M&K Sound S150II THX Ultra2 Certified Right or Center Channel Monitor-Each (Black) You will receive:1 S150II-R Loudspeaker Three high-quality 1 polymer coated silk soft-dome, ferrofluid cooled dual-magnet tweeters are aligned in a vertical array, each utilizing a unique, specially designed polymeric-damped rear cavity to further enhance its superior sound. The S-150MKII THX Ultra2 dual high-performance 5 1/4 mineral-filled polypropylene cone, magnetically shielded, dual-magnet cast basket woofers produce powerful, richly detailed low frequencies. Based on M&Ks Professional Monitors and designed for music