How Pink Floyd's Quadraphonic PA and Custom Lighting Rig Rewrote the Concert Experience

Most people know Pink Floyd for Dark Side of the Moon and the prism, but the reason that album sounded so huge in concert was because the band spent the early ’70s essentially inventing modern arena sound and lighting from scratch. They weren’t just another band with a light show — they were the band that figured out how to make a quadraphonic PA system actually work in a live setting.

The linchpin was the Azimuth Co-ordinator, a custom joystick-controlled panning device built in 1970 that let the mix literally spin around the audience. Combined with a four-channel PA system (at a time when most venues were still mono), the band could throw a helicopter sound from the back of the hall to the front mid-song. On the Dark Side of the Moon tour they added a circular projection screen that doubled as a lens for a custom-built light show, using 16 mm film loops, strobes, and fat beams of light from modified aircraft landing lamps. The entire rig was run by a road crew who had to synchronize tape machines, the Azimuth, and the lighting console by hand — no computers.

That same touring system also introduced the first practical use of a PA as an equalized, multi-speaker array for a rock band. Pink Floyd’s sound engineer Alan Parsons (later of The Alan Parsons Project) worked with the band to tune the system so that quadraphonic effects were precise even in dodgy halls. It wasn’t just a gimmick; it changed how live sound was mixed. If you’ve ever stood in a stadium and heard sound move from one end to the other, you can thank the early ’70s road crew who soldered those first Azimuth boxes together in a London basement.