Definitive Technology BP9020 High Performance Tower Speaker High-performance Bipolar tower speaker: 30 Hz - 22 kHz Powerful, Forward-Focused Bipolar speaker array for wide and immersive sound dispersion Integrated 8 powered subwoofer and bass vent Intelligent Bass Control offers enhanced bass while maintaining overall tonal balance Dolby Atmos and DTS:X compatible with A90 speaker accessory (sold separately),Includes only a single speaker.Max Sensitivity (1 watt @ 1 meter):92 dB