The 15NLW9500 is an extended low frequency loudspeaker which sets a new industry standard in 15" (380mm) neodymium 4" voice coil high performance transducers. The 15NLW9500 has remarkable 35Hz downwards extension with 96dB average sensitivity and achievable peak power levels of 7kW. Extensive care has been taken in order to symmetries both mechanical and electromagnetic non linear behaviour. The transducer has been designed to cover the low frequency band in bass reflex configuration. Application range moves from studio monitors up to cinema subwoofers as well as professional sound reinforcing systems, where deep low frequencies are required. It can be used in enclosures from 90 liters in size upwards, with tuning frequencies of about 33Hz. The neo magnet assembly assures high flux concentration, low power compression and excellent heat exchange. This results in high levels of force factor and power handling with an optimum power to weight ratio. The heatsink has been specifically studied using F.E.A. simulators and the necessary heat transfer to the dissipative structure has been improved. The heatsink concept has been further improved by using an air-diffractor that offers high thermal capacity and has been designed to force air moved by the dust cap through the fins and cool it down. The direct contact between the heatsink and the basket, together with the magnetic structure, represents a fundamental improvement in heat dissipation, increasing power handling capabilities and lowering the power compression figure. The carbon fiber reinforced, straight-sided ribbed cone has been adopted in order to enable the transducer to withstand high loading designs as well as high power peaks. Maximum strength, smooth response and high displacement piston motion have been obtained using Double Silicon Spider technology (DSS) and a large excursion surround. The rubber suspension system has been designed to provide symmetric large signal behaviour throughout the whole working range, providing low harmonic distortion at different excitation levels.