Phaser

– a Phaser basically Creates Several Notch Filters 

– the LFO Moves “Notch Filters” Across the Spectrum, thus Removing Frequencies from the Audio which Causes the Typical Phase Sound

– with High Speeds the Phase may even Change the Pitch Sightly (causing an Effect similar to Vibrato)

– Phasers are Naturally Filters and Gain Nothing from Multiband Processing, unless the Settings for Each Band are Different