Benefits at lower frequencies always bring a dividend further up the range. The performance steps away from the speakers – turn out the lights and the, despite their size, the speakers can disappear completely with most recordings. Instrumental tonality is more distinct, developed and natural, enunciation and diction are better, lines and phrasing, vocal and instrumental, clearer, more articulate and more expressive. Focus, air and transparency at high frequencies improves, while musical coherence is better across the range. Ticking cymbals or brushwork are more precise and integrated, insistent where they should be, relaxed when necessary. That temporal integrity is a huge step forward in terms of the presence and intent of the performers, the improved dimensionality, colour and sense of space all helping to bolster the illusion of real people in a real space. Play your stereo spectaculars and they will be, well – spectacular. But it’s the core musical integrity in recordings that is the real winner here. Everything hangs together more naturally and clearly, revealing its flow and pattern, its shape and purpose. The X-base takes what was already a seriously impressive, engaging and rewarding speaker and improves it across the board. I always described the U2 as a “big A5”, which was a massive musical complement. Now the resemblance stretches beyond the musical similarities to its position in the market place. The A5 might just be the best pound-for-pound box speaker in its price range. On the basis of this relatively brief listen (and alongside the Rockport Lyra) , the U2-X can make a serious claim to similar status.
The musical benefits of the X-base are startlingly obvious. I was genuinely shocked by their magnitude. This was not what I was expecting at all! I thought that the X-base would improve handling and as a result, improve performance, but this goes way, way beyond that. I can only surmise that their impact is operating on two levels, the whole being greater than the sum of the parts. In mechanical terms, I’m sure that the X-base is providing superior termination and grounding to the cabinet. A major part of that is their two-part structure. Cut an X-shape out of billet aluminium, hang it up and hit it with a hammer: it’s going to ring like a bell. Now do the same thing with a two-part construction, with a massive and securely bolted overlap and all you’ll hear is a dull “thunk”. The combination of massive weight and self-damping has to dissipate energy from the speaker enclosure more effectively than the original cones, while the huge surface area of the 48mm threads (that’s almost 2”!) will sink that energy more readily into the posts and ground. So it’s no surprise that the X-base cleans up the U2’s bottom end.
Settling in…
But the second part of the equation is equally important. The accessibility of the threaded posts and the inherent resistance of the huge threads make really small, repeatable adjustments incredibly easy to dial in. Towards the end of the set up process, I was making adjustments in angle or overall speaker height involving rotational movements of a little over a millimetre (or three degrees) at the outer circumference of the adjustment knobs. Relate that to the pitch of the thread and you are raising or lowering the post by around 0.025 of a millimetre – with clearly audible affects. The ability to adjust this finely is priceless – at least if you want to realize the full performance potential of your expensive audio system. It’s also next to impossible with most speakers on the market. Anybody who doubts just how critical and exacting speaker set up is to system performance needs to spend a few minutes with the U2-X: that really is all it should take…
