  Solution of Helmholtz equation with impedance boundary condition on finite
interval is equivalently reformulated as steady state of initial boundary value
problem for first order hyperbolic system of partial differential equations.
Particularly interesting property of the proposed hyperbolic model is that
steady state is achieved in finite time. For large wavenumber the numerically
challenging task for Helmholtz equation is achieving high accuracy with small
number of nodal points. We successfully solved this problem by means of using
well balanced scheme approach. Numerical tests demonstrate excellent
computational potential of the proposed method: high accuracy is achieved for
large wavenumber with small number of nodal points in space and time.
