Intelligent speaker unit for speaker system network

In a public address system having a transmission control center and a plurality of remote intelligent speaker units where said control center transmits digital audio data from a plurality of audio sources over a plurality of channels and also transmits audio control data, a method for selectively reproducing sound at each intelligent speaker unit from digital audio data in a plurality of the channels, said method controlling the sound reproduced at the speaker unit in accordance with control data transmitted with the digital audio data, said control data includes speaker select data, channel select data and audio control data, said method comprising the steps of:

• setting channel select data and audio control data in said speaker unit if said unit is selected by the speaker select data;
• selecting a plurality of the audio channels for mixing at the selected speaker unit in accordance with the channel select data;
• said channel select data includes channel audio control data for each selected channel;
• processing the audio data in each selected channel in accordance with the channel audio control data for the channel to produce channel-controlled audio data;
• accumulating the channel-controlled audio data from the selected audio data channels to produce accumulated channel-controlled audio data;
• processing the accumulated channel-controlled audio data from selected channels to produce a channel-controlled mixed audio signal;
• and
• reproducing sound from the channel-controlled mixed audio signal.

Sound distribution apparatus in a public address system for controlling the distribution of audio information contained in two or more selected channels to selected audio devices and independently controlling the sound produced from each selected channel at each selected audio device, said apparatus comprising:

• a plurality of audio information sources;
• a speaker subsystem at each audio device having means for reproducing sound from received audio information, a mixing means, an audio processing means and an enabling means;
• control center means for transmitting the audio information from each of a plurality of the audio sources to said speaker subsystems and for transmitting audio control information, mixing control information and address information to said speaker subsystems;
• said enabling means responsive to the address information for enabling a speaker subsystem identified by the address information;
• said mixing means responsive to said mixing control information for selecting two or more channels of audio information, the selected channels being identified by said mixing control information, and said mixing means for controlling the gain of each of the selected channels in accordance with said mixing control information to produce mixed audio information;
• and
• said audio processing means responsive to said audio control information for controlling the audio characteristics of mixed sound from the mixed audio information in accordance with control parameters in the audio control information.