The 18LW1400 is an extended low frequency loudspeaker which sets an industry standard in 18" (460 mm) high performance transducers. It has been designed for use as a low bass or sub-woofer component, in either a reflex, bandpass or horn loaded configuration, in high power auditorium or arena loudspeaker systems. The transducer provides clean, undistorted low frequency reproduction at very high sound pressure levels and is able to withstand high power levels without damage. 18LW1400 design features include a large displacement suspension system which, in conjunction with a carbon fiber reinforced, straight ribbed cone and the Double Silicon Spider (DSS), assure an ultra-linear piston action and provide full control across the entire working range. A 100mm copper voice coil based on Interleaved Sandwich Voice coil (ISV) technology increases this control, providing high levels of thermal stability and durability. ISV technology is based on a high strength fiberglas former with half the coil wound on the outside and half on the inside and bonded together using unique high temperature resin adhesives. Hence, a balanced linear motor unit, exerting an exceptionally high force factor is achieved. The low distortion and unmatched sound quality of the 18LW1400 has been significantly improved by the Double Demodulating Rings (DDR) embedded in the pole piece of the magnetic structure. These have been designed to dramatically reduce the intermodulation and harmonic distortion while improving the transient response. Excellent heat dissipation has been achieved from the special basket design which incorporates air channels between the basket and the magnetic top plate. In addition, 8 air vents incorporated into the back plate are aligned with the voice coil to force air into the lower part of the gap. Maximum flux density in the gap is assured by the top and back plate design, resulting in a high BL factor. 18LW1400 is able to perform properly under inclement weather conditions. The exclusive cone treatment improves pulp strength and gives water repellent properties to both sides of the cone. In addition, the special treatment applied to top and back plates of the magnetic structure is far more resistant to the corrosive effects of salts and oxidization.