Patent ID: 7206425
Filing Date: 2007-04-17
Classification: H04R

Abstract:
1. A completely inside the ear canal (“CIC”) speaker comprising: a housing adapted for insertion into an ear canal, wherein the housing has an open front portion and a closed rear portion; a diaphragm of diameter “D”, wherein the diaphragm is connected to housing by a suspension, wherein the diaphragm and the closed rear portion define a rear cavity volume, wherein when the housing is inserted into the ear canal, the diaphragm and an ear drum define a front cavity volume, and wherein the front cavity volume and the rear cavity volume are approximately equal; a magnet assembly of length “M” measured along the dimension orthogonal to the diaphragm, the magnet assembly defining a cylindrical magnetic gap; and a voice coil having a first portion rigidly attached to the diaphragm and a second portion placed in the cylindrical magnetic gap, the voice coil having a length “L” measured along the dimension orthogonal to the diaphragm surface; wherein M>L and the ratio defined by D/M is less than one.