The 11" Polyglass® cone woofer used in the CMS SUB is both very light and extremely rigid for a neutral and distortion-free response. This incredible weight-to-rigidity ratio is obtained by applying a thin layer of hollow glass spheres on top of a cellulose-based cone. The high excursion capabilities of the CMS SUB woofer offer tight and controlled bass, able to reproduce even the most minute detail. The CMS SUB woofer was designed to be extremely efficient, to make the most out of amplifier headroom, making sure that you can hear the slightest changes to compression settings.