
TheWall of Sound was an enormoussound reinforcement system designed in 1973 specifically for theGrateful Dead's live performances. The largest concert sound system built at that time,[1][2] the Wall of Sound fulfilled lead designerOwsley "Bear" Stanley's desire for adistortion-free sound system that could also serve as its ownmonitoring system. Due to its size, weight and resulting expense, the full WoS was only used from March to October of 1974.

Stanley andDan Healy and Mark Raizene of the Grateful Dead's sound crew, in collaboration with Ron Wickersham,Rick Turner, and John Curl ofAlembic designed the sound reinforcement system in an effort to deliver high-quality sound to attendees of Grateful Dead concerts, which were drawing crowds of 100,000 or more at the time. The Wall of Sound combined six independent sound systems using eleven separate channels. Vocals, lead guitar, rhythm guitar, and piano each had their own channel and set of speakers.Phil Lesh's bass was piped through aquadraphonic 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 ofintermodulation distortion.[2]
Several setups have been reported for The Wall of Sound:
This system projected high-quality playback at six hundred feet (180 m) with an acceptable sound projected for one-quarter mile (400 m), at which point wind interference degraded it. Although it was not called a line array at the time, the Wall of Sound was the first large-scaleline array used in modern sound reinforcement systems.[6] The Wall of Sound was perhaps the second-largest non-permanent sound system ever built.
There were multiple sets of staging and scaffolding that toured with the Grateful Dead. In order to accommodate the time needed to set up and tear down the system, the band would perform with one set while another would "leapfrog" to the next show. According to band historian Dennis McNally, there were two sets of scaffolding.[7] According to Stanley, there were three sets.[8] Four semi-trailers and 21 crew members were required to haul and set up the 75-ton Wall.
The Wall of Sound is the name some people gave to a super powerful, extremely accurate PA system that I designed and supervised the building of in 1973 for the Grateful Dead. It was a massive wall of speaker arrays set behind the musicians, which they themselves controlled without a front of house mixer. It did not need any delay towers to reach a distance of half a mile [800 m] from the stage without degradation.
Though the initial framework and a rudimentary form of the system was unveiled atStanford University'sMaples Pavilion on February 9, 1973 (everytweeter blew as the band began their first number), the Grateful Dead did not begin to tour with the full system until a year later. The completed Wall of Sound made its touring debut on March 23, 1974, at theCow Palace inDaly City, California.[2] A recording of the performance was released in 2002 asDick's Picks Volume 24.
The Wall of Sound acted as its ownmonitoring system, and it was therefore assembled behind the band so the members could hear exactly what their audience was hearing. Because of this, Stanley and Alembic designed a special microphone system to preventfeedback. This placed matched pairs ofcondenser microphones spaced 60 mm apart and wired in reverse polarity from each other. The vocalist sang into the top microphone, and the lower mic picked up whatever other sound was present in the stage environment. The signals were added together using a differential summing amp so that the sound common to both mics (the sound from the Wall) was canceled, and only the vocals were amplified.[10]
The Wall was very efficient for its day, but suffered from multiple drawbacks in addition to its sheer size. Frequent guest keyboardistNed Lagin (best known for performing experimental interludes with various permutations of Lesh,Jerry Garcia and drummerBill Kreutzmann throughout 1974 set breaks) preferred to play through the powerful vocal subsystem (considered to be the best part of the system); however, the group's sound crew often neglected to switch between his quadrophonic input and the vocal input during long sequences, resulting in few of his contributions being recorded.[11] Additionally, as many as two channels of his input would still be lost in the mix when the system was working properly.[11] The Wall's quadraphonic format did not translate well tosoundboard tapes made during the period, as the sound was compressed into an unnaturalstereo format and suffered from a pronounced tinniness.
The rising cost of fuel and personnel, as well as friction among many of the newer crew members and associated hangers-on, contributed to the band's "retirement" after the 16 to 20 October 1974 shows in San Francisco'sWinterland Ballroom. A selection of these final performances can be seen inThe Grateful Dead Movie.
The Wall of Sound was disassembled, and when the Dead began touring again in 1976, it was replaced with a more logistically practical sound system.
On 14 October 2021 during aSotheby's auction called "From the Vault: Property from the Grateful Dead and Friends"[12] several portions of the Wall sold including a portion of the center vocal cluster and a handmadeAlembic speaker cabinet for $17,640. Also sold were multipleMcIntosh MC-2300 amplifiers, one sold for $94,500.
The WoS was used during these 1974 recordings:
The Wall of Sound required two stages, which leapfrogged each other, alternating shows, so that as one was being set up, the other was traveling to the next show.