Before we all got excited about building systems that would leverage Reed’s law we were into systems that leveraged Metcafe’s law, and before that we all wanted to buidl systems that tapped into Sarnoff’s law.  Radio with it’s one broadcaster to many listeners is the classic example of a Sarnoff law system.  Of course before radio you had public speakers.  If you want to build one of these older systems, say by starting your own mega-church, you’ll be wanting some big speakers.  Maybe if you watch this video you can make your own, save some cash for refreshments.