Mackie HR824 Active Studio Monitor (Single) 150 watt power amp for the woofer and a 100 watt power amp for the tweeter. Switchable rear controls include acoustic space (room size) and high freq/low freq roll-off. 8.75" low-distortion LF transducer &amp; passive-radiator provide tight bass response down to 37Hz 1" HF transducer. XLR, 1/4" and RCA inputs. Non-fatiguing through hours of use. THX pm3 approved for 5.1 and 7.1 surround mixing and playback.