Self-powered loudspeaker for sound masking

• US 10,074,353 B2
• Filed: 05/18/2017
• Issued: 09/11/2018
• Est. Priority Date: 05/20/2016
• Status: Active Grant

• Current Assignee: Cambridge Sound Management, Inc. (Biamp Systems, LLC)
• Original Assignee: Cambridge Sound Management, Inc. (Biamp Systems, LLC)
• Inventors: Cook, Gordon V., Nollman, Mitchell
• Primary Examiner(s): Sniezek, Andrew L
• Application Number:
  US15/598,528
• Publication Number:
  US 20170337916A1
• Time in Patent Office: 481 Days
• CPC Class Codes: G10K 11/1752 Masking
• CPC Class Codes: H04K 2203/12 for acoustic communication
• CPC Class Codes: H04K 2203/34 involving multiple cooperating jammers
• CPC Class Codes: H04K 3/42 characterized by the control of the jamming frequency or wavelength
• CPC Class Codes: H04K 3/43 characterized by the control of the jamming power, signal-to-noise ratio or geographic coverage area
• CPC Class Codes: H04K 3/825 by jamming
• CPC Class Codes: H04R 1/403 loud-speakers
• CPC Class Codes: H04R 2201/021 Transducers or their casings adapted for mounting in or to a wall or ceiling
• CPC Class Codes: H04R 2201/028 Structural combinations of loudspeakers with built-in power amplifiers, e.g. in the same acoustic enclosure H04R2499/10 takes precedence; Single (sub)woofer with two or more satellite loudspeakers for mid- and high-frequency band reproduction driven via the (sub)woofer H04R2205/026
• CPC Class Codes: H04R 2227/003 Digital PA systems using, e.g. LAN or internet
• CPC Class Codes: H04R 2227/005 Audio distribution systems for home, i.e. multi-room use
• CPC Class Codes: H04R 2420/09 Applications of special connectors, e.g. USB, XLR, in loudspeakers, microphones or headphones
• 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
• CPC Class Codes: H04R 3/12 for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04R 9/06 Loudspeakers

Abstract

A sound masking system includes a self-amplified loudspeaker emitter unit, with a driver and enlarged ported enclosure, sufficient to provide a frequency range down to a low frequency, such as about 125 Hz. To deliver the power, the power distribution architecture includes audio power amplifiers in the emitter housing of each loudspeaker. Raw power is delivered to each emitter unit through a cable and connectors, such as an Ethernet cable and connectors, in the same cable with the sound masking and audio signals. Inside the emitter units are electronics that efficiently convert the raw power and low level signal to drive the loudspeaker directly. The power comes from a typical desktop power supply, from which the power is combined with the sound masking and audio signals using a power injector unit that distributes the combined power and signals to loudspeakers. The loudspeakers can connect to an individually addressed sound masking network.

Claims

1. A direct field sound masking system for providing a direct path sound masking signal to the ears of a listener in a predetermined area of a building, said predetermined area including a ceiling and a floor, said system comprising:

a plurality of loudspeaker assemblies, each loudspeaker assembly coupled to one or more sources of an electrical sound signal,

wherein each of the plurality of loudspeaker assemblies has a voice coil coupled to an audio emitter operative to emit an acoustic sound signal corresponding to said electrical sound signal, wherein each said audio emitter is a cone emitter, wherein each of the plurality of loudspeaker assemblies has a low directivity index, and wherein each of the plurality of loudspeaker assemblies is constructed and oriented to provide the acoustic sound signal in a direct path to the ears of said listener in said predetermined area;

wherein the plurality of loudspeaker assemblies are interconnected via a plurality of multi-conductor wiring cables, each multi-conductor wiring cable of the plurality of multi-conductor wiring cables comprising at least one raw power conductor and at least one electrical sound signal conductor;

wherein at least one loudspeaker assembly of the plurality of loudspeaker assemblies is electrically coupled to a power injector via at least one multi-conductor wiring cable of the plurality of multi-conductor wiring cables, the power injector being electrically connected to (i) a control module comprising the one or more sources of the electrical sound signal, and (ii) a power supply, the power injector transferring power from the power supply onto the at least one raw power conductor of the at least one multi-conductor wiring cable, and the power injector transferring the electrical sound signal from the one or more sources of the electrical sound signal onto the at least one electrical sound signal conductor of the at least one multi-conductor wiring cable; and

an audio power amplifier within a loudspeaker enclosure of each loudspeaker assembly of the plurality of loudspeaker assemblies.

2. The direct field sound masking system of claim 1, wherein the electrical sound signal comprises at least one of a sound masking signal, a music signal and a paging signal.

3. The direct field sound masking system of claim 1, wherein said multi-conductor wiring cables comprise at least four pairs of conductors.

4. The direct field sound masking system of claim 3, wherein said multi-conductor wiring cables comprise four electrical sound signal conductors, two raw power conductors and two common ground conductors.

