The Series 80B 500 Series EQ incorporates a classic four band equaliser which is identical to that employed in the Trident Series 80 console. It consists of frequency switchable high and low pass shelving sections, coupled with two swept low and high mid range bands and a switchable 50Hz, 12dB per octave filter. Both swept midranges have been carefully chosen for maximum effect on music programme and a good degree of overlap is provided