The Grateful Dead&rsquo;s Wall Of Sound, Vancouver, 1974 Array of 586 JBL speakers &amp; 54 Electrovoice tweeters powered by 48 MacIntosh 2300 ampsphoto by Richard Pechner

The Grateful Dead’s Wall Of Sound, Vancouver, 1974 Array of 586 JBL speakers & 54 Electrovoice tweeters powered by 48 MacIntosh 2300 ampsphoto by Richard Pechner

The Grateful Dead’s Wall Of Sound, Vancouver, 1974 Array of 586 JBL speakers