With the EMG BQC Control Active EQ Circuit for Bass Guitars, bassists have additional control over bass, midrange, and treble controls for either active or passive bass pickups. The system features a stacked mid range control for frequency sweeping and boost/cut functionality. The BQC has the added benefit of 4 onboard high frequency response curves as well as a 6dB per octave low frequency response boost/cut function, perfect for dialing in tone to the sweet spot!