This is an active two-way design built into a compact 11-litre reflex cabinet with a pair of ports on the front baffle. The driver complement consists of a 6.5-inch magnetically shielded doped-paper woofer and a 0.75-inch metal-dome tweeter with a magnesium diaphragm.

The tweeter is protected behind a wire grille and is set into the front baffle at the back of a shallow waveguide which ensures time-alignment with the woofer and smooth high-frequency dispersion. The very unusual woofer design is what first catches the eye, though, looking like it is intended to juice soft citrus fruits! In fact, this is Fostex´s HR (Hyper Radial) cone design, which is claimed to be extremely rigid while also being lightweight — the ideal combination required to provide very low bass distortion figures. Equally important is the way the cone is attached to the driver chassis, and we have another innovative design with its own acronym here too. This is the UDR Tangential Edge, which is said to eliminate unnecessary resonances. UDR stands for ´Up/Down Roll´ and describes the very odd-looking twisted effect of the surround.

We´re not done with the acronyms yet — there is another hidden away inside the cabinet. Standing waves inside rectangular speaker cabinets have always been a problem, and various techniques have been devised to deal with them. In the case of the NX6A, Fostex have combined long-fibre wadding with what they call HP Sound Reflectors. These appear to be multi-faceted inserts — one on the rear wall and one at the base of the cabinet — which are intended to scatter the sound internally, preventing standing waves (and hence resonances) from forming. The complete speaker is claimed to enjoy a frequency response of 55Hz-38kHz at the -6dB points.

The rear panel is equipped with three rotary controls: Volume, Lo EQ, and Tweeter Level, and two input connectors — a balanced XLR (+4dBu nominal sensitivity) and an unbalanced quarter-inch socket (-10dBV). The latter takes priority if both are connected. The Volume control turns the signal all the way down to silence, which is useful. The Tweeter Level control has a ±3dB range and simply adjusts the gain of the appropriate amplifier. The crossover frequency is unusually high, at about 7kHz, so this control really only affects the brightness of the top end. The Lo EQ is a peaking equaliser centred on about 55Hz with a ±3dB range again, and is intended to provide some compensation for boundary effects when placing the speaker close to rear walls or corners. The only other rear-panel facilities are the IEC mains inlet and rear-panel power switch. An LED on the front baffle illuminates when the speakers are powered.