Alpine R2-SB12V Single Type R2 12-in Subwoofer in Vented Enclosure - The new R2-Series subwoofers now feature larger, double-stacked magnets that contribute more motor force for deeper bass and tighter bass control compared to the previous generation. Drawing inspiration from the sleek, tapered lines and clean silver finish of the Alpine Halo Display, the R2-SB12V shares the same unique, curved edges outlined by a silver trim and a metallic front baffle for a matching system aesthetic.