Also back in the early 1060s I worked for Executone Corporation of America. We installed vertical array systems in theaters and churches. the columns were arched and placed in each of the corners of the room at ceiling height, which was a dangerous job back then. No OSHA just climb up a 30-foot, wooden extension ladder and hang those speakers using concrete anchors made of lead. In the center of the ceiling we would place a monster 20-inch speaker aimed directly at the floor for those low frequency sounds. All the sound columns consisted of a half dozen 6-inch Jensen PM speakers.
The big difference today is that the speakers contained within the sound columns are tiny, often 1.5 to 2-inch speakers with diaphragms made of highly responsive, space age synthetics - not paper cones. They have a much wider frequency range and far less distortion than the paper cones of yesteryear. While there is some similarity in the sound columns insofar as overall distribution of sound, that's where it seems to end.
Graham Crosby designed speakers in the UK for many years, so maybe he can chime in here and provide more insight into this subject.
All the best,
Gary
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