Monster Rockin Roller X PROBig Sound. Built to Roll. The next gen Monster Rockn Roller X Pro delivers powerful, room filling sound with 1100W peak power, a 15 woofer, and a 1. 5 tweeter for deep bass and clear highs. Whether its a backyard gathering, tailgate, party, or event, this speaker commands attentionindoors or out. With up to 10 hours of battery life, the music keeps going as long as the party does. 1100 Watts of Power with a 15 Subwoofer and 1 Tweeter Bluetooth 5. 4