SOUNDSTORM STS15D STEALTH DUAL VOICE COIL SUBWOOFERS [15", 1400 WATTS]  Description Soundstorm StS15D stealth dual voice coil subwoofers (15", 1400 watts) Poly coated paper cone Santoprene surround Dual high-Temperature kapton voice coils Imp: Dual 4_ 15" 1400W max Freq resp: 25 hz - 1 khz Efficiency: 1W/1M @ 96 DB Magnet structure: 140 oz Mounting depth: 7.63" Features Magnet structure: 140 Oz. Voice coil diameter/type: 2.5" kapton Mounting depth: 7-5/8" Santoprene surround Dual high temperature kapton voice coils