The PSM15P provides 400 Watts Peak in a Bi-amped configuration to the internal components. Also, their internal electronic crossover insures maximum efficiency and clarity. The preamp section of these workhorses includes Power Switch and Indicator on the back panel (as well as a blue LED indicator on the front of the unit), Mic/Line Button for Input matching, Gain Control for unity gain setting, 3 band EQ, and Master Level Control. These preamps are so versatile that you can plug in nearly any type of device from a low output microphone to a line level keyboard and achieve perfect musical output. For connecting your devices to the PSMP enclosures we have provided a combo XLR / 1/4" input jack and an XLR through to connect to another powered speaker or board. Both the XLR and 1/4" inputs and output are balanced and include a ground lift switch for the elimination of unwanted noise. The detachable line cord and voltage selector make these enclosures usable in a variety of different locations around the world.