Floorstanding loudspeakers — Mission ZX-4

The ZX-4 is the middle floorstander of three in the ZX series from British brand Mission, which Mission presents as the most technically advanced range in its catalogue. The series runs to eight models - the ZX-1 and ZX-2 standmounts, the ZX-3, ZX-4 and ZX-5 towers, two centre channels and an on-wall surround. Unlike the two-way ZX-3, the ZX-4 is a passive three-way tower with dedicated drivers for bass and midrange. Its UK launch price was GBP 1,299 per pair, and the cabinets are finished in gloss black or gloss white lacquer.

Key specs that matter

Two 130 mm aluminium cone woofers handle the bass, a third 130 mm aluminium cone covers the midrange, and a 38 mm ring dome looks after the top end, with crossover points at 530 Hz and 2.7 kHz. Mission quotes a response of 40 Hz to 24 kHz within 3 dB and bass extension of 35 Hz at 6 dB down. Sensitivity reaches 90 dB at 2.0 V and 1 m, and maximum output is given as 110 dB. Nominal impedance is 4 ohm with 8 ohm compatibility and a minimum of 3.4 ohm. The recommended amplifier power spans 25 W to 150 W. The bass reflex cabinet is 1,075 mm high, 240 mm wide and 350 mm deep plus 12 mm, and each speaker weighs 24.6 kg.

Engineering and use context

All three cone drivers belong to the DiaDrive family, in which a smoothly dished aluminium matrix diaphragm is joined to an inverted surround and backed by a vented subcone. Venting the cone is meant to reduce resonance in the midrange, and a vented cover sits over the surround. The Ring Dome treble unit keeps the middle of its dome fixed and the voice coil attaches partway across it, forming two rings that the coil can drive more accurately, and Mission states usable output up to 30 kHz. The curved cabinet uses special internal bracing that locates and supports the driver magnets, carries dedicated damping material, and vents through slot-shaped reflex ports at the rear with serrated flares. Inverted Driver Geometry places the drivers so that the acoustic path lengths to the listener are evened out.

Pairing

The high sensitivity makes the ZX-4 relatively easy to drive at normal levels from a modest integrated amplifier, though its impedance dip asks for an amplifier stable into low loads, and choosing one near Mission's maximum power recommendation leaves margin for peaks. For multichannel use the ZX centre and surround models complete a system built around a pair.

Alternatives

The Mission ZX-5 is the costlier three-way tower in the same series, fitting 165 mm DiaDrive bass units and priced at GBP 1,599 per pair at launch.