The 31NFR is a high efficiency, (84dB 1watt / 1 meter) 3-inch full range speaker with very linear frequency response characteristics and high power handling capability. The 31NFR uses a lightweight anodized aluminum cone assembly along with a NBR single roll geometry surround. The combination provides high efficiency, extended high frequency response and sustained output under variety of conditions, while generating low harmonic distortion over the working range of this speaker. Magnetic circuit designREDCATT engineers have developed neodymium based magnetic circuit with small form factor, high integrity magnetic flux gap and low distortion characteristic. The magnetic circuit design is optimized to generate the minimum amount of flux modulation, providing exceptional stability. Copper demodulation cup is assembled over the t-pole.