EP1355510A2 - Loudspeaker arrangement and switching apparatus therefor - Google Patents

Loudspeaker arrangement and switching apparatus therefor Download PDF

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Publication number
EP1355510A2
EP1355510A2 EP03290832A EP03290832A EP1355510A2 EP 1355510 A2 EP1355510 A2 EP 1355510A2 EP 03290832 A EP03290832 A EP 03290832A EP 03290832 A EP03290832 A EP 03290832A EP 1355510 A2 EP1355510 A2 EP 1355510A2
Authority
EP
European Patent Office
Prior art keywords
loudspeakers
amplifiers
loudspeaker
power
power output
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP03290832A
Other languages
German (de)
French (fr)
Other versions
EP1355510A3 (en
Inventor
Alan Anderson Hoover
Mark Alan Simpson
Robert Edward Morris
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thomson Licensing SAS
Original Assignee
Thomson Licensing SAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US10/126,746 external-priority patent/US20030197811A1/en
Priority claimed from US10/126,743 external-priority patent/US20030198358A1/en
Application filed by Thomson Licensing SAS filed Critical Thomson Licensing SAS
Publication of EP1355510A2 publication Critical patent/EP1355510A2/en
Publication of EP1355510A3 publication Critical patent/EP1355510A3/en
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R5/00—Stereophonic arrangements
    • H04R5/04—Circuit arrangements, e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers
    • H04R3/12—Circuits for transducers for distributing signals to two or more loudspeakers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R2420/00—Details of connection covered by H04R, not provided for in its groups
    • H04R2420/01—Input selection or mixing for amplifiers or loudspeakers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R2420/00—Details of connection covered by H04R, not provided for in its groups
    • H04R2420/03—Connection circuits to selectively connect loudspeakers or headphones to amplifiers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers
    • H04R3/007—Protection circuits for transducers

