A modular communication system that includes a battery operated portable multimedia player is used to remotely control a accessory unit arranged to provide an output audio stream to an audio output device. At a user's discretion, the multimedia player can also be used to provide the original audio source material that is, in turn, processed by the accessory unit for output to the audio output device or an accessory unit can be used to provide the audio source material from, for example, a radio tuner incorporated therein.