You have to look really hard for the speakers. They're usually camouflaged to look like rocks and buried deep in the hedges. They even have the sound system connected to back up generators so that it keeps going during power outages.

I've heard, but can't confirm that "the guy" broadcasts across the entire island from an undisclosed location somewhere in Kingston (St. Andrew Parish at least). Rumor has it that it's a government job; a section of the Bureau of Tourism. Investigations are still ongoing to track him down.