KICKER C12 12" 400W Dual 4-Ohm Comp Car Audio Subwoofer Sub 10C12D4+Mono Amp+Kit Kicker 10C12D4 12" Comp 300 Watt Dual 4 Ohm Car Audio Subwoofer. Best-sounding, loudest bass for the buck. Dual 4 Ohm voice coil. Super-rigid, injection-molded cone with 360-degree back bracing. High-temp coil wire. Vented pole piece for heat dissipation. Strong steel basket with coil-cooling perimeter venting. Ribbed surround for strength at high excursion. Durable Spiralead tinsel leads. Tough, yellow double-stitching on surround. Handy spring-loaded terminals. Details:. Model C12D4. Size (IN.,CM) 12, 30.0. Impedance (OHMS) 4 DVC. Max Rec Amplifier Power (WATTS PEAK/RMS)* 400/200. Sensitivity (dB 1w/1m) 88.3. Frequency Response (Hz) 27-500. Mounting Depth (IN.,CM) 5-7/8, 14.8. Mounting Cutout (IN.,CM) 11, 27.9. Min Rec Sealed Box Volume (CU. FT., Liters) 1.25, 35.4. Max Rec Sealed Box Volume (CU. FT., Liters) 3.5, 99.1. Min Rec Vented Box Volume (CU. Ft., Liters) 1.75, 49.6. Max Rec Vented Box Volume (CU. Ft., Liters) 2.25, 63.7. Rockville RXD-M0 1200 Watt / 600 Watt RMS Mono Class D 1 Ohm Car Stereo Amplifier with Optical Coupler Technology. CEA Compliant Power Ratings : 1 Ohm : 300 Watts x 1 Channel &lt;1% THD+N . 2 Ohm : 200 Watts x 1 Channel &lt;1% THD+N. 4 Ohm : 150 Watts x 1 Channel &lt;1% THD+N . RMS Power Ratings : 1 Ohm : 600 Watts x 1 Channel. 2 Ohm : 400 Watts x 1 Channel. 4 Ohm : 300 Watts x 1 Channel. Peak : (The amount of power the amplifier can produce for a split second at the loudest part of a song. 1 Ohm : 1200 Watts x 1 Channel . 2 Ohm : 800 Watts x 1 Channel. 4 Ohm : 600 Watts x 1 Channel. High-Speed MOSFET Power Supply. Optical Coupler Class D Technology. Studio-Grade Bipolar Output Stage Transistors . Now exclusively with Professional Peak Limiter Circuitry which guarantees distortion free musical playback at all levels. Fully Adjustable 12dB / Octave Crossover with Differential Circuitry. Low Pass Filter : 50Hz - 250Hz. Subsonic Filter : 15Hz - 55Hz. Phase Control Switch. Full IC-Controlled Protection Circuitry. Remote Dashboard Subwoofer Control. Fully Adjustable 12dB Bass Equalizer. Mute and Delay Soft Start System. RCA Preamp Line Output. 8 Volt Preamp Circuitry. Status Mode LED Indicator. Minimum THD at Rated Power : 100dB.