In the 80's Intersonics made servomotor subwoofers which were used for a number of large concert tours.
At some point I got to see several of these shows.
For Michael Jackson, I sat right behind the mix engineer (I think his name was Cubby) which was about 3 or 4 feet higher than the audience so the view was outstanding.
I have to say the show was dazzling and the sound was as good as I had heard at a live show.
Another memorable show was U-2 at the world music theater outside of Chicago. The sound company was pleased with the sub-woofers and arranged to give our company a dead center sky box.
It was this show that bowled me over and changed the path of my life in a way.
Sitting dead center in front of 74 full range cabinets per side, in a building open on the sides and back I was stunned by the sound. When Bono was talking to the audience with both the band and audience quiet, one could understand about 1 out of 5 words. When the band was playing if you knew the songs, you could sing along but the bands vocals were unintelligible.
I had heard a pair of the S-4 speakers before and it sounded good and the folks running the system were the best in the biz so why did it suck so bad when you have 74 per side and why is it that generally the larger the array of speakers the worse the intelligibility is?.
It's because a single acoustic event arrives as separate events depending on the distance to each source in each frequency range. This is why the spectrum of the sound changes as a function of distance or left to right location. The greater the number of arrivals, the less the original signal is conveyed and to me this seems like a parallel to the Modulation Transfer Function that is used to describe optical resolution. If your the mix engineer, your going to adjust it to sound the best.....where you are.
The solution i pursued for the last 20 odd years is to use a horn to radiate as if there was a single driver in time and space and in the large scale, there is much less effect vs distance and sounds much more "the same" everywhere.
In the last 17 years at my current work, it has become clear that the concert style banana array loudspeakers do not work the best in doors
Interestingly, the larger and or more curved the array is, the more energy it radiates sideways and in fact they can radiate more acoustic power side ways than forward and due to the self interference principal of operation, the maximum usable throw is usually about 150 feet or less not limited by loudness but sound quality.
If the concert loudspeakers weren't enough to destroy a good recording, then you have the "capture the live source" issue.
I was at a show where Blue's Traveler was playing ( a great band) and was hanging out at the mix desk part of the time. I was struck at sound check that with every snare hit, essentially all 24 channels VU showed big inputs. So instead of one impulse like a snare live, what the mics pick up is also a train of arrivals, all separated in time and all from a different perspective AND the same for all the instruments that were amp'd..
Live sound is hard but good sound on a very large scale is possible.
Tom