phaseequalizer

A phaseequalizer is a device or digital algorithm designed to modify the phase response of a signal over frequency while preserving, or nearly preserving, its amplitude response. Unlike conventional equalizers that shape loudness or tone by changing magnitude, a phase equalizer focuses on the alignment and timing of spectral components, which can affect perceived coherence and stereo image without altering loudness.

Phase equalizers are commonly realized with all-pass networks in analog domain, or phase-centric filters in digital processing. An all-pass section changes phase with little or no change to magnitude. By cascading multiple sections with carefully chosen pole–zero placements, engineers can craft a target phase curve across the spectrum.

Applications include aligning the phase of multiple drivers in loudspeaker crossovers, compensating phase distortion in cables or optical fibers, and shaping stereo imaging or impulse response in recording, mastering, and film post‑production. In communications and video, phase equalization can compensate dispersion and timing skew introduced by channels.

Design and implementation considerations include stability, numerical precision in digital realizations, and the trade‑off between phase linearity and transient performance. Phase changes correspond to time-domain reshaping of the impulse response, which can affect transients and perception even when the magnitude is flat.

Related concepts include all-pass filters, phase shift networks, and group delay; phase equalization is often used in combination with magnitude equalization to achieve a desired overall response.