Fostex 20cm Cone Type Bass Reflex Dedicated Full Range Unit FF225WK

---------------------------------------------------------------------- Two-layer papermaking is a unique technology that makes one cone paper with two layers, a base layer and a surface layer, by making the cone paper in two stages. In the FF-wk series, long fiber (low degree of beating) wood pulp is used for the base layer, which has high rigidity and moderate internal loss due to its high structure, and short fiber (high degree of beating) kenaf and binchotan charcoal powder are blended for the surface layer to increase the propagation speed of the cone paper surface. In addition, the edge shape is up-rolled to achieve a high stroke, and the material used is a urethane foam specially blended with polycarbonate-based material that has the contradictory physical properties of high loss and high Young's modulus. * The color tone of the cone paper surface of the FF-WK series is due to binchotan charcoal and no dye is used. Therefore, the color tone of the cone paper surface varies from one to another. The center cap is made of aluminum alloy and shaped into a ridge dome shape. It reduces high-frequency coloration by dispersing and weakening strong resonance at specific frequencies. It also extends the high-frequency reproduction band by directly connecting it to the voice coil bobbin. The cone paper, damper, and voice coil are bonded at the same place using a three-point adhesive method. By increasing the strength of the cone neck, the high-frequency characteristics are improved. In addition, by providing a pocket shape in the damper neck, it is possible to bond the voice coil at three points even while using relay wires. To minimize changes in sound quality, gold-plated Faston 205 type terminals are used for the input terminals. (The gold plating may appear slightly dull at first glance, but this is normal.) The FF-WK series is a full-range unit designed exclusively for bass reflex, which has been a complete overhaul of the previous FF series structure and has added a new 10cm diameter to the lineup. By adopting a new paper-making method, the "two-layer paper-making cone," a ridge dome-shaped aluminum alloy center cap, and a pocket neck damper, we have achieved powerful low frequencies and characterless high frequencies while maintaining clear and realistic sound quality.