5. The direct field sound masking system of claim 1, wherein, in said plurality of loudspeaker assemblies each having a low directivity index, each said audio emitter has an effective aperture area that is less than or equal to the area of a circle having a diameter of 3.0 inches.

6. The direct field sound masking system of claim 1, wherein, in said plurality of loudspeaker assemblies each having a low directivity index, each said audio emitter has an effective aperture area that is less than or equal to the area of a circle having a diameter of 1.5 inches.

7. The direct field sound masking system of claim 1, wherein, in said plurality of loudspeaker assemblies each having a low directivity index, each said audio emitter has an effective aperture area that is equal to the area of a circle having a diameter of between 1.25 inches and 3 inches.

8. The direct field sound masking system of claim 1, wherein the loudspeaker enclosure of each loudspeaker assembly of the plurality of loudspeaker assemblies comprises a port opening from an exterior of an aperture of the loudspeaker assembly to an interior of the loudspeaker enclosure.

9. The direct field sound masking system of claim 8, wherein the port opening comprises a diameter of between about 0.3 inches and about 0.5 inches and a length of between about 1.5 inches and about 2.5 inches.

10. The direct field sound masking system of claim 1, wherein the loudspeaker enclosure of each loudspeaker assembly of the plurality of loudspeaker assemblies comprises an enclosure length of at least about 3.5 inches from an aperture face of the loudspeaker to the rear of the loudspeaker.

11. The direct field sound masking system of claim 1, wherein the loudspeaker enclosure of each loudspeaker assembly of the plurality of loudspeaker assemblies comprises an enclosure length of at least about 4.0 inches from an aperture face of the loudspeaker to the rear of the loudspeaker.

12. The direct field sound masking system of claim 1, wherein the acoustic sound signal comprises an acoustic sound masking signal comprising a corresponding sound masking spectrum, said sound masking spectrum having a low end frequency of at least about 80 Hz and a high end frequency of less than about 5300 Hz.

13. The direct field sound masking system of claim 12, wherein the sound masking spectrum comprises a frequency response of at least about 40 dB in the 125 Hz one-third octave band of the sound masking spectrum.

14. The direct field sound masking system of claim 13, wherein the sound masking spectrum comprises a frequency response of at least about 45 dB in the 125 Hz one-third octave band of the sound masking spectrum.

15. The direct field sound masking system of claim 1, wherein the sound masking spectrum comprises a frequency response that falls below about 20 dB in the range of between about 4000 Hz and about 5000 Hz of the sound masking spectrum.

16. The direct field sound masking system of claim 1, wherein the acoustic sound signal comprises a paging or music loudness of at least about 80 dBA in the covered area.

17. The direct field sound masking system of claim 1, further comprising a voltage regulator powering the audio power amplifier within the loudspeaker enclosure of each loudspeaker assembly of the plurality of loudspeaker assemblies.

18. The direct field sound masking system of claim 1, wherein each of the plurality of loudspeaker assemblies is constructed and oriented to provide the acoustic sound signal to at least one sound masking zone in the predetermined area of the building.

19. The direct field sound masking system of claim 1, further comprising a plurality of passive loudspeaker assemblies, each passive loudspeaker assembly coupled to the one or more sources of an electrical sound signal, wherein each of the plurality of passive loudspeaker assemblies lacks an audio power amplifier within a loudspeaker enclosure of each passive loudspeaker assembly of the plurality of passive loudspeaker assemblies.

20. The direct field sound masking system of claim 1, wherein at least one loudspeaker assembly of the plurality of loudspeaker assemblies further comprises an individually addressed network connector, the individually addressed network connector receiving audio signals individually addressed to the at least one loudspeaker assembly from an individually addressed sound masking network.

21. The direct field sound masking system of claim 20, wherein the individually addressed sound masking network comprises multi-conductor wiring cables that conduct both power and the individually addressed audio signals.

22. The direct field sound masking system of claim 21, wherein the multi-conductor wiring cables comprised in the individually addressed sound masking network comprise Power over Ethernet cables.

23. The direct field sound masking system of claim 20, wherein the individually addressed sound masking network comprises at least one of:

an individually addressed network processor, an individually addressed network loudspeaker controller and a network switch.

24. The direct field sound masking system of claim 23, wherein the individually addressed network processor comprises a processor configured to emit electronic signals comprising at least one of:

sound masking signals, paging signals and music signals.

25. The direct field sound masking system of claim 23, wherein the individually addressed sound masking network comprises an individually addressed network loudspeaker controller, and wherein at the least one loudspeaker assembly further comprises an internal loudspeaker connection directly from the individually addressed network loudspeaker controller to the voice coil of the at least one loudspeaker assembly.

26. The direct field sound masking system of claim 20, wherein the at least one loudspeaker assembly either (a) receives audio signals individually addressed to the at least one loudspeaker assembly from the individually addressed sound masking network, through the individually addressed network connector, or (b) is electrically coupled to a power injector via at least one multi-conductor wiring cable, the power injector being electrically connected to (i) a control module comprising the one or more sources of the electrical sound signal, and (ii) a power supply.