XFMR4 4ch Rack-Mountable Constant Voltage Transformer 1UThe Crown XFMR 4 and XFMR 8 are rack mountable transformers to provide impedance matching between amplifier outputs and constant voltage loudspeakers. This unit allows amplifiers without direct 70Vrms or 100Vrms output capability to drive distributed speaker systems designed to operate at those voltages. Product Features Transformers provide four channels of impedance matching for constant voltage operation Provides 70Vrms and 100Vrms output when used