pkg Sundown Audio (2) E-12 V3 D4 12" Subwoofers + SAE-1000D Monoblock Amplifier RMS Power = 500-watts | Xmax = 14mm one-way by 70% BL | Vented magnetic gap | Vented pole piece with optimized geometry Black Aluminum 2.5 voice coil former for superior heat dissipation | High Temperature 4-Layer copper voice coil wire | Spring Loaded Terminals | Stitched-On Mini-XL Tinsel Leads to prevent fatigue and failure | Box Recommendations: Sealed: 1.0 ft^3 | Ported: 1.75 ft^3 | Displacement: 0.12 ft^3 | Depth: 6 1/2" | Outside Diameter: 12 1/4" | Cut-Out: 11 1/8" | Recommended Tuning: 32hz | Recommended Port Area: 28 in^2 SAE-1000D V2 | Digital Class-D Linkable Monoblock Amplifier | MOSFET PWM Power Supply | 1-Ohm Stable Load | 24dB/Oct - Variable Low Pass Filter | 24dB/Oct - Variable Subsonic Filter | 12dB/Oct - Variable Bass Boost | 180 Degree Variable Phase Shift | 4-Way Protection Circuit (Thermal, Voltage Speaker Short and DC Offset) | Wired Remote Control Rated Power Output (Tested Voltage 14.4 Volts): RMS Power 2-Ohms Linked: 2000W | RMS Power 1-Ohm Mono: 1000W | RMS Power 2-Ohm Mono: 500W | RMS Power 4-Ohm Mono: 250W | Low Pass Frequency Crossover: 30Hz - 250Hz | Subsonic Filter: 10Hz - 50Hz | Bass Boost - 45Hz: 0-12dB Phase Shift Control: 0-180 Degree | Frequency Response: 10Hz - 250Hz | Input Sensitivity: 6 - 0.2 Volts | Signal Noise Ratio: &gt;100dB | THD 4-Ohms: &lt;0.5% | Efficiency 4-Ohms: 86% | Recommended Fuse Rating: 40A x 3 | Dimensions: 13.1" L x 8.5" W x 2.3" H