- Wall of Sound (Grateful Dead)
The Wall of Sound was an enormous
public address system designed specifically for theGrateful Dead 's live performances by legendaryaudio engineer and LSD chemist Owsley "Bear" Stanley. The Wall of Sound fulfilled the band's desire for adistortion -free sound system that could also serve as its own monitoring system.Components and characteristics
Stanley, along with Dan Healy and Mark Raizene of the Grateful Dead's sound crew and 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. As Stanley described it,
"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 from the stage without degradation." [http://forum.lowcarber.org/showpost.php?p=6061756&postcount=1499]
The Wall of Sound consisted of eighty-nine 300-watt McIntosh model MC 2300 solid state and three 350-watt McIntosh model MC3500
vacuum tube amplifiers, driving the speakers with a total of 26,400 watts RMS. This system projected high quality playback at six hundred feet with acceptable sound projected for a quarter of a mile, at which point wind interference degraded it. The Wall of Sound was the largest portable sound system ever builtFact|date=February 2007 (although "portable" is a relative term.)Vocals, lead guitar, rhythm guitar, and piano each had its own channel and set of speakers.
Phil Lesh 's bass guitar was piped through aquadraphonic encoder that sent a separate signal from each of the four strings to its own channel and set of speakers. 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.Technical challenges
The Wall of Sound acted as its own monitor 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 prevent feedback. This placed matched pairs of
condenser microphone s spaced 60 mm apart and runout of phase . 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 summed, the sound that was common to both mics (the sound from the Wall) was cancelled, and only the vocals were amplified.Due to the lengthy installation time required for each venue, the Grateful Dead had two stages for the Wall of Sound. While one was being used, the other would go ahead to the next city and begin setup as soon as possible. The two stages would thus leapfrog each other throughout touring. Four semi-trailer trucks and twenty-one crew members were required to haul and set up the 75-ton Wall.
The Wall was very efficient for its day, but it suffered from other drawbacks besides its sheer size. Synthesist
Ned Lagin , who toured with the group throughout much of 1974, never received his own dedicated input into the system, and was forced to use the vocal subsystem. Because this was often switched to the vocal mics, many of Lagin's parts were lost in the mix. Also, the Wall's quadraphonic format never translated well to soundboard tapes made during the period, as the sound was compressed into an unnatural stereo format and suffered from a pronounced tinniness.Duration
Though the initial framework and a rudimentary form of the system was unveiled at
Stanford University 's Roscoe Maples Pavilion onFebruary 9 ,1973 (ominously, 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 public debut onMarch 23 ,1974 , at theCow Palace in Daly City, California. A recording of the performance was released in 2002 asDick's Picks Volume 24 .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 October 1974 "retirement." The Wall of Sound was disassembled, and when the Dead began touring again in 1976, it was with a more logistically practical sound system.
External links
* [http://www.audioheritage.org/html/history/jbl-pro/jbl-pro.htm Photograph of the Wall of Sound's JBL Professional speakers]
* [http://www.nii.net/~obie1/deadcd/wall_of_sound.htm Further information and schematic drawings]
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