That is loud, but loud is not that hard.
Here is a data sheet for what appears to be the main product, note the frequency response.
http://www.ultra-hyperspike.com/ima.../HyperSpike_HS-24_Acoustic_Hailing_Device.pdf
Here is a camcorder demo of the unit at a distance of 200 yards, pretty cool for its intended purpose.
http://www.youtube.com/watch?v=ZD-t2n4yPQ8
Now, what if you wanted to produce a similar level but with full range music instead of only upper voice range, we have a product that will do that except it has a 90 degree wide coverage angle for crowd use.
The JH-90 is used in football stadiums and other “large” and supplies superior sound quality in areas where multiple line arrays would have previously been required.
http://blog.mixonline.com/briefingr...ty-to-brigham-young-university-football-fans/
It may not be clear how this one works from this but it is a single point source like all our other full range systems.
What is hard to do is make a loudspeaker that sounds acceptable even after one generation, microphones do not hear like our ears.
Here is a camcorder demo of a JH-90, also outdoors and as was measured afterward was actually a distance of 700 feet.
http://www.facebook.com/video/video.php?v=1717077460850&oid=126113687424773&comments
The difference in sound is that normal speakers radiate sound in an interference pattern over much of the range.
While our ears and brain automatically “hear around” that, a microphone doesn’t.
When you don’t produce an interference pattern, the sound is different to your ears and a microphone. Here is another camcorder example of some smaller speakers doing the same thing.
I don’t know where this was or who did it but the sonic point comes across I think.
http://www.youtube.com/watch?v=A5aOg4Yp7fg
Without the interference pattern, it is also harder to hear the depth location of the speaker when in a living room, that (program depending) can produce a much more real stereo image because your ears don’t hear the physical depth location of the source anymore, just the signal.
Speaking of loud, in the old days I used to design transducers for high intensity sound. Some of these were used for Acoustic levitation (using sound to support an object without contact) and eventually flown on two shuttle flights in container less processing experiments.
The picture below is a system of six sound sources which are positioning the glowing sample being levitated. The sample is being heated by a large laser who’s output is split in two so it heats both sides of the sample. The sound sources are the things with the patch of acoustic foam on their faces and the set of six running hard can produce >175dB @ 22KHz. While that may not sound like it’s that loud, it is enough energy to instantly light a cigarette with acoustic friction or give you a burn if you place two fingers in the sound field with a gap between your fingers.
http://www.sciencemag.org/content/287/5455.cover-expansion
Here is how they work;
http://www.google.com/patents/about?id=74Q7AAAAEBAJ&dq=tom+danley
http://www.google.com/patents?id=ccovAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false
Anyway, that was fun but I have always loved sound and loudspeakers so I wouldn’t go back to that and besides all this time later, NASA is still scaling down due to the Government need to fight fires they set instead of investing in the future.
Best,
Tom Danley