Напольная акустика — Mission QX-3 MKII

The QX-3 MKII is the entry floorstander of the QX MKII series by Mission, the British loudspeaker maker in the IAG group. The range reached the market in September 2021, and at launch this model cost GBP 799 per pair, below the QX-4 MKII and the three-way QX-5 MKII. Mission presents the MKII generation as a step by step refinement of the QX design, guided by listening sessions under acoustic director Peter Comeau and by laser interferometry, computer-aided optimisation and crossover modelling.

Key specs that matter

This two-way bass reflex tower uses a pair of 135 mm long fibre composite cones and one 38 mm textile ring dome tweeter, which comes in at 2.0 kHz. Mission quotes 42 Hz to 24 kHz within 3 dB and 36 Hz at the -6 dB point. Sensitivity is 88 dB referenced to 2.0 V at 1 m, and the peak SPL figure is 95 dB. Impedance is 4 ohm nominal, which Mission describes as 8 ohm compatible, with a lowest value of 3.8 ohm. The ported box has a volume of 35 litres and measures 950 mm tall plus a 20 mm plinth, 195 mm across and 300 mm deep plus 10 mm at the terminals. Net weight is 20 kg per speaker, and buyers can pick walnut veneer, Black Oak or Matte White.

Engineering and use context

In the QX floorstanders the ring dome tweeter is mounted between the two woofers in a D'Appolito array, an extension of Mission's Inverted Driver Geometry that equalises path lengths and improves time alignment at the listening position. Each DiaDrive woofer is a single curved diaphragm without a seam or a dust cap, stiffened by acrylic fibre in its composite mix. On the tweeter the textile dome is anchored in the centre and driven through a voice coil fixed part way along it, giving a double ring shape, and a phase plug stops treble waves cancelling across the middle of the dome. A twin cavity behind it is non-reflecting. Serrated surrounds shaped with air-flow analysis reduce edge reflections, and the slot port is flared with serrations to calm air movement. Aluminium plates on the top and bottom, colour matched to the finish, add weight and rigidity.

Pairing

Mission suggests 25 to 120 W of amplifier power. With its low impedance minimum, a solid-state amplifier that handles such loads without strain is a better match than a low-output valve design.

Alternatives

The QX-4 MKII is the bigger two-way tower in the same line, with two 165 mm woofers, a 48 litre cabinet and deeper bass extension.