With more than two thousand seats, UC Berkeley's Zellerbach Hall hosts big orchestras, tiny quartets, stage choruses, and laptop rockers. So how do you adjust the physical acoustics of the building to benefit each show? You can't, but technology can. Cal Performances installed a new sound system this year with the help of Berkeley-based hi-fi manufacturer Meyer Sound, whose top techs measured the acoustics and deployed their new Constellation system. Microphones, speakers, and digital signal-processing equipment were networked to create a unique "variable room acoustic system." That's nerd-talk for a PA that adapts to plays, concerts, lectures, or cinemas at the flick of a button. It boosts musicians' ability to hear each other and brightens low-projection instruments like French horns and string basses. Multichannel reverb and early reflections? Generated. Mixing, processing, and routing on the fly? Done. Pitch-shifting and other annoyances? A thing of the past. Plays like King Arthur at Zellerbach? A state-of-the-art experience.