Definitions

  • the present invention relates generally to acoustic sound reproducing apparatus, and more particularly, to a loudspeaker arrangement and switching apparatus therefor.
  • a television receiver with its loudspeakers, and an audio sound system with its loudspeakers, are often disposed in a common listening room with the two not generally operated at the same time because the user cannot simultaneously listen to both when each has its own program source.
  • the utilization efficiency of each of the various loudspeakers is reduced.
  • the audio signal is a stereophonic signal reproduced in a multidirectional surround sound system such as a Dolbyä 5.1 sound system
  • five loudspeakers are used with one of the loudspeakers being a center loudspeaker which receives an L+R signal.
  • the television receiver e.g., if it uses an MTS stereo system, has at least two loudspeakers.
  • an acoustic sound reproducing apparatus for a first audio signal and having an input terminal for a second audio signal, a selector switch and at least one loudspeaker.
  • the at least one loudspeaker is driven by an output signal from one of the first or second audio signal through the selector switch.
  • the acoustic sound reproducing apparatus which in the exemplary embodiment is a television receiver, and the apparatus providing the second audio signal, which in the exemplary embodiment is a surround sound audio system, can commonly use a single loudspeaker or plurality of loudspeakers.
  • the at least one internal loudspeaker becomes part of the external loudspeaker arrangement for the surround sound system.
  • the loudspeakers are connected to their respective amplifiers and are connected to each other in series when they are connected by the selector switch to be driven by the external second audio signal.
  • U.S. Patent No. 4,146,745 shows loudspeakers connected in series.
  • the figure shows a block diagram and switch/loudspeaker arrangement according to aspects of the present invention
  • the figure shows a block diagram and switch/loudspeaker arrangement of an acoustic signal reproducing apparatus according to aspects of the present invention.
  • the acoustic signal reproducing system of the present invention includes a television receiver 10 and an audio signal reproducing apparatus 12 including loudspeakers 14.
  • Apparatus 12 has a selector switch 16, amplifiers 18, an external input terminal 20 and an amplifier output terminal 27 coupling respective amplifier output signals to respective output leads 22, 34.
  • the audio signal is supplied to input terminal 23 of respective amplifier 18 and respective output terminals 27 are connected to respective fixed terminals 24 of selector switch 16.
  • Leads 22 coupled to respective loudspeakers 14, connect to fixed terminals 25 of switch 16.
  • a signal at external input terminal 20 is connected to fixed terminal(s) 26 of selector switch 16.
  • Movable contact 28 is movable to position "A" for selection to internally drive respective loudspeakers 14 from amplifiers 18 through output signal leads 22, 34. Loudspeakers 14 are driven from the signal available at the external input terminal 20 when movable contact 28 is moved to position "B".
  • the external audio signal reproducing apparatus connectable to terminal 20 is a surround sound system having a center loudspeaker terminal for connection to a loudspeaker to receive a center L+R signal.
  • This center loudspeaker would be disposed between the left and right front stereophonic loudspeakers, e.g., the loudspeaker units of a surround sound system typically are each arranged at a front right position (FR), a front left position (FL), a front center position (FC), a surround right position (SR) and a surround left position (SL) respectively, in a manner known in the art.
  • loudspeaker(s) 14 can be used in place of any of the loudspeakers of the surround sound system or any other loudspeaker of any other type of sound system depending upon the signal provided at terminal 20.
  • the television receiver since the television receiver has stereo auxiliary audio input terminals 40, the television receiver can provide a stereo expansion effect (not shown) for a stereo signal coupled to such auxiliary input terminals 40 with the movable contact 28 switched in direction "A".
  • loudspeakers 14 connectable to external input terminal 20 of the television receiver 10 in switch position "B", provides that the speaker system 14 can be commonly used by both the television receiver 10 and the external program source.
  • the speaker system 14 has at least one loudspeaker unit, and in the exemplary embodiment has two loudspeakers because television receiver 10 is a stereophonic sound receiver. If the audio signal is provided by a surround sound audio system, the speaker system 14 can then serve as the front center loudspeaker (FC) as discussed above.
  • the loudspeakers 14 When the two or more loudspeakers 14 are disconnected from their respective amplifier 18 and are connected by switch 16 to terminal 20, the loudspeakers are connected in series with each other, i.e., their impedances are additive.
  • the power output is reduced by one half due to the doubling of the load impedance.
  • This has the benefit of permitting the loudspeakers to be powered by an external power amplifier which is rated to be higher in power output than each of power amplifiers 18, so that the loudspeakers will have an improved ability to not be damaged by such exposure to higher power.
  • This has the further benefit that the power rating of the loudspeakers need only to be matched to the power output of their respective amplifier 18, thus permitting the use of less expensive loudspeakers.
  • the amplifiers 18 can have differing output power and be greater in number than just two. Further, even though the present embodiment shows a single input terminal 20, a plurality of input terminals can be used for a plurality of external amplifiers, which need not have identical output power. Obviously, in such cases, switch 16 will change accordingly.
  • Muting circuit 30 When switch 16 is in the "center” position, i.e., switched in direction "B", loudspeakers 14 are no longer loading respective amplifiers 18. Accordingly, upon the switching to the "center” position of switch 16, a muting circuit 30 is actuated by switch 16. Muting circuit 30 is actuated in response to the connection of amplifier 18 output line 34 to the muting circuit 30 input line 36 at switch terminal 38. Muting circuit 30 applies a voltage and/or components coupled to ground (not shown), to a muting pin 32 of integrated circuit 33, to mute the integrated circuit or to place it in a standby mode, in a manner known in the art.
  • Amplifiers 18 are part of a TDA7490 integrated circuit made by STMicroelectronics headquartered in Geneva, Switzerland, and are 25 watt stereo Class D amplifiers.
  • the power supply, oscillator, and high frequency output filters are not shown in the figure and form no part of the present invention.
  • Switch 16 is a break-before-make slide switch but any other suitable switch can be used, e.g., a toggle switch, a relay.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Circuit For Audible Band Transducer (AREA)
  • Amplifiers (AREA)
  • Stereophonic Arrangements (AREA)

