Be advised: IV is a headphones essential album. Without them, it may get mistaken for remixed Tool instrumentals. In truth, Dub Trio does employ the same bullish hammer-on riffs that characterized ’90s metal bands, but they twist them up with psycho-jazz phrasing, steamroll them through glitchy oscillating frequencies and set that atop a madcap mix of Mensa drums and bass so low it shakes the netherworld. The whole affair has an auteur’s touch and the output is sometimes so strange and complicated that it’s graces are beyond comprehension. “But what does they have to do with dub?” is the ever-present question about Dub Trio. First, they can be fearlessly redundant, meditating on the simplest riff to the point of hypnosis. Secondly, their music has the pronounced production techniques that characterize the dub style: spiraling echoes, affected drums and auxiliary samples that creep into the mix. Lastly, Dub Trio’s approach to songwriting is treating the original version as a remix and that’s exactly what dub is, a remix. IV is as good as any other Dub Trio album and perhaps a little heavier than most. From the ruminating opener “En Passant” to the dub-stepped “Ends Justify the Means” to the doomsday ruckus of “Patient Zero”, IV is as diverse as it is distorted. Imagine: the best Mastodon album Lee “Scratch” Perry ever produced.