active speaker PP-0312 12"2 WAY SPEAKER BOX Subwoofer Magnet 50 oz Voice Coil 2.5"KSV Frequency Response 50HZ 18KHZ(-10dB) Impedance 8 Ohm RMS power 180w Dimensions(w×d×h) 42×31×58.5 cm Tweeter 34mm Ti.Diap. Driver 13.5 oz 8 Ohm Special design Blue LED indicator on front panel Amplifier(A) PP-0312A Impedance 4Ohm Voltage 110-230V/AC/60-50Hz RMS Power 150W Amplifier(B) PP-0312AU Special function USB Slot and LCD screen Amplifier(C) PP-0312AUES Special function USB/SD Slot,LCD screen ,and EQ