There's an article in the April 2009 issue of Premier Guitar magazine where Adrian Belew is interviewed. He talks about his L1 rig.
quote:
The third thing I use is the Bose L1 setup. In fact, I have two of them, and they are the towers you see. The technology is incredible. How they make this happen I don’t know, but I went to the Bose factory and they demonstrated it for me. It has a different kind of dispersion than anything else. If you stand in front of a guitar amp and move two feet to the right, you’ll get a slightly different sound. If you move to the back of the room, you’ll get a totally different sound. Not true with the Bose L1. It has a 360 degree dispersion, and they do truly sound about the same anywhere you are in the whole room.
You can walk up to them while you’re playing, and they don’t get louder —they’re the same as when you were 40 feet away. I use them because they’re a high-end product. I use them for their great fidelity, because I do use guitar synthesizer. I do play my guitar through a keyboard. I make loops, which the band then plays to. All those things come through the Bose L1s. It’s especially good in the looping area because the band can hear it really well. They no longer need to have so much extra monitoring or anything. They can hear it just coming out of my guitar rig.