Напольная акустика — Mission QX-4 MKII

The QX-4 MKII sits above the QX-3 MKII as the taller tower of the second-generation QX series from British brand Mission, a mid-level range of seven models pitched as a step up from entry-level speaker lines. It is a passive two-way tower with a pair of 165 mm bass units and one ring dome treble unit. The UK launch price was GBP 899 per pair, and at launch the whole series became available from September in matte Lux Black or Lux White or in walnut wood veneer, while the current finishes are Black Oak, Matte White and Walnut Pearl.

Key specs that matter

Both 6.5 inch woofers use long fibre composite cones, and the 38 mm treble unit is a textile ring dome, with the handover set at 2.2 kHz. Mission rates the frequency response at 36 Hz to 24 kHz within 3 dB and gives a bass extension of 32 Hz at the 6 dB point. Sensitivity is 88 dB measured at 2.0 V and 1 m, and peak output is listed as 95 dB. Nominal impedance is 4 ohm, described as 8 ohm compatible, with a minimum of 3.8 ohm. The suggested amplifier range runs from 25 W to 150 W. The bass reflex cabinet holds 48 litres and stands 980 mm tall plus a 20 mm plinth, with a width of 220 mm and a depth of 335 mm plus 10 mm for the terminals. Each unit weighs 23.8 kg net.

Engineering and use context

Mission uses what it calls Inverted Driver Geometry, placing the treble unit below the bass and midrange drivers so that the distances travelled by the output of each unit to the ear come out closer to equal, which helps time alignment. The ring dome has a fixed centre carrying a visible phase plug, a layout intended to stop cancellation across the centre axis of the diaphragm at high frequencies and so extend treble output with lower distortion than a conventional dome. The bass cones are made from an acrylic fibre composite, and the driver surrounds have a serrated edge shaped with the help of airflow analysis to scatter reflections and reduce air turbulence around the cone. A colour-matched aluminium plate on top of the cabinet is there for more than looks, since it adds rigidity to the enclosure.

Pairing

With its low impedance minimum, the QX-4 MKII needs solid-state amplification or an AV receiver comfortable with low impedance, and its average sensitivity means an amplifier near the top of the recommended range leaves more headroom than one near the bottom. The QX MKII family also includes bookshelf, centre and subwoofer models, including the QX-12SUB MKII, for building a surround system around a pair of these towers.

Alternatives

The Mission QX-3 MKII is the compact QX MKII tower, using two 135 mm bass units in a 35 litre cabinet with a lower recommended amplifier power.