The Behringer XR4400 Multigate Pro Quad Expander/Gate combines 4 frequency-selective expanders/noise gates in a single rackspace. Suppresses noise during quiet passages and reduces crosstalk between mics. Features extremely short attack time for super-fast transients, parametric side chain filter for fine tuning, and flexible master/slave configurations. Includes servo-balanced XLR and 1/4" inputs/outputs.