Linear-Phase Bandsplitting: Theory and Applications

There are a number of applications for banks of band-pass filters in professional audio studios for both film and music production. Digital techniques for bandsplitting are explored which have the property that the spectrum may be separated into a number of bands such that when these bands are added back together, the result is a pure delay. There need be no amplitude or phase distortions other than delay. This allows such applications as linear-phase graphic equalizers, multiband noise gates, and many other improvements over conventional studio equipment. These algorithms have been implemented on a large-scale audio signal processor and run in real time. They are currently being used in major motion picture production.