The BMW kit is available in two’sections’ Door Speaker upgrade – 4 Split kit and a replacement woofer kit 3-way component system with car-specific BMW upgrade speakers. Vibe OptiSound BMW 8 Woofers (PAIR) OPTISOUNDBMW8-V4. 8 woofer fits into the under-seat enclosure. Easiest plug & play installation due to car-specific baskets and harnesses. System can be used as passive or semi-active system. Approved compatibility with 1-series (F20/21), 3-series (F30/31/34/35), 4-series (F32/33), 5-series (F10/F11) 6-series (F12/13), X3 (F25). ESOTERIC CONE: Composite cone using paper, and wood fibres for a lightweight and rigid cone producing a natural vocal reproduction. NEODYMIUM MOTOR: All drivers feature powerful neodymium motors which deliver maximum magnetic force with shallow installation depth. SHALLOW SUBWOOFER: Custom tooled 8 inch subwoofer directly replaces the under seat installed factory speakers delivering improved bass performance. Type Car Specific Component. Speaker Size 8 (200mm). RMS Power 115 watts. Peak Power 345 watts. Minimum Input (RMS) 55 watts. Frequency Response 55Hz – 25kHz. Fitment 1-series (F20/21), 3-series (F30/31/34/35), 4-series (F32/33), 5-series (F10/F11) 6-series (F12/13), X3 (F25).