The Infinity Beta 20 bookshelf speaker is magnetically shielded and available in black and cherry finishes. Infinity's patented Ceramic Metal Matrix Diaphragm (CMMD ) technology delivers accurate performance with dramatically reduced distortion for incredibly lifelike sound. The Infinity Beta 20 also features an improved tweeter that delivers extended high-frequencies out to 40kHz. Perfect for SACD or DVD-Audio recordings. The tweeter is mounted in a patent-pending Constant Acoustic Impedance waveguide for improved high-frequency dispersion anywhere in the listening room.