Digital power link audio distribution system and components thereof

• US 20070223722A1
• Filed: 03/13/2006
• Published: 09/27/2007
• Est. Priority Date: 03/13/2006
• Status: Active Grant

• Current Assignee: D&M Holdings Incorporated (DEI Holdings Incorporated)
• Original Assignee: Altec Lansing Technologies (Infinity Group Holding Co. LLC)
• Inventors: Merrey, F., Jones, Gary
• Granted Patent: US 8,385,561 B2
• Time in Patent Office: Days
• US Class Current: 381/77
• CPC Class Codes: H04B 2203/547 via DC power distribution
• CPC Class Codes: H04B 3/58 Repeater circuits
• 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 audio distribution system in one embodiment includes a master device, a powered speaker unit, and an expander device. The master device has an output port for receiving a cable carrying an electrical power signal along with a digital audio signal. The speaker unit includes a first port for receiving the electrical power signal and the digital audio power signal, and a second port for sending the signals. A digital-to-analog converter in the speaker unit converts the digital audio signal to an analog audio signal, and a speaker driver uses the signal to produce sound. The expander device is electrically connectable to the second port of the speaker unit for providing electrical power to one or more further speaker units. In another embodiment, the invention provides a master mixer device and a speaker unit. The master mixer device includes a digital signal processor for receiving and separately processing a speech channel having digital audio containing speech content and a music channel having digital audio containing music content. In an embodiment a powered speaker unit employing a class D amplifier for reproducing sound is further disclosed. A digital power link in port is provided in the powered speaker for receiving a cable carrying a digital audio signal and electrical power.

Claims

1. An audio distribution system, comprising:

a master device, comprising;

an output port for receiving a cable;

an electrical power conductor electrically connected to the port for causing an electrical power signal from a power supply to be conducted over the cable; and

,

a digital audio signal conductor electrically connected to the output port for causing a digital audio signal to be conducted over the cable;

a speaker unit, comprising;

a first port and a second port, at least one port being adapted to receive the electrical power signal and the digital audio power signal, and at least the other port being adapted to send the electrical power signal and the digital audio signal.

a digital-to-analog converter for converting the digital audio signal to an analog audio signal; and

,

at least one speaker driver for producing sound based upon the analog audio signal;

an expander device electrically connectable to the port of the speaker unit that is adapted to send, for providing electrical power to one or more further speaker units.

2. The system in accordance with claim 1, further comprising a digital power amplifier which uses pulse-width-modulated digital signals to switch an output power amplification device, thereby generating the analog audio signal.

3. The system in accordance with claim 1, wherein the first and second ports of the speaker unit can each be used as an input for receiving the electrical power signal and the digital audio power signal, or an output for sending the electrical power signal and the digital audio power signal.

4. The system in accordance with claim 1, wherein each port is configured to receive a cable having multiple twisted pairs of conductors.

5. The system in accordance with claim 4, wherein each port is wired such that the electrical power signal is conducted by at least a first twisted pair of the conductors and the digital audio signal is conducted by at least one other twisted pair of the conductors.

6. The system in accordance with claim 5, wherein the electrical power signal is conducted by a plurality of twisted pairs of conductors.

7. The system in accordance with claim 6, wherein at least one of the plurality of twisted pairs of conductors conducts electrical power at a voltages different than the voltage of at least one other of the plurality of twisted pairs of conductors.

8. The system in accordance with claim 1, wherein the master device further comprises an analog-to-digital converter for converting analog audio signals received from an external analog audio source to digital form, and wherein the digital audio signal conducted by the digital audio signal conductor comprises a signal output by the analog-to-digital converter.

9. The system in accordance with claim 1, wherein the master device further comprises a mixer for mixing audio signals from a plurality of audio sources.

10. The system in accordance with claim 1, wherein the digital audio signal conducted by the digital audio signal conductor is from a digital audio source which is external to the master device.

11. The system in accordance with claim 10, wherein the external audio source comprises a microphone.

12. The system in accordance with claim 1, wherein the digital audio signal conducted by the digital audio signal conductor is from a digital audio source which is internal to the master device.

