When the uninitiated think of free improv, most likely what comes to mind is what's known in the parlance as "plink-plonk"--a prevalent aesthetic of quiet restraint that's produced some good stuff but more often validates musicians with little to say and even less means to say it. There's no danger of that happening here, though: if I had to come up with an onomatopoetic description for Big Deep (Grob), the debut album by the European trio Konk Pack, I'd have to go with something like "boom-bang." The album's liner notes include the cliched directive "play extremely loud," but even at low volume the music is visceral and abrasive. British drummer Roger Turner, one of the most underrated percussionists in improvised music, is a natural extrovert; like his Dutch peer Han Bennink he pushes toward a sort of controlled abandon, alternately driving and disrupting the proceedings with a winning sense of the absurd. His reactions to the contributions of his improv partners, both in Konk Pack and other situations, are frequently funny, but they come and go so fast that no joke lasts long enough to crystallize into shtick. German analog-synth whiz Thomas Lehn, who twiddles knobs and plugs in patches on his synthesizer like a hyperactive kid in a candy store, lacks Turner's sense of humor, but his quick interjections, lightning shoves, and shadowy smears also shift too fast to get ponderous. Tim Hodgkinson--best known for his membership in British prog groups like Henry Cow and the Work--here plays on tabletop guitar, electronics, and reeds, and it's often impossible to differentiate his textural sounds from those of his cohorts as they're happening. But his residue--decaying feedback, ghostly harmonics, and echoing scrapes--does tend to linger longest. Though the overall pace of the record is frenetic, there are moments of sanity: "Dream Behind Lick" builds to its fever pitch slowly, with Turner bowing his cymbals, Hodgkinson using his guitar as a gong, and Lehn shaping long curved tones. But even when the music's at its most chaotic, the volume and density are never just camouflage for a lack of ideas. Wednesday, October 3, 10 PM, Empty Bottle, 1035 N. Western; 773-276-3600.