Class D Digital Power Amplifier Audio Module Active Subwoofer Amplifier Board, Amplificador Subwoofer 500w Subwoofer Board - Home Theater Amplifiers - AliExpress
AudioControl RS 1000 1,000-watt subwoofer amplifier with DSP at Crutchfield
Do subwoofers need amplifiers? - Quora
Amazon.com: Fosi Audio M03 Subwoofer Amplifier 200 Watt Mini Mono Audio Amp Full-Frequency and Sub Bass Switchable Amplifier One Channel Home Theater Single Power Subwoofer Amp : Electronics
PSB-200 Subwoofer Amplifier with Crossover / Phase Control - 200W – Soundavo
1000W Class D Subwoofer Amplifier SMP-1000 | OSD Audio