If you are seeking intensely powerful sub-bass that compromises nothing in terms of sound quality, the 12W6v3 is your ultimate ally. This highly advanced subwoofer driver offers several technologies shared with the flagship W7AE subwoofers to provide powerful advantages in motor linearity and suspension behavior. These combine with a very efficient cooling circuit to deliver reduced distortion and outstanding dynamic balance.
The 12W6v3 is best used with amplifier power in the 200W - 600W range and is optimized to operate in a sealed enclosure with only 1.0 cu. ft. (28.3 l) of air space. 
Authorised UK Dealer for JL Audio
Free Air Resonance (Fs): 25.0 Hz
Electrical “Q” (Qes): 0.480
Mechanical “Q” (Qms): 7.100
Total Speaker “Q” (Qts): 0.450
Equivalent Compliance (Vas): 2.82 cu. ft. / 79.9 liters
One-Way, Linear Excursion (Xmax)*: 0.65 in. / 16.5 mm
Reference Efficiency (no): 0.250%
Efficiency (1W/1m)**: 85.9 dB SPL
Effective Piston Area (Sd): 77.8 sq. in. / 0.0502 sq. m.
DC Resistance (Re): 6.75 ohm***
Nominal Impedance (Znom): Dual 4 ohm
Thermal Power Handling (Pt): 600W
Driver Displacement: 0.090 cu. ft. / 2.5 liters
Net Weight: 19.4 lbs. / 8.8 kg