  We discuss the mechanism through which classicalization may occur during the
collapse of a spherical field configuration modelled as a wavepacket. We
demonstrate that the phenomenon is associated with the dynamical change of the
equation of motion from a second-order partial differential equation of
hyperbolic to one of elliptic type. Within this approach, we rederive the known
expression for the classicalization radius. We also find indications that
classicalization is associated with the absence of wave propagation at
distances below the classicalization radius and the generation of shock fronts.
The full quantitative picture can be obtained only through the numerical
integration of a partial differential equation of mixed type.
