Intelligent speaker unit for speaker system network

• US 5,406,634 A
• Filed: 03/16/1993
• Issued: 04/11/1995
• Est. Priority Date: 03/16/1993
• Status: Expired due to Term

• Current Assignee: Cirrus Logic Incorporated
• Original Assignee: Flackface, Inc. (Cirrus Logic Incorporated)
• Inventors: Zwiebel, Richard C., Melanson, John L., Anderson, Charles W.
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): ISEN, FORESTER W
• Application Number:
  US08/033,697
• Time in Patent Office: 756 Days
• Field of Search: 381/80, 381/81, 381/82, 381/2, 381/109
• US Class Current: 381/82
• CPC Class Codes: H04R 2227/003 Digital PA systems using, e.g. LAN or internet
• CPC Class Codes: H04R 27/00 Public address systems circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; monitoring or testing arrangements for public address systems H04R29/007; amplifiers H03F

Abstract

An intelligent speaker unit is controlled by control data transmitted with the digital audio data. The intelligent speaker has a Digital Signal Processor (DSP) for processing the audio data in accordance with the control data. The control data contains an address to select the speaker unit. The DSP for the speaker unit processes audio data digitally based on parameters in the control data. The processed digital audio data is then converted to an analog signal which is amplified and applied to the speaker. The digital audio data is time division multiplexed on a TDM bus. Each time slot on the TDM bus contains audio data for one digital audio channel. The control data is placed on the TDM bus as one channel (time slot) or is distributed as control bits through all the other channels. The control data also contains channel select data. Accordingly the DSP in a selected speaker unit may in turn select its audio data from a plurality of audio channels based on the control data the DSP receives. Further, the DSP may mix the selected audio channels by accumulating the audio data from the selected channels. Further, the control data contains audio control data for volume, speaker equalization and sound delay.

Claims

1. In a public address system having a transmission control center for transmitting digital audio data from multiple audio sources, intelligent speaker apparatus remote from the transmission control center for reproducing mixed audio signal sound from digital audio data from a plurality of the audio sources, the audio data from each audio source being transmitted as a distinct digital audio channel by the control center to said apparatus, said apparatus being controlled by control data transmitted by the control center, said apparatus comprising:

processing means for processing the audio data to produce an audio signal;

speaker means responsive to the audio signal for reproducing sound;

said audio data includes audio data from more than one digital audio channel;

said control data including audio control data and channel select data;

channel select means responsive to the channel select data for selecting a plurality of the audio channels to provide audio data for processing by said processing means; and

said audio control data includes audio control data for audio data in each selected channel; and

processing means responsive to the audio control data for controlling the audio characteristics of the audio data in each selected channel to produce controlled audio data for each selected channel;

said processing means responsive to said channel select means for accumulating controlled audio data from the selected channels and thereby mixing controlled audio signals from a plurality of selected channels to generate the mixed audio signal;

said speaker means responsive to the mixed audio signal for reproducing sound from selected channels and the sound from each channel being controlled by the audio control data for the channel.

2. The apparatus of claim 1 and in addition:

said control data includes audio control data for each speaker means; and

means responsive to the audio control data for controlling the audio characteristics of the accumulated audio data.

3. The apparatus of claim 1 wherein:

said control data includes an address unique to the intelligent speaker apparatus; and

enabling means responsive to said address for enabling said processing means.

4. The apparatus of claim 3 wherein said control data includes control parameters for the processing performed by said processing means and said processing means comprises:

digital signal processing means for processing digital audio data in accordance with the control parameters; and

conversion means for converting the processed digital audio data from said processing means into an analog signal for said speaker means.

5. The apparatus of claim 4 and in addition:

said control parameters include audio control data for controlling one or more audio characteristics including volume, equalization and sound delay for said speaker means; and

said digital signal processing means responsive to the audio control data for controlling one or more of the volume, equalization and sound delay in the processed audio data prior to conversion of said data by said conversion means.

6. 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.

7. The method of claim 6 and in addition:

resetting said processing step to an inoperative state whereby no sound is produce by the intelligent speaker unit until channel select data and audio control data are set in the unit by said setting step.

8. The method of claim 6 wherein:

said speaker select data comprises an address for the intelligent speaker unit;

said channel select data comprises mix control parameters including channel select parameters and gain control parameters;

said selecting step selecting the channels based on the channel select parameters;

processing audio data from the selected audio channels in accordance with the gain control parameters for each selected channel; and

said accumulating step accumulates the gain processed audio data from the selected channels to produce mixed audio data.

9. The method of claim 8 wherein:

said audio control data comprises audio control parameters for controlling one or more audio characteristics including volume, equalization and sound delay for the speaker unit; and

said processing step processes the accumulated audio data in accordance with audio control parameters to control one or more of the volume, equalization and sound delay in the accumulated audio data.

10. 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.

11. The apparatus of claim 10 wherein:

said audio control information includes volume control, speaker equalization control and sound delay control parameters; and

said audio processing means responsive to the control parameters for controlling volume, equalization and sound delay in the reproduction of mixed sound from the selected channels at each audio device.