The flagship of the Polk RTIA9CHY RTi A series, with three 7" bass drivers and two 5 ¼" midrange drivers, this speaker rocks. Make RTi A9 the main anchor to your home theater or music system. With a mind blowing 500 watt power capacity, these speakers can take everything you dish at them. Watch high octane action movies in their full glory, or listen to an intimate jazz performance at a lower volume. Rti A9's unique midrange section is also sealed off from the rest of the cabinet, giving the clearest, most articulate midrange in the entire series. RTi A9 sounds rich and full without ignoring detail.