QD AUDIO LF18G-1800 5′ VOICE COIL 1800 WATT 8 OHEM Incredibly linear frequency response characteristics, extreme high power handling while generating the lowest harmonic distortion of any comparable 18-inch trasducer wtihin its application range. The LF-18G 1800 uses a fibre loaded cone assembly along with a high excursion triple roll,constant geometry surround. A fully optimised T-pole design generate the minimum amount of flux modulation. The T-pole also features Precision’s spaced gap demodulation technology, progressively braking the voice coil, providing a much smoother transition for the moving mass as it reachees its maximum excursion limits.Forced air venting system.