The Siren Board

http://www.noiseaddicts.com/2008/09/lou ... the-world/
Here is an article about Wyle Lab's WAS3000 modulated air loudspeaker.

You can visualize it as a voice coil driven diaphone. The voice coil drives a slotted cylinder aligned with stationary slots to the throat of a horn. At higher pressures of operation, such as 30 PSI, macrosonic distortion occurs, as air no longer behaves in a linear manner. A sine wave drive to the voice coil results in a sawtooth wave output from the horn. At low operating pressures around 1 PSI the output is similar to the input in that a sine wave input to the voice coil results in a sine wave output to the horn over its operating frequency range.

....Can I put it in my trunk? Would put my 15" 1200wrms sub to shame.

The WAS3000 takes gobs of air at moderate pressure in addition to an amplifier. The Army Research Lab uses a 150 HP compressor on their MOAS (mother of all speakers) battlefield simulator (see the huge horn on a long flatbed truck in my previous link). I believe it has a cutoff of 10 Hz. The high output of up to 30,000 acoustical watts, combined with the low cutoff produces the force of a moderate explosion.

Mac wrote:....Can I put it in my trunk? Would put my 15" 1200wrms sub to shame.

how much decibel produce it on 1 watt 1 metre like a normal speaker?