... balance 3."3" or"6 MIC,master controller 4.chairman conference sound system(ETF-6300G)Function:1.it was adopted two frequency ... bass output.2.There is a remote telephone INPUT makes sound reduce well, High definition, the noise is efficiently small, ... ,it apply to multimedia room,functional hall,technique room and conference room. PARAMETER:Working voltageAC220V±10%/50HzOutput impedanceREC:200Ω/ LINE: ...