A playback system for playback of audio content by a set of speakers in a playback enviroment, comprising: - a decoder configured to receive and decode an encoded signal indicative of an object based audio program, the audio program being indicative of the audio content and including multiple speaker channels, user-selectable object channels, and object related metadata corresponding to each object channel, each object channel being indicative of an audio object, wherein the object related metadata of each object channel is indicative of a position within the playback environment from which the object channel is to be rendered; - a controller for enabling user-selection of object channels included in the audio program, wherein the decoder is configured to decode object channels selected by the user in response to the object based audio program and in response to control data from the controller indicative of the selected object channels; - an object processing subsystem configured to output the user-selected object channels of the user-selectable object channels included in the audio program and the corresponding object related metadata, and pass-through the multiple speaker channels from the decoder; - a rendering subsystem configured to map the user-selected object channels output from the object processing subsystem to the set of speakers, using the corresponding object related metadata, and mix the user-selected object channels with the multiple speaker channels, for rendering the audio content output from the subsystem for playback by the set of speakers in the playback enviroment. - a decoder configured to receive and decode an encoded signal indicative of an object based audio program, the audio program being indicative of the audio content and including multiple speaker channels, user-selectable object channels, and object related metadata corresponding to each object channel, each object channel being indicative of an audio object, wherein the object related metadata of each object channel is indicative of a position within the playback environment from which the object channel is to be rendered; - a controller for enabling user-selection of object channels included in the audio program, wherein the decoder is configured to decode object channels selected by the user in response to the object based audio program and in response to control data from the controller indicative of the selected object channels; - an object processing subsystem configured to output the user-selected object channels of the user-selectable object channels included in the audio program and the corresponding object related metadata, and pass-through the multiple speaker channels from the decoder; output the user-selected object channels of the user-selectable object channels included in the audio program and the corresponding object related metadata, and pass-through the multiple speaker channels from the decoder; - a rendering subsystem configured to map the user-selected object channels output from the object processing subsystem to the set of speakers, using the corresponding object related metadata, and mix the user-selected object channels with the multiple speaker channels, for rendering the audio content output from the subsystem for playback by the set of speakers in the playback enviroment. map the user-selected object channels output from the object processing subsystem to the set of speakers, using the corresponding object related metadata, and mix the user-selected object channels with the multiple speaker channels, for rendering the audio content output from the subsystem for playback by the set of speakers in the playback enviroment.