Supposedly, you can attach these to any surface & change it into a speaker/transducer. You could stretch a piece of heavy duty Reynolds Wrap in a frame, stick one of these things on, and presto – flat panel speaker.
Dayton Audio DAEX25 Sound Exciters turn virtually any solid object into a speaker by vibrating it at speeds of up to 20,000 cycles per second. The vibrations modulate the air, which is then decoded by the brain as sound. We've tested and placed Sound Exciters on nearly everything you can imagine; under a desk, in an overhead cabinet, behind picture frames, inside cans, behind paper plates, inside binders, cardboard, scraps of wood and even the box they came in! Test the limits of your imagination. Each stick on Sound Exciter is designed using patented nxt® transducer technology for a wide frequency response and great sensitivity. Built-in push terminals enable quick connection to the included pre-stripped speaker wire. Strong 3M adhesive pads affix to nearly any solid surface for secure, long-lasting playback. Package includes two Dayton Audio Sound Exciters and two pairs of 5 ft. speaker wire. Specifications: • Power handling: 6W RMS • Impedance: 8 ohms • VCdia: 1" • Dimensions: 3-1/2" dia. x 3/4".
• Turn any solid surface into a great sounding speaker system
• Create a completely hidden surround sound system
• 3M adhesive pads for secure and fast placement
• Wideband frequency response (dependent on attached material)
It would be cool to rig something up & plug it into the Emotiva XPA-2 just to watch it catch fire.