Patent ID: 6563929
Filing Date: 2003-05-13
Classification: H04R

Abstract:
A woofer to receive an AC input signal from the audio output of an audio amplifier, said woofer comprising:a magnetic structure including at least one permanent magnet and at least one voice coil spaced from said permanent magnet, said voice coil receiving an alternating current so as to become an electromagnet having polarities that change with the changing polarities of the alternating current; and a hollow conical shell from which sounds are emitted to a listener, said hollow conical shell having an outside frame fixedly attached to said magnetic structure and an inside cone coupled to said voice coil, said electromagnetic voice coil being pulled towards said permanent magnet when the polarities of said permanent magnet and said electromagnetic voice coil are opposite such that the inside cone of said hollow shell is displaced in a first direction, and said electromagnetic voice coil being pushed away from said permanent magnet when the polarities of said permanent magnet and said electromagnetic voice coil are identical such that said inner cone is displaced in an opposite direction.