With an array of handmade modular and vintage keyboard synthesizers Daryl Groetsch crafts melodic and layered compositions that evoke microscopic and interstellar landscapes inspired by nature, science fiction and the cosmos. Groetsch has been working under the Pulse Emitter monicker since 2002, composing and recording in his Portland, OR home studio. Writer David Keenan has called Pulse Emitter "the undisputed king of planetary scale synth hypnosis" and has said, "no one is making synth music that feels so organic, so rapturous and so `in tune' with the contours of outer and inner space as Groetsch." Inspiration for Crater Lake came from a spiritually moving camping trip Groetsch took to Crater Lake National Park in Oregon where he found it to be one of the most stunningly beautiful places he had ever been. At the time he was conceptualizing an album inspired by the moons of Jupiter and Saturn and noticing similarities between the features of Crater Lake and the moons caused Groetsch to create an album influenced by both the nature in front of him and the cosmos above. On Crater Lake Groetsch delivers his most intricately composed pieces yet by experimenting with melody and pattern synchronization. Groetsch's working method begins with conceptualizing each piece and then composing on paper, MIDI sequencing the tracks, synth programming, and finally recording and mixing. Album opener "Europa" was inspired by the clear blue water of Crater Lake and also relates to the icy surface of the moon Europa that is believed to have an ocean of water underneath it. The album's second track "lo" is about Crater Lake's ominous and harsh rock outcropping as well as the volcanic forces taking place underneath Crater Lake and the volcanoes covering the moon lo.