US 5,400,408 AGranted

High performance stereo sound enclosure for computer visual display monitor and method for construction

AssigneeApple Computer, Inc.

InventorsDavid A. Lundgren, William V. Oxford

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Abstract

A high quality stereophonic sound enclosure system high resolution intended for computer visual display monitors employing cathode ray tubes (CRTs) having a vertical aperture grill, and methods for construction of same. The aperture grill has a natural frequency centered within the musical scale. The stereo speaker system comprises a ported speaker enclosure within which are mounted two conventional cone speaker assemblies. A stereo audio amplifier and control unit for controlling the audio signals delivered to the speakers is mounted within the speaker enclosure. The speaker enclosure is internally mounted within the monitor with a minimum number of attachment members incorporating vibration isolation material to remove vibration components near the natural frequency of the aperture grill. The speaker enclosure is internally reinforced to reduce structural deformations which contribute to airborne transmitted vibration within the monitor housing when the speaker system is operating.

Claims15

Dependent claims

In a high resolution visual display monitor comprising a cathode ray tube (CRT) including an aperture grill having a first natural frequency substantially within a musical bandwidth, wherein said monitor is coupled to receive a plurality of video and audio signals from a central processor unit within a digital information processing system, a stereo sound system comprising:

a hollow body subtending an enclosed volume;
said hollow body further comprising a rigid unit including a first plurality of intersecting rib members for resisting deformation of said hollow body;
an audio speaker arrangement affixed to said hollow body, said audio speaker arrangement coupled to receive said audio signals and generating in response thereto a plurality of sound waves;
a tuned port formed within said hollow body and having a second natural frequency less than said first natural frequency of said aperture grill and exhausting a band of selected low frequency sound waves from said hollow body;
and
a plurality of vibration isolation members seated on a corresponding plurality of isolation-mounting surfaces formed in said hollow body and compressively disposed between said hollow body and said monitor when said hollow body is mounted within said monitor;
said vibration isolation members having a third natural frequency substantially equivalent to said second natural frequency and substantially vibrationally isolating the audio speaker arrangement from the aperture grill.

4 more elements

In a high resolution visual display monitor comprising a cathode ray tube (CRT) including an aperture grill having a first natural frequency substantially within a human hearing, wherein said CRT is coupled to receive a plurality of video and audio signals from a central processor unit within an audio-visual information processing system, a method for supporting a stereo sound system within said monitor comprising the steps of:

providing a hollow body subtending an enclosed volume;
said hollow body further comprising a rigid unit including a plurality of intersecting rib members for resisting deformation of said hollow body;
coupling a plurality of audio speakers to said hollow body, said audio speakers coupled to receive said audio signals and generating a plurality of sound waves;
forming a tuned port within said hollow body and having a second natural frequency less than said first natural frequency of said aperture grill and exhausting a band of selected low frequency sound waves from said hollow body;
and
mounting a plurality of vibration isolation members having a third natural frequency substantially equivalent to said second natural frequency on a corresponding plurality of isolation-mounting surfaces formed in said hollow body and maintaining
said vibration isolation members in a state of compression between said hollow body and said monitor such that
said vibration isolation members substantially vibrationally isolate the audio speaker arrangement from the aperture grill.

5 more elements

Dependencies are inferred from the claim text.