This article describes the Lissajous generalized figure and the original instrument for its investigation. Two specially prepared electrodynamic loudspeakers--a horizontal and a vertical--cause oscillations in two mirrors. It is possible to precisely control the motion of the mirrors, achieve a high frequency of oscillation and investigate anharmonic vibrations because loudspeakers are powered by electronic generators. Eccentric mounting, and rotation of a vertical loudspeaker, also allow composition of the oscillations in inclined directions, which generates Lissajous' generalized figures.