ESB Novemila Series 9.4M 4 Inch High End Cone Midrange Speaker 120w RMS Pair9. 4M 4" 100 mm High End Cone Midrange The magnet pole yoke, designed with magnetic flux analysis software, helps to achieve perfect and homogeneous saturation of the magnetic gap for the benefit of the voice coil stroke. This reduces distortion and increases dynamics. A pure copper ring placed in the air gap helps reduce the inductance of the voice coil so that it offers minimal resistance during high frequency reproduction. This means better high