JL Audio 13TW5V24 13.5" 600W TW5v2 Series Shallow Mount Car Audio Subwoofer. Get em while they last for only $399.00
http://www.onlinecarstereo.com/CarAudio/p_35367_JL_Audio_13TW5V24.aspx
General Features:
- Nominal Impedance (Znom): 4 O
- Free Air Resonance (Fs): 27.61 Hz
- Electrical "Q" (Qes): 0.55
- Mechanical "Q" (Qms): 10.69
- Total Speaker "Q" (Qts): 0.526
- Equivalent Compliance (Vas): 2.13 cu ft / 60.31 L
- One-Way Linear Excursion (Xmax)* 0.433 in / 11 mm
- Reference Efficiency (no) 0.23%
- Efficiency (1 W / 1 m)** 85.63 dB SPL
- Effective Piston Area (Sd): 98.26 sq in / 0.0634 sq m
- DC Resistance (Re): 3.513 O
- Mounting Hole Diameter 12.5"
- Bolt Hole Circle: 13.5"
- Magnet Diameter: 6.75"
- Mounting Depth: 2.63"
- Driver Displacement: 0.052 cu ft