Abstract: An IP speaker system is disclosed that includes an IP speaker connected to one or more external analog speakers. The IP speaker comprises a CPU that provides an audio data stream for transmission to a first amplifier and a second amplifier. The first amplifier outputs a first analog audio signal at a first power level for driving an internal driver of the IP speaker, and the second amplifier outputs a second analog audio signal at a second power level for driving one or more external drivers of the one or more external analog speakers. The CPU supervises the one or more external analog speakers so as to detect any speaker failure, disconnection, short or other change in operational status. The IP speaker also comprises a power circuit that receives electrical power transmitted over a network cable as its input power and provides output power available for consumption by the IP speaker and the one or more external analog speakers.

Abstract: An apparatus for adding functionality to a private telephone system, comprising: a processing unit monitoring a telephone line and operable to perform said added functionality; a talk battery; and a switch having an input for a telephone, and an output selectable between an input of said private telephone system and said talk battery, said switch being controlled by said processing unit.