Critical Mass Audio SS122 12 ?

A pair of Critical Mass Audio SS122 12" Subwoofer imported from the USA late last year for 1500 Pounds. Critical Mass Audio is also used by people like Snoop Dogg, Wayne Brady, Busta Rhymes & Ludacris etc... These subs are like new condition. The box is tuned to 34hz. I have had subs in life like JL, MTX, Cerwin Vega etc... But these sound incredible! Was also used very little use due to being installed in my second/weekend car! Check these links: http://www.youtube.com/watch?v=uffvqZHr63o http://www.criticalmassaudio.com/products.html Specs: Subwoofer Size: 12" RMS Power handling: 500 Watts Peak Power handling: 1000 Watts Recommended Box Volume: 1.2 cuft(Sealed) Motor Type: Custom High-Output heat dispersion CM design Voice Coil Type: High Temp capacity Long Throw CM design Voice Coil Diameter: 2" Voice Coil Impedance: 2 ohm nominal Xmax (one-way linear excursion): 15 mm (More than 1.5" peak-to-peak) Maximum Excursion: 23 mm (about 2" peak-to-peak) Sensitivity: 95.08 db (2.83V / 1m) Fs (Klipple-LSI): 24.5 Hz Qts (Klipple-LSI): 0.41 Vas (Klipple-LSI): 99.09 Liters Asking £750 O.N.O.