Carbon Fiber Woofer with Plus One Architecture for Ultimate Sound Quality: Patented (US patent #7,548,631) Plus One cones provide more speaker-cone area than other similar speakers, which bring louder bass. Carbon fiber woofer material provide accuracy. Edge-driven Silk Dome Tweeter: Club SQ speakers have edge-driven silk dome tweeter, which delivers a broader and smoother high frequency response, never-harsh regardless of output level than more commonly used w-domes. Adjustable Tweeter Output Level: The Club SQ Speakers offer a tweeter output level control of 0dB or +3dB to optimize system linearity based on installation location. Incredibly Y40 Ferrite Magnet for Higher Sensitivity: The Club SQ Speakers use the Y40 Ferrite Magnet, which can bring higher sensitivity compared with the commonly Y30 Ferrite magnet.