Speakers should be heard and not seen, but in this age of home theaters, media rooms, and whole-house audio, that's easier said than done. Custom home clients, it turns out, want their MTV and VH1—even if they come with visible grills and obtrusive black wires. Appleton, Wis.-based Acoustic Ceiling Products has inverted the old paradigm, however, with the Onsia concealed-speaker system. Each flat-panel speaker plate screws into wall studs and finishes like regular drywall. Unlike conventional speakers, which emit sound via single-band pulses from conventional cone diaphragms, Onsia generates sound through the stimulation of the entire panel surface, creating hundreds of simultaneous nonlinear vibrations that, in effect, turn an entire wall into a sound source. Acoustic Ceiling Products, 800.434.3750; www.onsiaideas.com.