UK producer Duct returns with “Span,” a heavy workout submerged deep in the shadowy underbelly of bass. Loosely coinciding with the release of the Bell Tower EP—his collaborative effort alongside Owen Howells, out this week on his own Shades imprint—it’s a crackling and jerky cut that teases out the tension for the first minute with ghostly wails and a procession of false starts. The action strikes in the second minute when a lo-fi sampled break hits a nostalgic note, evoking an aggressive frenzy of old-school jungle rhythms, complete with a wild-pitched snare drum that detunes as it pops like stray machine gun fire. Duct’s “Span” production can be downloaded below, and a preview stream of his and Howells’ recent collaborative EP can be heard after the jump.