What it actually decides.
Coordination is the planning step that assigns each microphone, in-ear and comms channel a frequency that is clear locally and compatible with every other channel in use. It is done with scanning hardware and coordination software, before the show, and repeated when the environment changes.
The reason it cannot be done by spacing channels evenly is intermodulation. When two transmitters share the air, their signals mix in the receiver front end and create new signals at predictable frequencies — for carriers at f1 and f2, the strongest unwanted products land at twice one minus the other. Those products fall outside the span of the two channels that produced them, so they can land directly on a third microphone that looked perfectly clear on its own. Every transmitter added multiplies the combinations rather than adding one, which is why the practical ceiling in a six megahertz television channel is around seventeen narrowband channels rather than the thirty the arithmetic suggests.
The site matters as much as the maths. A scan has to be taken in the actual room, because a building’s shielding changes which broadcasters are audible inside it.
In Miami there is a local trap worth knowing: the lowest television channel in the band is shared with land mobile radio, including public safety, and that service has priority. A frequency that scans clean there is still the wrong one to use.
We own this equipment.
Event audio production — owned inventory, our own crew, and a site survey before anything is specified.