An acoustic device that reproduces audio signals, the acoustic device including: a first acoustic reproducer that reproduces a signal corresponding to a treble range among the audio signals; a second acoustic reproducer that has a reproduction band from a cutoff frequency on a low frequency side to a cutoff frequency on a high frequency side, and reproduces a signal corresponding to a midrange lower than the treble range among the audio signals; and a harmonic overtone generator that generates a plurality of harmonic overtone signals for a fundamental tone signal corresponding to a specific frequency lower than the cutoff frequency on the low frequency side among the audio signals, wherein at least a part of the plurality of harmonic overtone signals is included in the reproduction band of the second acoustic reproducer.