(19)
(11) EP 0 410 157 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
08.07.1992 Bulletin 1992/28

(43) Date of publication A2:
30.01.1991 Bulletin 1991/05

(21) Application number: 90112338.0

(22) Date of filing: 30.05.1984
(51) International Patent Classification (IPC)5: H04R 3/00, H04S 7/00, H03G 3/20
(84) Designated Contracting States:
BE DE FR GB IT LU NL

(30) Priority: 03.06.1983 US 500972

(62) Application number of the earlier application in accordance with Art. 76 EPC:
84106237.5 / 0127886

(71) Applicant: THAT Corporation
Marlborough, MA 01752 (US)

(72) Inventor:
  • Davis, Mark F.
    Medford Massachusetts 02155 (US)

(74) Representative: Findlay, Alice Rosemary et al
Lloyd Wise, Tregear & Co., Commonwealth House, 1-19 New Oxford Street
London WC1A 1LW
London WC1A 1LW (GB)


(56) References cited: : 
   
     
    Remarks:
    This application was filed on 28 - 06 - 1990 as a divisional application to the application mentioned under INID code 60.
     


    (54) Signal processing system for use with an audio reproduction system


    (57) A signal processing system for use with an audio reproduction system comprises a pair of input terminals for respectively receiving a pair of stereophonic audio input signals, a pair of output terminals for respectively providing a pair of stereophonic audio output signals and a pair of signals paths for respectively transmitting said two input signals between said input and output terminals. Means (408A, 408B) are coupled to each of said input terminals (250A, 250B) for detecting the signal energy levels of each of the corresponding input signals. The detected signal energy levels of said audio input signals are compared in means (428) for generating a difference signal in response to and as a function of said comparison. Means (270A, 270B) responsive to said difference signal are coupled between the system input and output terminals (250A, 250B, 278A, 278B) of at least one of said signal paths for varying the signal gain impressed on the input signal transmitted over said at least one path as a function of said difference signal so that said signal energy levels of said output signals are substantially balanced over relatively long periods of time.







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