13. The system in accordance with claim 1, wherein the audio source comprises an analog audio source.

14. The system in accordance with claim 1, wherein the audio source is separate from the master device.

15. The system in accordance with claim 1, wherein the audio source is integrated into the master device.

16. The system in accordance with claim 1, wherein the at least one speaker driver comprises first and second speaker drivers, the first speaker driver being adapted to reproduce sound in a first frequency range and the second speaker driver being adapted to reproduce sound in a second frequency range.

17. The system in accordance with claim 16, wherein the first speaker driver is a woofer and the second speaker driver is a tweeter.

18. An audio distribution system, comprising:

a master mixer device, comprising;

a digital signal processor for receiving and separately processing a speech channel having digital audio containing speech content and a music channel having digital audio containing music content;

an output port for receiving a cable;

an electrical power conductor electrically connected to the port for causing an electrical power signal from a power supply to be conducted to the cable; and

,

a digital audio signal conductor electrically connected to the output port for causing a digital audio signal to be conducted over the cable;

a speaker unit, comprising;

an input port for receiving the electrical power signal and the digital audio power signal.

19. A powered speaker unit employing a class D amplifier for reproducing sound, comprising:

a digital power link in port for receiving a cable carrying a digital audio signal and electrical power;

a digital power amplifier which uses pulse-width-modulated digital signals to switch an output power amplifier device, thereby generating an analog audio signal; and

,

at least one speaker driver for reproducing sound based upon the analog audio signal.

20. The powered speaker unit in accordance with claim 19, further comprising a digital power link out port for sending digital audio and power over a second cable.

21. The powered speaker unit in accordance with claim 19, further comprising a pulse-width-modulation controller for converting digital audio signals to pulse-width-modulated digital signals.

22. The powered speaker unit in accordance with claim 21, wherein the pulse-width-modulation controller comprises a controller for converting pulse-code-modulated digital audio signals to pulse-width-modulated digital audio signals.

23. A powered speaker unit employing a class D amplifier for reproducing sound, comprising:

a link in port for receiving a cable carrying a first digital audio signal;

a link out port for conducting a second digital audio signal;

a digital power amplifier which uses pulse-width-modulated digital signals to switch an output power amplifier, thereby generating at least one analog audio signal; and

,

at least one speaker driver for receiving the analog audio signal and reproducing sound in accordance therewith.

24. The powered speaker unit in accordance with claim 23, wherein the first digital audio signal and the second digital audio signal are the same signal.

25. The powered speaker unit in accordance with claim 23, wherein the at least one speaker driver comprises first and second speaker drivers, the first speaker driver being adapted to reproduce sound in a first frequency range and the second speaker driver being adapted to reproduce sound in a second frequency range.

26. The powered speaker unit in accordance with claim 25, wherein the first speaker driver is a woofer and the second speaker driver is a tweeter.

27. The powered speaker unit in accordance with claim 23, wherein the digital power amplifier includes a high frequency amplification channel and a low frequency amplification channel.

28. The powered speaker unit in accordance with claim 23, wherein the at least one analog audio signal comprises a high-frequency analog audio signal and a low-frequency analog audio signal.

29. The powered speaker unit in accordance with claim 28, wherein the at least one speaker driver comprises a first speaker driver configured to receive the high-frequency analog audio signal and second speaker driver configured to receive the low-frequency analog audio signal.

30. The powered speaker unit in accordance with claim 29, wherein the first speaker driver configured to receive the high-frequency analog audio signal comprises a tweeter and the second speaker driver configured to receive the low-frequency analog audio signal comprises a woofer.

31. The powered speaker unit in accordance with claim 23, further comprising a pulse-width-modulation controller for converting digital audio signals to pulse-width-modulation digital signals.

32. The powered speaker unit in accordance with claim 31, wherein the pulse-width-modulation controller comprises a controller for converting pulse-code-modulated digital audio signals to pulse-width-modulated digital audio signals.

33. The powered speaker unit in accordance with claim 23, further comprising a digital signal processor for receiving and processing digital audio and for providing at least one processed digital audio signal to the digital power amplifier.