Pioneer TS-WX130EA 8" Single 1 Ω Underseat Sealed Active Amplified Car Subwoofer 884938390859 | eBay
Amazon.com: JBL BassPro SL2 Active Underseat Car Subwoofer with Built in Amplifier - Under Seat 8'' Subwoofer Car with 125 Watt Power Amplifier : Electronics
Polk PSW111 Powered Subwoofer Reviewed - Future Audiophile Magazine