The MS-50DR is Yamaha's most affordable drum monitor system. Designed specifically for electronic drums, the MS-50DR comes with one 50 watt 8" bass-reflex sub-woofer and two 20 watt satellite speakers with 4" woofer, 2" midrange and 1" tweeter. You can mount the satellites right on your drum rack. Controls include: Main Input Level Control; Woofer Level Control; Power Switch.