An acoustic apparatus may include a frame having an axially-opening annular open portion; a diaphragm supported by being attached to the annular open portion via a flexible edge member so as to be capable of vibrating in the axial direction; and a driving unit connected, at a connection portion at a center portion of the diaphragm, to the diaphragm to apply an axial-direction driving force to the diaphragm. The diaphragm includes first and second diaphragms that are mutually adjacent in the axial direction and joined together. When viewed in the axial direction, the second diaphragm has an outer diameter smaller than that of the first diaphragm. Each diaphragm includes a sheet member having an orientation dispersion structure including a shape-anisotropic filler dispersed in a resin with the long axis thereof oriented in a predetermined direction. The orientation directions of the sheet members of the first and second diaphragms mutually intersect.