B&C 21DS115 is a very high power 21" subwoofer for speaker subwoofer systems- B&C 21DS115 21" Subwoofer has a lightweight neodymium magnet - B&C 21DS115 21" high power speaker for speaker subwoofer
Clash of the titans: B&C Speakers 21DS115 vs RCF LF21N551. : r/diyaudio
Mini" Devastator with B&C 21DS115-4 | AVS Forum
B&C 21DS115-4 21" Professional Neodymium Subwoofer 4 Ohm