An audio amplifier having a variably configurable housing, which may be mounted to an interior surface of a motor vehicle. The housing is formed in two complementing housing sections mutually joined by a hinge, tether, or other connector. A power supply is contained in one housing section and an audio output module is contained in the other housing section. The power supply and audio output module may be connected by flexible signal conductors to accommodate pivot of the two housing sections relative to one another. A heat sink comprising cooling fins and communications and power terminals may be disposed on the exterior of the housing sections to enable conventional connection to an associated audio system. The hinge may incorporate a fixing element which releasably holds the two housing sections at a selected degree of pivot.