An improved filtering system for loudspeaker equalization is comprised of two filtering sections, a single pole filtering section having single pole filters for shaping the frequency response of the audio signal over the operative bandwidth of the equalized loudspeaker system, and a parametric filtering section that provides for localized parametric equalization for compensating for room or other environmental resonances. The filtering system of the invention can be used to create a wide variety of useful filter shapes, while minimizing phase distortion that can harm the transient response of phase-aligned loudspeakers of a loudspeaker system.