The Grateful Dead's touring sound system

As well as being a wonderful band, the Grateful Dead gained quite a few geek props for their sound system - one of the largest and best ever put together for a touring act. Audiojunkies has a nice (but short) look at it from an Insider's point of view:

An Insider's Look at the Grateful Dead's Wall of Sound
I recently had the privilege of speaking with Richard Pechner about the Grateful Dead's Wall of Sound and his role in creating what is considered to be one of the largest sound systems of all time. The Wall of Sound was built exclusively for the Grateful Dead and it was used on their tours from 1974 to 1976.

AJ: What is your background in pro-audio and how did you get involved with the design and creation of the Wall of Sound?
Richard Pechner: I had no formal training in pro-audio. I learned from Dan Healy, Bear and Ron Wickersham. I had toured with the Band in the late '60's & early 70's as a roadie. As the Band became more popular we were playing in bigger venues and always having to deal with the inadequacies of house pa systems or lack of. Necessity being the mother of invention the Wall of Sound was born to serve the Band and it's desire to provide the best, consistent, mind blowing concert sound experience money and genius could buy. My carpentry background steered me into setting up and running the cabinet shop which prototyped and then manufactured all the cabinets in the Wall.

AJ: Was there any inspiration for the original idea or was it something that you guys wanted to do that was completely awe inspiring for the crowd? How long did it take to assemble and what sort of problems did you guys encounter in the assembly process at venues?
Richard Pechner: The design/build took months to complete. (I am not quite sure the exact time frame.) The problems we faced were numerous. One of the biggest issues was "stacking" the speaker columns and positioning of the center cluster. As the speaker columns grew in height the logistics of hand stacking them become dangerous. Those 15" bass cabinets of Phil's were no picnic to move around let alone lift and stack. We quickly figured out we needed a mechanical system. We wound up flying 1/2 ton electrical Coffing Winches (9 from Graingers) above each bay and employed a steel platform to raise the columns in place. We adapted 3 winches to lift the much heavier Center Cluster into place. The first time Billy saw the Center Cluster in place he refused to play under it so we had to move his drum platform stage front a bit for him. We also reinforced the Cluster once it was rotated to the proper angle. (We did this by attaching 2 winches to the back and one to the front.)

The basic specs:

Grateful Dead Wall of Sound Specs
26,400 watts of continuous power via 44 amplifiers
586 JBL loudspeakers (15", 12" and 5")
54 Electrovoice tweeters
75 tons in weight (approximately)

And picture from 1974, Vancouver, BC: Amazing technology for the time.