Active listening to the entirety of Exai (as in "eleven") is, of course, an endurance test, as it is 120 minutes in length and consists of 17 tracks that could be sequenced in any order with no change of effect. Processing the whole thing is less daunting than it seems on the surface. It begins with the hyper-speed scramble-clutter of "Fleure," but beneath that, there is a bounty of tracks that are riveting and accessible, if by Autechre's challenging and meticulously crafted standard. Several standouts, once fully absorbed, sound utterly unique. "Bladelores," one of three captivating tracks that lasts over ten minutes, has a probing skank to it with a nearly piercing acid line over a buried and blurred symphony. The energizing and abnormally uplifting "T ess xi," led by a direct synthesizer melody and crunching drums, could pass as a remix of something from West London's broken beat massive. "Recks On," somehow crisp and sludgy, is a peculiar hybrid of big beat and bass and is one of the heaviest pieces the duo has produced. The album could have been pared down a bit, yet it's a drop in a bucket for Booth and Brown. Prior to this, their discography clocked in at 18 hours or so. What's another two hours?