The Crown XFMR-4 is a rackmountable transformer to provide impedance matching between amplifier outputs and constant high voltage lines delivering the audio to suitable speakers. This unit allows amplifiers without direct 70Vrms or 100Vrms output capability to drive distributed speaker systems designed to operate at those voltages for up to 4x channels. Leads are provided to easily incorporate the XFMR unit with ComTech DriveCore types of amplifiers.