A networked speaker device includes a sealed housing and an Ethernet port in the housing for receiving power and audio data from a network router via an Ethernet cable. A power supply subsystem in the housing manages the power received at the Ethernet port. A microprocessor subsystem, powered by the power supply subsystem, receives and processes the audio data to generate output audio signals. A digital audio amplifier, powered by the power supply subsystem, amplifies the output audio signals to drive a speaker driver to render an audio output. The device also includes at least one heater resistor in the housing powered by the power supply subsystem. The at least one heater resistor is controlled by the microprocessor subsystem to automatically heat the interior of the housing when temperature inside the housing falls below a given temperature.