Magnesium/aluminum alloy concave cones and square frames are the distinguishing features of the BS series. The B3S 3" full-range speaker's magnetically shielded design allows use in center channel and other multimedia applications. HiVi's Symmetric Motor Drive (SMD) technology reduces the voice coil's inductance modulation and back EMF, thereby improving the speaker's controllabilty and achieving impressively low distortion. Stamped steel frame and rubber surround. These drivers are capable of covering a wide portion of the audio spectrum, and are easy to install without the need for cutting complicated driver recesses.