The self-powered Yamaha YSP-1100 is a DSP-controlled, 42-driver (40 ?beam drivers? plus two woofers) speaker array that produces digitally synthesized ?beams? of sound that can be angled to create wall reflections, which simulate the output of conventional five-channel surround speaker systems. It comes close to sounding like a real 5.1-channel surround speaker system and also serves as a full-featured A/V amplifier.