Abstract

There is provided an acoustic sound reproducing apparatus for a first audio signal and having an input terminal for receiving a second audio signal, a selector switch and at least one loudspeaker. The at least one loudspeaker is driven by an output signal from one of the first or second audio signal through the selector switch. As a result, the acoustic sound reproducing apparatus, and the apparatus providing the second audio signal, can commonly use a single loudspeaker or set of loudspeakers. When the external audio signal is selected, the internal loudspeaker(s) becomes part of the external loudspeaker arrangement for a surround sound system. When more than one loudspeaker is used, the loudspeakers are connected to each other in series when they are connected to be driven by the external second audio input signal instead of each being driven by their respective amplifiers. This permits the loudspeakers to be driven by an external amplifier having a higher power output than the internal power amplifier so that the loudspeakers will not be damaged when driven by a higher power external amplifier.

Description

FIELD OF THE INVENTION
The present invention relates generally to acoustic sound reproducing apparatus, and more particularly, to a loudspeaker arrangement and switching apparatus therefor.
BACKGROUND
A television receiver with its loudspeakers, and an audio sound system with its loudspeakers, are often disposed in a common listening room with the two not generally operated at the same time because the user cannot simultaneously listen to both when each has its own program source. Thus, the utilization efficiency of each of the various loudspeakers is reduced. For example, if the audio signal is a stereophonic signal reproduced in a multidirectional surround sound system such as a Dolbyä 5.1 sound system, five loudspeakers are used with one of the loudspeakers being a center loudspeaker which receives an L+R signal. The television receiver, e.g., if it uses an MTS stereo system, has at least two loudspeakers. Thus, because both systems cannot be simultaneously listened to when each has its own program source, the space efficiency of the listening room is also reduced.
One such attempt to improve the utilization efficiency of the various loudspeakers and to improve the space efficiency of the listening room is shown in U.S. patent No. 5,329,371.
SUMMARY OF THE INVENTION
There is provided an acoustic sound reproducing apparatus for a first audio signal and having an input terminal for a second audio signal, a selector switch and at least one loudspeaker. The at least one loudspeaker is driven by an output signal from one of the first or second audio signal through the selector switch. As a result, the acoustic sound reproducing apparatus, which in the exemplary embodiment is a television receiver, and the apparatus providing the second audio signal, which in the exemplary embodiment is a surround sound audio system, can commonly use a single loudspeaker or plurality of loudspeakers. When the external audio signal is selected, the at least one internal loudspeaker becomes part of the external loudspeaker arrangement for the surround sound system.
When more than one loudspeaker is used, the loudspeakers are connected to their respective amplifiers and are connected to each other in series when they are connected by the selector switch to be driven by the external second audio signal. This permits the loudspeakers to be driven by an external amplifier having a higher power output than the internal power amplifier, so that the loudspeakers will not be damaged when driven by such a higher power external amplifier. U.S. Patent No. 4,146,745 shows loudspeakers connected in series.
DESCRIPTION OF THE DRAWING
The figure shows a block diagram and switch/loudspeaker arrangement according to aspects of the present invention
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The figure shows a block diagram and switch/loudspeaker arrangement of an acoustic signal reproducing apparatus according to aspects of the present invention. The acoustic signal reproducing system of the present invention includes a television receiver 10 and an audio signal reproducing apparatus 12 including loudspeakers 14.
