SB ACOUSTICS SB15NAC30-4, 15cm ALUMINUM CONE MIDBASS 4OHMFeatures Vented cast aluminum chassis for optimum strength and low compression Geometrically reinforced aluminum cone for optimum piston operation and reduced break-up Soft low damping rubber surround for improved transient response Non-conducting fibre 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 35 Hz Sensitivity (2.83 V / 1 m) 88.5 dB Mechanical Q-factor, Qms 5.65 Electrical Q-factor, Qes 0.32 Total Q-factor, Qts 0.30 Moving mass incl. air, Mms 10.8 g Force factor, Bl 4.8 Tm Equivalent volume, VAS 18.3 liters Compliance, Cms 1.91 mm/N Mechanical loss, Rms 0.42 kg/s Rated power handling* 50 W * IEC 268-5, T/S parameters measured on drive units that are broken in.
