Power Dynamics PDY215S 15" Passive PA Subwoofer - 900W
The Difference Between a Passive and Powered Subwoofer
AUNA Two Hi-Fi Subwoofers, 80W RMS Passive Subwoofer Speaker for Home Theatre System, Big Bass, Compact Design, 100W Max Hifi System, AUX Input for MP3 & CD Players, Volume Control, Auto-Off :
FBT Muse 218S Dual 18-inch Passive Subwoofer
Focal Car Audio PSB200 8" Passive Subwoofer with Sealed Subwoofer Encl – Car Audio Centre