Mackie Big Knob Passive Passive 2x2 Studio Monitor ControllerMackie Big Knob Passive is a proven design that delivers professional level control, plus source and monitor selection for studios of any size. Its like having an audio traffic cop in your studio. Your best mix is always one that is achieved through disparate monitoring comparisons. Big Knob Passive makes that easier than ever. The passive audio path ensures sonic integrity is maintained throughout your signal chain. More than just a level control,