Much like their monthly sets at New York mega-club Twilo, and last year's Northern Exposure: Expeditions set, Alexander "Sasha" Coe and John Digweed's new Communicate mix is a musical marathon. Together, its two CDs present more than two hours of progressive house and trance, offering enough beats to tire even the most athletic of supporters under unmedicated circumstances. And like all but the finest long-distance runners, Communicate's energy level lags in places, trying to make up in quantity for what it lacks in consistent quality.

The first disc especially is a long-winded bore, made up of 11 dry, hookless trance tracks that seem to gaze into their own finely-EQ'd navels for minutes on end, taking the listener absolutely nowhere.

Fortunately, disc two is far trippier — and thus far better. Instantly staking out an acidic deep-house territory with Mainline's "Narcotic" (RealAudio excerpt), Sasha & Digweed hop through mostly obscure current records is at times as glorious as their legendary all-night excursions can be. Standouts? Killer Loop's "The Blue Hour" (RealAudio excerpt) blurs the line between trance and teched-up house with a bassline to die for, while King of Spin's "Lifestyles — Part 2" (RealAudio excerpt) is like a dosed mega-mix of cuts from the Chemicals Brothers' Surrender.

If this sort of genre-blinding sonic communiqué is what Sasha & Digweed are trying to relay with their sets, then Communicate is a half-truth.