Our 3 band basses use a standard baxandall circuit centered appx. 500hz. Frequency slope is 6 db per octave. With bass control in max position, max output will occur at 40hz and drop at 6db per octave above 40hz. Maximum treble response drops at 6 db per octave at frequencies below appx.12 khz. Mid range is centered appx.500 hz. Control settings are interactive, therefore 6 db per octave slope only occurs when one control is in maximum position and the two remaining controls are set to minimum.