The XQ’s Uni-Q also benefits from the new cone profile that was recently introduced with the Reference series.
This too is based on waveguide theory: the profile of the cone is shaped into a specific curve so that no interference patterns occurs between the direct wave and reflections of that wavefront off the cone.
This is done by ensuring that the expanding wavefront always remains perpendicular to the cone, so that no reflections can be created. This Uni-Q has a flared 118mm shiny plastic cone and unusually flat surround, while the tweeter uses a 19mm titanium dome.
The whole thing feels very solid, weighing a substantial 9.2kg. The curved top, base and sides all help increase the stiffness and avoid concentrating and focusing the internal standing waves. Two pairs of terminals fit directly through the enclosure and wire links are supplied.
The curved base requires special stand-coupling arrangements and two alternatives are supplied: a curved hard rubber pad can support the enclosure itself, or a tripod of hard feet may be used (albeit without lock-nuts, though these shouldn’t be necessary if the feet are screwed in tightly).
Our measurements comfortably confirm KEF’s 88dB sensitivity rating and also show a rather easier load (which only drops significantly below 6ohms above 8kHz) than the company’s claimed 3.2 ohm minimum suggests. Pair matching was adequate.
In-room far-field measurements indicate that the XQ20 is probably best kept clear of walls. Without any wall assistance the bass region is quite smooth and even, well- extended for the size of the enclosure, but also a little dry.
Close-to-wall siting tends to supply too much midbass (around the 45Hz port tuning frequency), somewhat at the expense of upper bass output. However, some of the extra bass that is supplied by close proximity to the wall might well be found preferable in order to balance out the rather strong top end.
The far-field in-room averaged response is quite smooth and also remarkably flat overall – but probably a little too flat through the treble region.
Experience across a wide range of models has shown that the ‘ideal’ (not to mention the average) response under these conditions shows some down-tilting in the presence and treble regions, whereas the XQ20 stays almost ruler-flat to the limits of audibility.