SB ACOUSTICS SATORI MW16PNW-4, 17cm PAPYRUS CONE NEODYMIUM WOOFER WHITE 4OHMFeatures Vented aerodynamic cast aluminium chassis for optimum strength and low compression Proprietary cone material with EGYPTIAN PAPYRUS™ fibres made in-house Soft low damping rubber surround for optimum transient response Advanced BIMAX spider for improved linearity Powerful optimized low distortion neodymium motor system Non-conducting fibre glass voice coil former for minimum damping Extended copper sleeve on pole piece for low inductance and reduced distortion CCAW voice coil for reduced moving mass Long life silver lead wires attached 180° apart for improved stability Vented pole piece and coil former for reduced compression High piston to chassis diameter ratio Gasket and bolt hole protrusions for reduced coupling to speaker cabinet Specs Nominal Impedance 4 Ω DC resistance, Re 3.4 Ω Voice coil inductance, Le 0.15 mH Effective piston area, Sd 119 cm2 Voice coil diameter 36 mm Voice coil height 17 mm Air gap height 5 mm Linear coil travel (p-p) 12 mm Magnetic flux density 1.17 T Magnet weight 0.13 kg Net weight 1.01 kg Free air resonance, Fs 28 Hz Sensitivity (2.83V/1m) 91 dB Mechanical Q-factor, Qms 4.5 Electrical Q-factor, Qes 0.29 Total Q-factor, Qts 0.27 Moving mass incl. air,Mms 12.2 g Force factor, Bl 5.0 Tm Equivalent volume, Vas 51.8 liters Compliance, Cms 2.62 mm/N Mechanical loss, Rms 0.5 kg/s Rated power handling* 60 W * IEC 268-5, T/S parameters measured on drive units that are broken in.