AnthonyO 10+ year member
Budget Banger Connoisseur
I know you said 21” but this 18 is beast
https://store.soundsolutionsaudio.com/warden-18-3500w-subwoofer-by-incriminator-audio/
https://store.soundsolutionsaudio.com/warden-18-3500w-subwoofer-by-incriminator-audio/