Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
  • H04R9/06—Loudspeakers
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
  • H04R9/02—Details

Definitions

• the present invention relates to a loudspeaker assembly in particular, but not exclusively, for use in high fidelity sound reproduction.
• the cone is mounted such that the cone apex points in the opposite direction from desired sound waves.
• This chassis has to be strongly built and is a costly item.
• This bell-shaped chassis known just as the chassis, will nevertheless possess inherent weaknesses for loudspeaker performance due to its bell shape and the fact that the heavy magnet assembly is mounted on the rear of this chassis whilst the whole unit is mounted to the cabinet from the front outer flange.
• the chassis resonates and produces distortion. This results in increased materials and assembly time, which, in turn, increase the cost and weight of the loudspeaker.
• a tunnel effect is produced, which also introduces distortion.
• the object of the present invention is to obviate or mitigate these disadvantages.
• a loudspeaker assembly having a cone portion, said cone portion being mounted with its apex extending in the direction of intended sound travel, said cone portion being mounted by suspension means, such that said cone portion is caused to vibrate in response to electrical signals passed through a coil which is placed within a magnetic field.
• said loudspeaker assembly includes a magnet and a first pole piece, said first pole piece having a generally elongate portion, said magnet and said first pole piece being arranged such that the elongate portion extends along the cone axis.
• a second pole piece is connected to the magnet assembly, the second pole piece producing a magnetic circuit with a gap between the elongate first pole piece portion and the second pole piece, and the magnet assembly and the cone portion being mounted in substantially the same axis.
• the second pole piece is generally cone-shaped to reduce the length of the speaker coil former.
• said cone portion is supported by first and second cone suspension means, said first suspension means extending axially from the end of the elongate portion of the first pole piece, and said suspension means mounting the cone portion to the surround means.
• said second pole piece is mountable onto the loudspeaker surround and cabinet. Alternatively the loudspeaker is attached to the cabinet by an extension of rear or first pole piece.
• a coil is located within said cone, said coil being arranged around said extending member.
• said first pole piece includes a disc portion, said disc portion having at least one aperture therein to permit the passage of air there- through in response to movement of the cone portion.
• the apex of the loudspeaker cone is truncated, said apex being covered by a membrane, which may or may not permit the passage of air.
• the second pole piece and the magnet are secured to each other and to the surround by a ceramic anaerobic adhesive compound or by other suitable fastening means such as glues, screws, bolts etc.
• a loudspeaker assembly comprises a cabinet 2 and a speaker portion 3.
• the speaker portion 3 comprises a cone 4 which is mounted by a rubber surround 5 onto a pole piece 6.
• the pole piece 6 contains apertures 6a by which it may be secured to the cabinet or baffle 2.
• the baffle 2 has a circular aperture 2a in which is located a long-shaped magnet 7 of square cross section.
• a second pole piece 8 is secured to the magnet 7, the second pole piece 8 being disc-shaped and having an elongate portion 8a extending from the centre of the disc along the cone axis towards the apex 4a.
• the pole piece 8 has a plurality of apertures 8b therein to allow the passage of air from inside the cone to the exterior during movement.
• the cone 4 is mounted by two suspensions 9 and 10.
• Suspension 9 extends from portion 8a. which engages a stiffened porous felt pad 11 located at the apex 4a. of the cone.
• Suspension 10 is the standard type of spyder.
• An anaerobic ceramic adhesive compound is used to secure the suspension 10, the pole piece 6, and the magnet 7 together.
• the ceramic adhesive may also be used to secure the pole piece 6 to the magnet 7 and the magnet 7 to the pole piece 8.
• the loudspeaker coil 13 and electrical terminals 14 are located within the cone 4 and are mounted over the portion 8a and the suspension 10. In use, in response to electrical driving signals, the coil and cone 4 is caused to vibrate and sound energy is emitted principally in the direction A with accoustic dispersion which is generally dome-shaped and which has no tunnel distortion.
• the second pole piece 8 is mounted on the baffle 2.
• the first pole piece 6 is ring-shaped and has a rectangular cross-section.
• the suspension 10 is mounted on a ring-bracket 10a mounted on the pole piece 6. Otherwise the construction is the same as the first embodiment and like numerals denote like parts.
• the suspensions 9 and 10 may be arranged in a different manner although remaining consistent with the desired performance of the cone when driven, and the pole pieces 6 or 8 may be secured to the surround by any other suitable fastening means such as adhesive, screws or rivets.
• Advantages of the preferred embodiment of the invention include; distortion is reduced by eliminating the tunnel effect, the structural arrangement of a cone is retained, with improved dispersion characteristics and few of the disadvantages of a dome, the mechanism is coupled to the cabinet and surround directly close to or at its centre of gravity providing improved sound balance and audio characteristics such as linearity, and the braced heavy bell-shaped chassis is not required which makes such loudspeakers more economic.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Acoustics & Sound (AREA)
• Signal Processing (AREA)
• Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10525946

Family Applications (1)

Country Status (2)

Cited By (3)

Citations (8)

• 1982
  • 1982-10-19 EP EP19820903249 patent/EP0093736A1/de not_active Withdrawn
  • 1982-10-19 WO PCT/GB1982/000296 patent/WO1983001884A1/en unknown

Patent Citations (8)

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