The Grateful Dead’s “Wall of Sound” was a massive sound system designed by LSD chemist, Owsley Stanley. Jr.
The Wall of Sound fulfilled Owsley’s desire for a distortion-free sound system that could also serve as its own monitoring system.
After Stanley got out of prison in late 1972, he, Dan Healy and Mark Raizene of the Grateful Dead’s sound crew, in collaboration with Ron Wickersham, Rick Turner, and John Curl of Alembic, combined six independent sound systems using eleven separate channels, in an effort to deliver high-quality sound to audiences.
Vocals, lead guitar, rhythm guitar, and piano each had their own channel and set of speakers.
Phil Lesh’s bass was piped through a quadraphonic encoder that sent signals from each of the four strings to a separate channel and set of speakers for each string.
Another channel amplified the bass drum, and two more channels carried the snares, tom-toms, and cymbals.
Because each speaker carried just one instrument or vocalist, the sound was exceptionally clear and free of intermodulation distortion.