http://www.substation.co.nz/nzsndata/DUNEFX.html
Makes me want one of these FRAP mics they talk about.
dougmckechnie.blogspot wrote:
The “FRAP” or Flat Response Audio Pickup, Arnie explained, was actually two pieces of metal placed at 90 degrees to each other and housed in a 1 inch by ¼ inch Lucite rectangle, the sum of which gave an accurate, three dimensional representation of any waveform to within .005 distortion. The Lucite transducer was attached by a 3-foot cord with a mini plug to the metal box which contained the battery and circuit housing. The housing itself was a 4 by 2 by 1-inch metal container with a standard ¼ inch output jack, initially to be plugged into a guitar amplifier.