Longer threads on the supplied cones were an interim solution that at least allowed for a greater degree of adjustment, but the real answer lay in a larger footprint and easier adjustment, mandating some form of outriggers or plinth. Everyone who worked with the speakers, from reviewers to dealers and distributors agreed on the requirement – but no one was quite ready for the solution that ultimately appeared.
First used in Munich this year, the X-base consists of a massive aluminium cruciform structure supporting four large diameter threaded posts. In fact, “massive” really doesn’t do the X-base justice. You need to actually handle this thing to appreciate how big, how heavy and how beautifully put together it is. Which is just as well as a pair of X-bases will set existing U2 owners back the wince-inducing sum of $25,800! Or – as much as a very nice set of floor-standers from many a loudspeaker brand. The sticker shock wasn’t exactly ameliorated by the fact that the sound in Munich was distinctly sub-par. Who, one wondered, was kidding who? So I was understandably interesting in discovering just why the X-bases are so expensive – and whether they can possibly justify that price.
Although I’m going to be concentrating entirely on the X-base here, it actually constitutes one part of a complete U2 revision, a series upgrade that includes new jumpers for the level adjustments, revised cable routing and a few other internal niceties. Taken together, those changes add up to a new model, the U2-X, which will replace the existing U2. Owners of existing speakers will be able to add the X-base and jumpers for the difference in price between the two models – which is where that $25,800 price tag comes from.
Of the two, it’s the X-base that is both visually and sonically more important, so let’s start by looking in detail at its construction.
Each X-base consists of two over-lapping halves, machined from solid aluminium plate 55mm thick. As well as carving out the cruciform ‘legs’ the underside is profiled to create space for the casters that the X-base accommodates and to ensure an intimate mechanical embrace between the front and rear sections. The end of each leg is rebated from beneath to take a threaded brass collar. The M48 (yes, you read that right) posts are machined from INOX stainless-steel and topped off large diameter aluminium knobs. The set I got to play with were prototypes with roughened surfaces, but in production, those knobs will have a knurled pattern to aid grip and an indication on the top surface to show angular adjustment. They were also extremely long. Stenheim will offer the posts in two lengths: the ones that you see in the pictures (for extreme situations) and a 3cm shorter ‘standard’ version for normal use. The bottom of each post tapers slightly to 40mm diameter and is then tipped with an integral M10 threaded post that accepts a range of different ‘tips’ to aid set up and provide the optimum interface with different surfaces/floors. The two ‘standard’ INOX tips are a shallow cone (for general use) and a longer, sharper ‘spike’ with a concave profile (for piercing carpets). You also get a set of domed tips machined from POM-C engineering polymer (to allow easy movement of the speaker and protection of the floor when looking for your initial position) and a 90mm diameter INOX footer to use with the dome or cone tips if the floor needs protecting. Stenheim are also considering supplying the domes in INOX, for use on hard floor surfaces such as tiles or marble. Interestingly, the footer adds 9mm to the height of the speaker, while each post rotation adds (or subtracts) exactly 3mm, so it is easy to set up with or without the footer and switch later.
