DBX ZonePRO 640M 6-Input 4-Output Digital Zone ProcessorThe 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 six inputs and four 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.