Ground Zero Titanium GZTW-12 12 30cm 350W Watt Dual Voice Coil Flat Subwoofer Bass Driver. The products of the TITANIUM line combine premium quality and high efficiency. A wide range of dedicated speakers meet most of the customer’s need. The amplifiers are equipped with sophisticated technology and encased by a posh heatsink with brushed titanium colour surface. 12? High quality subwoofer with high-strength, extremely flat IMPP cone. Diameter 30 cm / 12. Impedance 2x 2 Ohms. Power Recommendation 200 – 500 Watts. Voice Coil 50 mm / 2 copper. Excursion (Xmax) 32 mm. Mounting Ø 284 mm. Mounting Depth 97.5 mm. Resonance Frequency (Fs) 35.1 Hz. Overall Qaulity (Qts) 0.526. Air Volume (Vas) 53.1 L. Voice coil diameter mm / inch 50 / 2. Impedance (Ohm) 2 x 2. Re (Ohm) 4.0. FS (Hz) 35.1. Vas Liter / cu. 53.15 L / 1.88 cu. Le (mH) 1.993mH. Xmax (mm / inch) 30 / 1.18. SPL (dB 1w/1m) 89 dB. BL (TESLA – M) 15.5 N/A. Power (Watt RMS) 350. This includes the following areas: Jersey, Guernsey, Isle of Man, Isle of Wight, N.