoke so as to interlink with the magnetic circuit; a diaphragm with the voice coil fixed to one face thereof; a frame that supports the diaphragm at peripheral edge portions of the diaphragm and houses the magnets and the yoke; a speaker base plate fixed to the frame at the side of the frame supporting the diaphragm or at the side of the frame opposite to the side supporting the diaphragm; and a phase rotation member configured by an elastic member provided between the speaker base plate and the yoke; wherein sound is generated from both the diaphragm and the speaker base plate.