Tabletop Studio Monitor Management Device w/Talkback, Headphone Send & Monitor Switching. Now, more than ever, professional, project and home studios need a Big Knob. You know, a simple monitor switching and level control box with built-in talkback functions that sits on your desktop. With the Big Knob's multitude of rear-panel connections, this Mackie marvel lets you easily switch between three sets of studio monitors, four different stereo sources, and even send musicians their own custom headphone mixes while communicating with them via the built-in Talkback microphone. And with its high-end sound quality and robust construction, Big Knob is right at home in professional studios.