Front of house was literally a HOUSE!
I kind of expected the low frequency problems. Too many speakers pointing at different directions can cause phase cancellation I thought they had figure something out to make it work, but they didn't!!. They chose to get more people in than to have good sound. It's all about the music, so if the sound is bad then what? U2 360° Tour means to me 360° of bad low end. Also hanged subs are not the best choice, low end coverage is more efficient when subs are placed on the ground.
Dave Rat (Red Hot Chili Peppers engineer) says: "Hanged vertical line arrays of subs: This solves the blasting the front row humans issue quite well, offers improved low end off to the sides and a more reasonable power alley (power alley is the term used to describe the area down the center of the venue where the low end tends to be more powerful than elsewhere). The issues are that the vertical sub line arrays create these cancellation nodes that project like spokes just to the left and right of audience center. The cancellation nodes can be quite pronounced to the point where there are areas with almost no sub right next to areas with powerful sub sound. Another drawback with flown subs is that they create a sideways power alley. By that I mean that there is a power alley effect that offers strong low end at floor level that tapers off as you increase in altitude. You see, the floor acts like a mirror to subwoofers. When you stack subs on the ground, the subs are sitting on the mirror, in effect doubling the energy radiated.
For a flat field show this is not really an issue, and can be an asset but in arenas and venues with humans up high, the reduced vertical coverage can be a significant issue.
Several years back I was doing a show where the sound vendor swore up and down that we needed to fly subs. Even after I killed the idea, I was surprised to not only find that they were flying subs when I arrived, but they went on to tell me they were going to fly twice as many. Why? Well, they went on to explain that they were having trouble getting low end into the balcony area of this huge indoor sports venue. After a bit muscle flexing and much to their dismay, I pressed the issue, made them drop all the subs and we ground stacked. I then personally walked the balcony with the head sound tech during the support act. "Better?" I asked. He was quite surprised and fully agreed that the subs to the upper sections issue was solved."
Other than this I love U2 and what they represent.
But like Brooke Fraser says: "This may be good for commerce but it does art a disservice".
Carlos
