Nakamichi NSW-Z1206D4 is a 12" (316MM) DVC SUBWOOFER with a nominal impedance of 4 ohms. It has a power rating of 600W RMS, a sensitivity of 84 + 3 dB (1Tw/1m), and a frequency range of 45~1.5k Hz. The voice coil diameter is 260 mM, the voice coil length is 40 mm, and the air gap height is 8 mm. The magnet dimension is D160 x 20 mm, and the resonant frequency is 30 + 3 Hz. The D.C. voice coil resistance is 3.6 ohms, the mechanical quality factor is 4.8, the electrical quality factor is 1.4, and the total quality factor is less than 1. The equivalent air volume to Cms is 87MPL