Speaker Specifications Power Pe 500 / 750 RMS/Nom DC resistance Rdc 3,7 Ω Nominal impedance ZN 4 Ω Resonance frequency fs 27 HZ Voice coil diameter 2,5 inch Xmax + - 12,5 mm Mechanical Q factor Qms 6,32 Electrical Q factor Qes 0,40 Total Q factor Qts 0,38 Moving mass Mms 135 g Effective piston area Sd 510 cm2 Mechanical resistance Rms 3,95 Kg/s Compliance Cms 0,26 mm/N Force factor BL 13,95 Tm Equivalent air volume Vas 93,72 dm3 SPL 2,83V/1m 92 dB