Abstract <p>The propagation of acoustic waves in a plate made of a material with piezoelectric, piezomagnetic, and magnetoelectric effects is theoretically investigated. It is assumed that the material belongs to triclinic syngony, i.e., no simplifications due to crystallographic symmetry are used. Expressions for the impedance of such a plate are obtained, and its properties are established. Using the impedance properties, the general patterns of the acoustic spectrum of the plate are analyzed. Expressions for the bending wave velocity in a thin homogeneous and bilayer plate, as well as in a three-layer plate with the same outer layers, are derived.</p>