The DB14b is a special purpose direct box for applications where a stereo source signal can be separated, and individual volume controls used for each track. It provides a summed XLR output four uses such as an AV presentation from a laptop computer, or a rehearsing choir to a music track. Hum elimination is also included with the ground lift switch. It has stereo RCA and 1/8" inputs, 2 volume controls, RCA and XLR outputs, and uses no power.