Infinity Reference 152 5-1/4 inch 2-Way Bookshelf Speakers Pair (Black) The combination of the acoustical science and patented designs found in the 1" (25mm) CMMD (Ceramic Metal Matrix Diaphragm) tweeter and advanced waveguide provides seamless sonic integration with the CMMD woofer while providing excellent high-frequency detail and smooth coverage across a wide listening area. Powerful bass is key to a high-quality sound experience and the strength of Infinity's extremely rigid woofer cones - constructed from CMMD (Ceramic Metal Matrix Diaphragm) - help to deliver a wide frequency range with minimal distortion. The advanced positioning and crossover network integration reduce harmful sonic artifacts that would otherwise detract from the overall performance of the loudspeaker. The end result is balanced, accurate sound with lifelike imaging and soundstage that brings the musical performance right into your home. The slim profile of the R152 is complemented with a rich, black woodgrain finish and hidden fasteners that provide for a clean look that blends easily with any dcor.