Seismic wave scattering has received increased attention in strong-motion seismology in recent years as broadband simulations of ground motions for earthquake-engineering are becoming more important. Research in the 1980 and 1990 focused on estimating the scattering properties of the Earth from coda waves and other geophysical observations; these observational studies were partially supported with 2D wave-field simulations. Several theories for seismic back-scattering have been developed, based on the observational and numerical results. More recent work favors a model in which seismic forward scattering dominates. While we deploy an empirical back-scattering model in our hybrid broadband simulations, our current work focuses numerical 3D.