Apparatus 12 has a selector switch 16, amplifiers 18, an external input terminal 20 and an amplifier output terminal 27 coupling respective amplifier output signals to respective output leads 22, 34. The audio signal is supplied to input terminal 23 of respective amplifier 18 and respective output terminals 27 are connected to respective fixed terminals 24 of selector switch 16. Leads 22 coupled to respective loudspeakers 14, connect to fixed terminals 25 of switch 16. A signal at external input terminal 20 is connected to fixed terminal(s) 26 of selector switch 16. Movable contact 28 is movable to position "A" for selection to internally drive respective loudspeakers 14 from amplifiers 18 through output signal leads 22, 34. Loudspeakers 14 are driven from the signal available at the external input terminal 20 when movable contact 28 is moved to position "B".
In the exemplary embodiment, the external audio signal reproducing apparatus connectable to terminal 20, is a surround sound system having a center loudspeaker terminal for connection to a loudspeaker to receive a center L+R signal. This center loudspeaker would be disposed between the left and right front stereophonic loudspeakers, e.g., the loudspeaker units of a surround sound system typically are each arranged at a front right position (FR), a front left position (FL), a front center position (FC), a surround right position (SR) and a surround left position (SL) respectively, in a manner known in the art. However, it is within the contemplation of the present invention that loudspeaker(s) 14 can be used in place of any of the loudspeakers of the surround sound system or any other loudspeaker of any other type of sound system depending upon the signal provided at terminal 20. Additionally, since the television receiver has stereo auxiliary audio input terminals 40, the television receiver can provide a stereo expansion effect (not shown) for a stereo signal coupled to such auxiliary input terminals 40 with the movable contact 28 switched in direction "A".
Thus, loudspeakers 14 connectable to external input terminal 20 of the television receiver 10 in switch position "B", provides that the speaker system 14 can be commonly used by both the television receiver 10 and the external program source. The speaker system 14 has at least one loudspeaker unit, and in the exemplary embodiment has two loudspeakers because television receiver 10 is a stereophonic sound receiver. If the audio signal is provided by a surround sound audio system, the speaker system 14 can then serve as the front center loudspeaker (FC) as discussed above.
When the two or more loudspeakers 14 are disconnected from their respective amplifier 18 and are connected by switch 16 to terminal 20, the loudspeakers are connected in series with each other, i.e., their impedances are additive. Thus, for an external power amplifier having a transformerless output, which is the case for almost all contemporary audio power amplifiers, the power output is reduced by one half due to the doubling of the load impedance. This has the benefit of permitting the loudspeakers to be powered by an external power amplifier which is rated to be higher in power output than each of power amplifiers 18, so that the loudspeakers will have an improved ability to not be damaged by such exposure to higher power. This has the further benefit that the power rating of the loudspeakers need only to be matched to the power output of their respective amplifier 18, thus permitting the use of less expensive loudspeakers.
It is within the contemplation of the present invention that even though the present amplifiers 18 are alike since they are in the same IC, the amplifiers 18 can have differing output power and be greater in number than just two. Further, even though the present embodiment shows a single input terminal 20, a plurality of input terminals can be used for a plurality of external amplifiers, which need not have identical output power. Obviously, in such cases, switch 16 will change accordingly.
When switch 16 is in the "center" position, i.e., switched in direction "B", loudspeakers 14 are no longer loading respective amplifiers 18. Accordingly, upon the switching to the "center" position of switch 16, a muting circuit 30 is actuated by switch 16. Muting circuit 30 is actuated in response to the connection of amplifier 18 output line 34 to the muting circuit 30 input line 36 at switch terminal 38. Muting circuit 30 applies a voltage and/or components coupled to ground (not shown), to a muting pin 32 of integrated circuit 33, to mute the integrated circuit or to place it in a standby mode, in a manner known in the art.
Amplifiers 18 are part of a TDA7490 integrated circuit made by STMicroelectronics headquartered in Geneva, Switzerland, and are 25 watt stereo Class D amplifiers. The power supply, oscillator, and high frequency output filters are not shown in the figure and form no part of the present invention.
Switch 16 is a break-before-make slide switch but any other suitable switch can be used, e.g., a toggle switch, a relay.

