... speaker of P Seres Reflex sub-bass system ,One 18" special bass unit ,Resulting in deep and power rich, pentrating bass ... . Features: Reflex sub-bass system One 18" special bass unit Resulting in deep and power rich, pentrating bass ... for amplifier 600W-1200W/8Ω Purpose: Concert with P, W series, use for Disco barperformance hall KTV roometc. Specification :Frequency Range ...