The ZV28-MK3 Dual 18” Active Subwoofer delivers GROUNDBREAKING Performance and Frequency Response with Ultra-Low Notes reaching 21Hz at -3dB (in pairs). Considered to be the Deepest High-Output Sub for its size, it also yields Smooth, Even, Accurate, Clean Output. This self-powered unit includes BASSSBOSS's signature precisely tuned DSP with multiple mode presets. Finish: Textured Black