12-inch Pioneer Premier Subwoofer with sealed carpeted box. I used this along with my Pioneer amplifier (see related post) in my previous car to add a great, crisp bass effect to my car stereo. With the box your sub is protected and all you have to do is hook up the wiring to the back. 

Per manufacturer:

​1,000 Watts of music power (max.), Pioneer's Voice Coil Cooling System for lower sub temps and extended sound quality, and an aluminum insert that increases the rigidity of an already super-strong cone. If you're looking for a combination of skull-bombing power and precise musical control, the TS-W1241C is a great choice.

• 12" Premier VCCS PRO Component Subwoofer
• Nickel Coated Foamed IMPP (Injection Molded Polypropylene) Rigilite™ Composite Cone Woofer
• Aluminum Insert for Increased Cone Rigidity
• Dual-Layer Urethane Surround
• Direct Bobbin Mounted VCCS (Voice Coil Cooling System)
• Conex Damper with Damper Ring
• Lead Wires Integrated into Damper for High Reliability and Improved Power Transfer
• Projected Pole Yoke with Vented Pole
• High-Energy Ferrite Magnet with Bumped Back Plate
• Low-Q Design for use in Small Sealed Box (1.0 cubic foot recommended)
• 1000 Watts Max Music Power
• 500 Watts Nominal Power Handling
• Frequency Response: 15-2,000Hz
• Sensitivity (Efficiency): 88dB (1W/1m)
• 4Ohm Rated