When Sean Booth and Rob Brown make music as Autechre, they rarely sit in the same room together. It’s been years since the two electronic musicians so much as lived in the same city. Instead, they wing software patches back and forth, not so much composing as iterating upon each other’s work. In this respect, they’re less like a traditional musical duo and more like a decentralized startup—although, after more than a quarter-century in operation, they’ve lasted a lot longer than most high-tech outfits.

Their workspace—their core creation, really—is something they refer to as “the system”: a labyrinthine compendium of software synthesizers, virtual machines, and digital processes that they readily admit would be indecipherable to anyone but themselves. Their actual method of making music could be boiled down to what they call “fuckery”: endlessly tinkering with the software in their respective studios until the results sound good enough to merit hitting the “record” switch. They consider themselves explorers as much as creators—spelunkers navigating deep in the recesses of their own mutant technology.

Despite the absence of physical proximity, the two show evidence of an uncommon sort of mind meld—perhaps the kind that comes from two programmers who know every line of each other’s code inside and out. They frequently finish each other’s sentences; they’re quick to autocomplete a wry quip. They’re affable, too, and that graciousness is further warmed—to American ears, anyway—by the gentle lilt of their Mancunian accents.

Their affability might come as a surprise, given the notoriously difficult nature of their work. For years, Autechre have been known for some of the most forbiddingly complex electronic music out there. Their roots are in rave, yet their sympathies—and their mind-melting approach to rhythm and timbre—lie closer to avant-garde heavyweights like Karlheinz Stockhausen.

Autechre’s latest might be their most daunting venture yet. Originally broadcast in four installments on NTS Radio back in April, NTS Sessions gathers eight hours of heavily abstracted electronic music and doubles as a mazelike tour of Booth and Brown’s archives. There are drone fugues, powdery hip-hop deconstructions, and algorithmic beats that dissolve into iridescent dust clouds; a few tracks even nod back to the bleep techno and electro breaks of their earliest records. Scattered throughout are mammoth soundscapes lasting 15 or even 20 minutes; the longest, the vaporous “All End,” runs nearly an hour.

On August 24th, NTS Sessions gets a full digital and physical release as four triple-LP sets of the individual shows and two gargantuan box sets—of eight CDs or 12 LPs—of the whole shebang. We caught up with Booth and Brown while they were prepping for a recent run of Australian shows to discuss the intricacies of composing for radio, their curious titling conventions, and why they don’t ever plan to go into the software biz.

Pitchfork: What was your approach going into the NTS Sessions?

Sean Booth: We approached the NTS thing the same way we’d approach a Peel session, really. There are versions and repeats of ideas that have occurred in earlier material. When NTS originally asked us to do it, it wasn’t going to be this: We’d done a DJ set for them and then they asked about doing a residency. At the time, I didn’t really feel like doing that, so I just said no, maybe in the future. I don’t think people really want to sit through our record collection again. I don’t buy that many records.