The 21NLW9601 is a 21 inch neodymium high performance transducer. It is the evolution of the 21NLW9600 speaker. The transducer is suitable for high loading, ultra-low frequency horn loaded as well as bandpass subwoofer designs. For optimum results recommended amplifier should be able to deliver 3600 Watt program power without clipping. At the heart of the transducers stands the improved Triple Silicon Spider (TSS) lets the 21NLW9601 being able to control the moving mass with exceptional linearity, showing an exceptional stability of mechanical parameter values in the long term. The transducer design features include a high performance large displacement suspension system for improved cone control even at very high level of SPL matching. The state-of-the-art 5,3" diameter ISV copper voice coil shows a inside-outside split winding, four layers design, enabling the 21NLW9601 to handle up to 3600W program power. Bl force factor as well as all electro-dynamic parameters are linear within the working range. This, together with the high excursion behavior - 70 mm before damage, ±14 mm linear Xmax - makes the 21NLW9601 an extremely low distortion, highly dynamic transducer. The already low distortion and sound quality are further improved by an aluminum Single Demodulating Ring (SDR technology) that flatten impedance and phase with a constant power transfer. The 21NLW9601 has been developed after intense FEA and fluido-dynamics simulation and testing, focusing on dissipating the heat generated by the powerful 5.3" coil. Special attention was given to the optimization of air flow into the gap without introducing audible noise. A special low density material air diffractor placed into the backplate acts as a cooling system, increasing the power handling capability and lowering the power compression figure. Weight reduction was a key development aspect of the 21NLW9601, resulting in a net value of 14kg (30,9b). The carbon fiber reinforced, straight ribbed cone shows a proprietary resin treatment for extra pulp strength and water repellent properties. A special coating applied to both the top and back plates makes the transducer far more resistant to the corrosive effects of salts and oxidization.