The ZonePRO 641m 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 641m 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 641m 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 641m features a power status LED, a network traffic LED, and an RS-232 control port. 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 641m via Ethernet or RS-232. The configuration wizard within ZonePRO designer guides users through the step-by-step configuration process of the 641m.