18-in next generation high performance subwoofer, specifically designed for high SPL very low frequency applications in either a reflex, bandpass or horn loaded configuration - Walmart.com
Eighteen Sound 18 Sound Speaker 10W402 10 Inch Woofer Speaker NEW | eBay
Eighteen Sound 10NMB420 High Output Transducer 10" Speaker - Single - 18 Sound | Reverb
Eighteen Sound 15MB700 - 15-Inch 400-Watt AES High Output Woofer