  Finite volume schemes for hyperbolic conservation laws require a numerical
intercell flux. In one spatial dimension the numerical flux can be successfully
obtained by solving (exactly or approximately) Riemann problems that are
introduced at cell interfaces. This is more challenging in multiple spatial
dimensions. The active flux scheme is a finite volume scheme that considers
continuous reconstructions instead. The intercell flux is obtained using
additional degrees of freedom distributed along the cell boundary. For their
time evolution an exact evolution operator is employed, which naturally ensures
the correct direction of information propagation and provides stability. This
paper presents an implementation of active flux for the acoustic equations on
two-dimensional Cartesian grids and demonstrates its ability to simulate
discontinuous solutions with an explicit time stepping in a stable manner.
Additionally, it is shown that the active flux scheme for linear acoustics is
low Mach number compliant without the need for any fix.
