Massive Audio Amplifier E3F - 1,500 Watts RMS x 1 @ 1 Ohm Full Range Mono Block Amplifier
Kicker 47KEY500.1 Compact mono subwoofer amplifier with automatic tuning DSP — 500 watts RMS at 1 ohm at Crutchfield
Amazon.com: Fosi Audio M04 Subwoofer Amplifier for Home Theater Mono Channel Digital Class D Integrated Power Amp for Passive Speakers Subwoofer Rated 100W MAX : Electronics