Let's put Sumac into context: Their forthcoming debut album, The Deal, was written by guitarist/vocalist Aaron Turner who led the now-defunct Isis to post-metal pioneer-hood in the early 2000s with monumental albums such as Oceanic and Panopticon, not to mention his work with Old Man Gloom, Mamiffer, Jodis, Greymachine amongst others. Turner's sizeable impact on experimental metal can also be extended to his lauded label, Hydra Head, which released numerous acclaimed albums during the time its doors were open (Hydra Head stopped releasing new albums in September 2012, although you can still purchase its back catalogue).

Backing Turner is Nick Yacyshyn, an explosive drummer from one of the hottest acts currently in hardcore – Baptists. While on session bass guitar duty is Brian Cook, a man who helped redefine hardcore during his time with the evolutionary Tacoma, Washington band Botch; creators of the peerless genre milestone We Are The Romans (1999). Cook also plays in post-metal instrumentalists Russian Circles and he was part of the electric and eccentric post-hardcore act These Arms Are Snakes, who formed when Botch broke up in 2002 and split themselves in 2009, leaving behind an excellent but extremely underrated discography. And if all that isn't enough to have you drooling hysterically as you try to wrap your head around this new union of respected musicians, Converge axe-mangler and in-demand producer Kurt Ballou handled the mastering of Sumac's first full-length (Ballou also introduced Turner to Yacyshyn). It's a hell of a role call by anyone's standards. Then add in the reputable weight of Profound Lore's backing and you can almost predict the mass praise that will be heaped upon The Deal regardless of what the music actually sounds like. However, for anyone familiar with Turner, Cook and Yacyshyn, you'll already know these musicians don't tend to make bad albums (far from it), and so Sumac's debut doesn't start a new trend: it's as good as you'd hope for from these guys.

Sonically, The Deal isn't a far cry from the explorations in heft and ambience that Old Man Gloom have recorded during their irregular bursts of creativity. There's also aspects of the industrial metal sturm und drang Isis adopted from Godflesh for 2000's Celestial, as well as the rhythmic battery of noise-rock bolstered by Yacyshyn's fill-frenzy drumming. Plus, the expressive, crushing bass playing we've come to expect from Cook's past creative endeavours – particularly his approach to adding depth and extra percussive pulse to Russian Circles' music – is in full force. But instead of sounding like a cluttered mélange of those individual styles and influences, The Deal displays a unified stance – maybe a result of Turner's unyielding vision for his new band (to write the heaviest music he has ever created) and his years of experience in conveying his ideas into all-encompassing art.

Moreover, the songwriting is cantankerous in its refusal to give the listener immediate gratification, shunning traditional song structures for a non-linear, more organic exploration of tonality, pressure and release, and devastating density. The transition from 'Spectral Gold's bleak ambient noise to the opening stop-start tension of 'Thorn In The Lion's Paw' causes knots to form in your stomach, akin to the effects of a good horror soundtrack. This sense of unease returns as 'Thorn in the Lion's Paw' resides, but what happens in between the atmospheric beginning and end is a jolting release with intelligent songcraft behind the pneumatic jackhammer of the guitars and pounding, churning drums. Here, the riffs buck and snap back and forth through numerous rhythmic changes as Turner's animalistic roar sporadically appears at timely stages – and Sumac use this kind of repetition as a blunt cudgel throughout The Deal.

So, where Isis enveloped you with layers of guitars and took you on lengthy ascensions and dramatic free-falls, Sumac are the opposite, even though they favour similar song lengths; instead, they dig a dank hole and bury you in the ground under mounds of distortion. Throughout 'Hollow King's 12-plus minutes, there's a belligerent noise-rock streak – like Unsane on a ground and pound mission – and there's also huge sludge riffs that recall former Hydra Head alumni Harvey Milk. This song collapses at its mid-point into what sounds like an improvised movement; Yacyshyn's jazzy drum solo supported by Turner's manipulation of harsh noise. So when the riffs come back in, the impact is multiplied as the trio converge to act as a battering ram on the senses, charging into a masochistic loop. The instrumentation is that suffocating and single-minded at times, especially during the intense 'Blight's End Angel' and the title track – two stubborn beasts sequenced one after the other that refuse to relent from doling out aural punishment. These draining moments are plentiful during The Deal's 52-minute run-time, which may prove an intimidating experience for the weak hearted. Sumac also have a tendency to stretch the heavier and quieter sections to the breaking point of your patience, which too may alienate those with short attention spans and little tolerance for such abuse.

But because of who is involved in this band (note: 'band' and not 'side-project'), The Deal will surely be met by a persevering audience with experience in the kind of music this trio have made individually in the past – and that's who this album is primarily aimed at outside of the band members satisfying their own creative desires. As closer 'The Radiance Of Being' (a minimal guitar track that, at times, sounds weirdly like Hendrix's version of 'The Star Spangled Banner') provides a desperate reprieve from the torturous tumult of Turner's riffs and his staccato hardcore bark, the neuroma caused by Cook's raw basslines, and Yacyshyn's shape-shifting rhythms, you are left with a moment to gather you thoughts, and you will surely arrive at the same conclusion: That by almost entirely banishing his melodic side, Turner has definitely achieved what he wanted to accomplish with Sumac's debut – he has created his heaviest album yet. And listeners can either rejoice in that fact or be damned amongst the noise.