(19)
(11) EP 0 456 416 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
25.11.1992 Bulletin 1992/48

(43) Date of publication A2:
13.11.1991 Bulletin 1991/46

(21) Application number: 91303981.4

(22) Date of filing: 02.05.1991
(51) International Patent Classification (IPC)5: H04R 1/28
(84) Designated Contracting States:
DE FR GB NL

(30) Priority: 11.05.1990 JP 121625/90

(71) Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Kadoma-shi, Osaka-fu 571 (JP)

(72) Inventors:
  • Mitsuhiko, Serikawa
    Hirakata-shi, Osaka-fu 573 (JP)
  • Hiroyuki, Naono
    Yawata-shi, Kyto-fu (JP)
  • Hara, Masayuki
    Katano-shi, Osaka-fu (JP)
  • Yukiyoshi, Atsushi
    Neyagawa-shi, Osaka-fu (JP)
  • Tanaka, Syouji
    Kobe-shi, Hyogo-ken (JP)
  • Hotta, Masaji
    Katano-shi, Osaka-fu (JP)

(74) Representative: Crawford, Andrew Birkby et al
A.A. THORNTON & CO. Northumberland House 303-306 High Holborn
London WC1V 7LE
London WC1V 7LE (GB)


(56) References cited: : 
   
       


    (54) Loudspeaker system


    (57) A dip-free plane flat pressure level-frequency characteristic is realized by a cascade bass-reflex loudspeaker system provided with a port-containing partition or partitions in a speaker cabinet to divide a space inside thereof into two internal acoustically connected spaces by establishing in either internal space a Helmholtz resonator possessing the same resonant frequency as a second antiresonant frequency to absorb a negative-phase sound radiated from the port to the outside of the cabinet, thereby eliminating a dip in the sound pressure-level frequency characteristic due to the second antiresonance unique to a cascade bass-reflex loudspeaker system.






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