Klipsch R-51PM Powered Bookshelf Speakers (Pair) The Klipsch R-51PM Powered Bookshelf Speakers are a 2-way Powered Bookshelf speaker system with Bluetooth wireless connectivity. Klipsch R-51PM Powered Bookshelf Speakers built-in amplifier provides 120-watt RMS( 240-watt Peak). The built-in power amplifier saves space & eliminates the need to connect Klipsch R-51PM Powered Bookshelf Speakers to a stereo receiver or external power amp. The Klipsch R-51PM 2-Way Powered Bluetooth Bookshelf Speakers