Alpine PWD-X5 Compact powered 8" subwoofer with digital signal processor and 5-channel amp (25 watts RMS x 4 + 165 watts RMS x 1) at Crutchfield
Free Shipping 3 Sets Alpine Pwe-10800c Under Seat Car Active Amplified Powered Subwoofer System 160w Max Mobile Media Solutions - Speakers - AliExpress
Best Under Seat Subwoofer in 2021 - Top 5 Picks For Any Budget! - YouTube