A vehicle sound system includes a subwoofer system having a subwoofer, a satellite amplifier for driving the subwoofer, a host amplifier for receiving an audio signal, a noise management processing unit for providing, to the host amplifier, information to be used for achieving a desired audio environment, a sensor for providing information to the noise management processing unit concerning the ambient audio environment, a control line between the satellite amplifier and the host amplifier for transmission of control signals to the satellite amplifier, and a signal line between the satellite amplifier and the host amplifier for transmission of audio signals to the satellite amplifier, the satellite controller being configured to cause a diagnostic signal to be placed on the control line, the diagnostic signal being indicative of an operating condition of the subwoofer system.