7000 Watt Max Power 15 Inch Ferrite Mangnet Dual 1 or 2 Ohm Car Subwoofer SM15

15-inch Ferrite Mangnet Dual 1 or 2 Ohm Voice Coil ConfigurationPeak Power: 7,000 WattsRMS Power: 3,500 WattsCompetition Grade Non-Pressed Paper ConeStitched High Roll Foam SurroundAdvanced Air Flow Cooling System4″ High Temperature FAL Voice Coil in USAMagnet system type: high flux ferrite   453 ozFrequency Response: 33 - 300 HzSensitivity: 86.8dBFs: 33 HzRe: Dual 1 or 2 ΩQms: 7.38Qes: 0.64Qts: 0.59Mms: 554.6 grCms: 0.038 mm/NBl:16.63 n/aVas: 42.3 LSd: 730.6 cm2Xmax: 24.4 mmSM sub's built with tripe  high flux ferrite motor.  The motor utilizes Y35. As you can see from the photo on the T-yoke, this special shape increase transfer heat area, this design make the speaker more efficiency. The SM15 features an enormous 35mm (1.37") magnetic gap to ensure the coil is always under control. This motor drives a 4" diameter 4-Layer Flat Wire Aluminum Coil with an extremely long winding (3.3" long) wound on a thick aluminum former to incredible levels of excursion. We use 100% American made voice coils.we could take advantage of an extremely long 4-layer coil - the 4-layer coil keeps the mass and inductance down while allowing us to use such a long coil for incredible linear x-max while the powerful motor allows us to achieve the level of BL we desired