2000w 18inch subwoofer martin audio passive 18'' technics subwoofer| Alibaba.com
Technics SB-AS500 Active Subwoofer
TECHNICS SB-W33 SUBWOOFER SYSTEM
My Technics 1979 amplifier has two channels, L and R, with no subwoofer input. Is it 2 or 2.1, and can I attach a sub woofer? - Audiophile Bits & Pieces - Quora