Rolls RPQ160B Parametric EqualizerThe RPQ160b is a 4 band parametric equalizer with high and low shelving filters and is capable of processing frequencies from 20Cy to 20KCy. These sort of units are for reducing room resonances, anti feedback, special effects, room flattening, etc.. The 160 also features 3 different jack types as well as balanced and unbalances ins and outs. Features: 4 Bands of parametric equalization RCA, 1 4" and XLR inputs and outputs Adjustable high and low