The ZonePRO 640m offers fixed I/O, pre-configured architecture, configurable insert processing and optional duplication of audio channels to another ZonePRO device via a link bus. The 640m features a total of 6 inputs and 4 outputs. Inputs include four balanced mic/line switchable terminal block inputs and two mono-summed pairs of unbalanced RCA inputs. Hardware-controlled microphone gain allows adjustment of microphone gain per channel. The 640m device has a pre-configured architecture with input processing, a central matrix and output processing. Two input insert positions and one output insert position allow channel-specific insert processing to be configured. AutoWarmth, a psychoacoustic function that maintains full frequency bandwidth even when the signal level has dropped, is permanently available on each output zone. A link bus allows duplication of the first six audio channels to another ZonePRO device in applications where additional output zones are required. The front panel of the 640m features comprehensive signal metering, an informative LCD display and user-specified front panel control. Additional system control is offered in the form of optional Zone Controllers. This collection of hardware wall-controllers represents a series of simple, elegant user interfaces for functions such as volume, source and preset control. All ZonePRO devices can be controlled by third party control systems via RS-232 or Ethernet as applicable (see table for further information). ZonePRO designer - the configuration, control and monitoring software for the ZonePRO family of devices offers control of the ZonePRO 640m via Ethernet or RS-232. The configuration wizard within ZonePRO designer guides users through the step-by-step configuration process of the 640m.