Claims (8)

  1. Apparatus for switching (16) a plurality of loudspeakers (14) between amplifiers (18) of differing power output characterized by:
    a first means for coupling a plurality of loudspeakers (14) to a first plurality of power amplifiers (18) having a first power output;
    a second means for coupling the plurality of loudspeakers (14) to at least one of a second power amplifiers (18) each having a second power output greater than the first power output, and
    a means for changing the circuit configuration of the plurality of loudspeakers (14) according to the power output of the amplifiers (18) to which the plurality of loudspeakers (14) are coupled.
  2. Apparatus for switching (16) a plurality of loudspeakers (14) between amplifiers (18) characterized by:
    a first means for coupling a plurality of loudspeakers (14) to a first plurality of power amplifiers (18);
    a second means for coupling the plurality of loudspeakers (14) to at least one of a second power amplifiers (18), and
    a means for changing the circuit configuration of the plurality of loudspeakers (14) according to the power output of the amplifiers (18) to which the plurality of loudspeakers (14) are coupled.
  3. Apparatus for switching a plurality of loudspeakers (14) between amplifiers (18) characterized by:
    a first means for coupling a plurality of loudspeakers (14) to at least one of a first amplifiers (18) having a first power output;
    a second means for coupling the plurality of loudspeakers (14) to at least one of a second amplifiers (18) having a second power output, and
    a means for changing the circuit configuration of the plurality of loudspeakers (14) according to the power output of the amplifiers (18) to which the plurality of loudspeakers (14) are coupled.
  4. The apparatus of claim 3 characterized in that the first power output and the second power output are different, the first power amplifiers (18) are more than one, and the second power amplifiers (18) are more than one.
  5. The apparatus of claim 3 characterized in that the second power output is greater than the first power output.
  6. Apparatus for switching (16) a plurality of loudspeakers (14) between amplifiers (18) characterized by:
    a first means for coupling a plurality of loudspeakers (14) in a first circuit configuration to at least one of a first amplifiers (18) having a first power output, and
    a second means for coupling the plurality of loudspeakers (14) in a second circuit configuration to at least one of a second amplifiers(18) having a second power output.
  7. The apparatus of claim 6 characterized in that the apparatus is a television receiver (10).
  8. The apparatus of claim 6 characterized in that the individual loudspeakers (14) are rated at a predetermined power, each of the plurality of first power outputs are not the same but are equal to or less than the predetermined power rating of the individual loudspeakers (14), and each of the plurality of second power outputs are not the same but are greater than the predetermined power rating of the individual loudspeakers (14).
EP03290832A 2002-04-19 2003-04-03 Loudspeaker arrangement and switching apparatus therefor Withdrawn EP1355510A3 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US126743 1998-07-31
US10/126,746 US20030197811A1 (en) 2002-04-19 2002-04-19 Loudspeaker arrangement and switching apparatus therefor
US126746 2002-04-19
US10/126,743 US20030198358A1 (en) 2002-04-19 2002-04-19 Loudspeaker arrangement and switching apparatus therefor

Publications (2)

Publication Number Publication Date
EP1355510A2 true EP1355510A2 (en) 2003-10-22
EP1355510A3 EP1355510A3 (en) 2005-12-07

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP03290832A Withdrawn EP1355510A3 (en) 2002-04-19 2003-04-03 Loudspeaker arrangement and switching apparatus therefor

Country Status (5)

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EP (1) EP1355510A3 (en)
JP (1) JP2003319487A (en)
KR (1) KR20030083579A (en)
CN (1) CN1452435A (en)
MX (1) MXPA03003248A (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007116643A (en) * 2005-10-18 2007-05-10 Audio Design:Kk Audio signal processor
JP4779655B2 (en) * 2006-01-10 2011-09-28 ヤマハ株式会社 Stereo / monaural switching circuit and integrated circuit including the circuit
WO2016183763A1 (en) * 2015-05-18 2016-11-24 Hewlett-Packard Development Company, L.P. Audio and video processors
CN106790899A (en) * 2017-01-04 2017-05-31 上海傅硅电子科技有限公司 A kind of system that performance is put outside convenient evaluation and test handset audio

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5320224Y2 (en) * 1973-08-01 1978-05-27
JPS5836560B2 (en) * 1981-10-28 1983-08-10 松下電器産業株式会社 audio circuit device
NL8105371A (en) * 1981-11-27 1983-06-16 Philips Nv DEVICE FOR CONTROLLING ONE OR MORE TURNOVER UNITS.
US5329371A (en) * 1991-12-13 1994-07-12 Sony Corporation Loudspeaker system automatically switched between video and audio units
JPH05244685A (en) * 1992-02-28 1993-09-21 Toshiba Corp Television receiver

Also Published As

Publication number Publication date
JP2003319487A (en) 2003-11-07
EP1355510A3 (en) 2005-12-07
KR20030083579A (en) 2003-10-30
CN1452435A (en) 2003-10-29
MXPA03003248A (en) 2003-10-22

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