Energy CB-10 Bookshelf Speakers (Pair,Black) Exclusive Convergent source Module (CSM) features woofer and tweeter uniquely integrated for accurate sound and expansive soundstage. 5.5-Inch Woofer features patented Ribbed Elliptical Surround suspension for greater dynamics, output and lower distortion than conventional designs. Exclusive 1-Inch Hyperbolic Aluminum tweeter provides high frequency accuracy, high power-handling and wide dispersion Rigid, low-distortion MDF enclosure with attractive Black Ash Finish and Black High Gloss trim. Port plug & rubber bumpers for bookshelf use included, integrated 1/4-Inch- 20 insert for optional brackets / wall mounting.