Patent ID: 6775383
Filing Date: 2004-08-10
Classification: B64G,F16F

Abstract:
A stand-alone adaptive vibro-acoustic damper system for a wall-enclosed volume having time-varying acoustic resonance, said system comprised of:a diaphragm matched to the acoustic impedance of said volume; a voice coil attached to said diaphragm; a diaphragm motion sensor attached to said diaphragm providing a voice coil input signal; a magnet surrounding said voice coil, such that said magnet and said voice coil provide a varying electromotive force for maintaining optimal coupling of said diaphragm to said time-varying acoustic resonance in response to said voice coil input signal; a surround-type support apparatus to support said diaphragm; a battery power supply; a vented case to hold said magnet, voice coil, diaphragm support and battery power supply; a flexible base of variable stiffness attached to and supporting said case and attached to the wall of said enclosed volume; a wall motion sensor attached to said flexible base providing a base input signal responsive to motion of the wall of said enclosed volume; means for varying the stiffness of said flexible base in response to said base input signal; and means for varying said voice coil and base input signals such that said time-varying acoustic resonance within said wall-enclosed volume are minimized.