Fostex FF225WK

FF-WK series bass-reflex full-range units: New paper-making method "double-layer paper cone" & "ridge-dome aluminum alloy center cap".

Features

Dual-layer paper cone, ridge-dome shaped aluminum alloy center cap, pocket-neck damper for even higher sound quality.

The FF-WK series is a full-range unit designed exclusively for bass-reflex, with the structure of the existing FF series completely revised and a new 10cm diameter unit added to the lineup.

The FF-WK series features a new paper-making method called “double-layer paper cone,” a ridge-dome aluminum alloy center cap, and a pocket-neck damper, which have realized reproduction of low frequencies with full power and high frequencies with no character, while maintaining a clear and realistic sound quality.

Double-layer paper cone/new up-rolled edge material

Two-layer papermaking is a unique technology in which cone paper is papermade in two steps to form a single sheet of cone paper with two layers: a base layer and a surface layer.

In the FF-WK series, the base layer is made of long-fiber (low-fatting) wood pulp, which provides high rigidity and moderate internal loss due to its sublime structure, and the surface layer is made of short-fiber (high-fatting) kenaf and bincho charcoal powder, which increases the propagation speed on the surface of the cone paper.

The edge shape is up-rolled to achieve a high stroke, and polycarbonate urethane foam is used as the material, which is a special blend of polycarbonate materials possessing the contradictory properties of high loss and high Young’s modulus.

The color tone on the surface of the cone paper of the FF-WK series is caused by bincho charcoal and no dyes are used.
Therefore, the color tone of the cone paper surface varies individually.

Ridge-dome aluminum alloy center cap / mechanical 2-way structure

Ridge-dome aluminum alloy center cap is used.

Strong resonance at specific frequencies is dispersed and weakened to reduce coloration in the high frequency range.

In addition, by directly connecting it to the voice coil bobbin, the reproduction bandwidth of the high frequency range is extended.

3-point adhesion system / Pocket neck damper

Three-point adhesion method is adopted, where the cone paper, damper, and voice coil are bonded at the same point.

By increasing the strength of the cone neck, the high frequency characteristics are improved.

In addition, a pocket shape in the damper neck section enables three-point bonding even while using a relay wire for the voice coil.

Faston 205 gold-plated connection terminals

In order to minimize changes in sound quality, gold-plated Faston 205 type terminals are used for input terminals.