Karel describes the first track, an excerpt from his current Materials Recovery Facility project: "It's made with location recordings from the Casella Waste Systems facility in Charlestown, MA, USA. This is where commingled (‘single stream’) recyclables collected by various surrounding municipalities and institutions are brought for sorting. The facility uses massive overlapping conveyor belts and automated sorting methods including optical sensors, precisely directed blasts of compressed air and magnets. But the machines don’t function nearly as effectively as expected so a large staff of human workers manages much of the separation by hand. Originally recorded in quadraphonic audio, this is the stereo version."

The last two tracks "Oberterzen-Unterterzen" and "Dallenwil-Wiesenberg" are excerpts from Karel's Swiss Mountain Transport Systems album, reviewed by Abi Bliss in The Wire 333 and out on Gruenrekorder. Alongside his location recording activities, Karel is a lab manager at Harvard University's Sensory Ethnography Lab.