Yorkville EXM-MOBILE-12 Battery-Powered Compact Speaker, 12” Woofer, 3-Channel Mixer The Yorkville Excursion Series EXM-MOBILE-12 is an ideal solution for anyone needing a portable PA system. It can run off of the internal battery when AC power is not available and has a built-in 3-channel mixer with Bluetooth plus digital effects. With its 12-inch woofer, 1-inch horn driver, and 60 watts of output power the EXM-MOBILE-12 is perfect for small performances and presentations in any location.