The BoseÃÂ® F1 Model 812 Flexible Array loudspeaker is the first powered portable loudspeaker that lets you control its vertical coverage pattern. Simply choose among four different settings. Whether youÃ¢ÂÂre playing at floor level, on a stage, or facing raked seats or bleachers, you can now adapt your PA to match the room. And once set, the system automatically changes the EQ to maintain optimum tonal balance for each coverage pattern. So, wherever youÃ¢ÂÂre playing, you can have the right coverage for the right room. And the F1 Subwoofer included in this package gives you extended bass for live or recorded music.