SB ACOUSTICS SB15NRX2C30-4, 15cm NOREX PAPER CONE MIDWOOFER 4OHMFeatures Vented cast aluminum chassis for optimum strength and low compression Proprietary cone material with natural fibers made in-house Soft low damping rubber surround for improved transient response Non-conducting fiber glass voice coil former for minimum damping Extended copper sleeve on pole piece for low inductance and low distortion CCAW voice coil for reduced moving mass Long life silver lead wires Vented pole piece for reduced compression Specs Nominal Impedance 4 Ω DC resistance, Re 3.1 Ω Voice coil inductance, Le 0.12 mH Effective piston area, Sd 82 cm2 Voice coil diameter 30.5 mm Voice coil height 15 mm Air gap height 5 mm Linear coil travel (p-p) 10 mm Magnetic flux density 1.0 T Magnet weight 0.54 kg Net weight 1.46 kg Free air resonance, Fs 34.5 Hz Sensitivity (2.83V/1m) 89.5 dB Recommended Frequency Range 40-4500 Hz Mechanical Q-factor, Qms 3.58 Electrical Q-factor, Qes 0.30 Total Q-factor, Qts 0.28 Moving mass incl. air,Mms 9.9 g Force factor, Bl 4.7 Tm Equivalent volume, Vas 20.5 liters Compliance, Cms 2.15 mm/N Mechanical loss, Rms 0.5 kg/s Rated power handling* 50 W * IEC 268-5, T/S parameters measured on drive units that are broken in.
