[en] A computer oriented numerical method is developed to calculate the various parameters associated with elastic wave propagation in the case of the most general crystalline system with 24 elastic constants. The method involves the evaluation of various wave surfaces (phase velocity, inverse velocity and energy surfaces), deviation of energy vector from wave vector, phonon magnification etc. starting from the basic Christoffel's equation in a general direction. Calculations have been carried out for various crystal systems such as cubic (A-15 compounds), tetragonal (ADP, KDP, TeO₂, BaTiO₃, Rutile, Indium), Orthorhombic (Iodic acid, Rochelle salt, Barium Sodium Niobate) and trigonal (Quartz, Sapphire) systems. This study of the phonon focusing is expected to find a very important role in various phenomena in crystals such as lattice conductivity, mode-mode coupling, etc. as these phenomena can be modulated by phonon focusing. (K.B.)