Project #2 - Documentation for Speaker as a Microphone

Upon the advice of a general aviation pilot I know, I went to the southwest side of the Austin Bergstrom International Airport. I decided that I should inform the airport police as to why I would have a truck backed up to a fence with a funny-looking box and a black pointy-looking object aimed at the runway while I was standing there wearing wires and earmuffs. A wise choice since they told me of an observation point about 150 yards from the east runway. They also wanted my name, UT ID, truck license number and description. It was a good recording site where I had to wait for a man to finish mowing the grass with a tractor.

There was a wide variety of aircraft traffic on this runway, from general aviation single-engine props to commercial jets and, the best treat of all, a couple of military F16s from the Texas Air National Guard.

I recorded the right channel using the 15-inch speaker as a microphone by simply plugging it into the right channel. If I do this again, I will put a 20db attenuator in line with it. Its output level was impressive, causing the input preamplifier of the Tascam DA-P1 DAT recorder to clip at times. The left channel input came from a Sennheiser MD421 dynamic microphone. Amplitudes reached 110db during the F16 take-off.

*NOTE: Use CAUTION when playing the audio from these clips. Small speakers will not produce the low frequencies on the right channel. You may cause harm to your speakers and your ears at high amplitudes. Use at your own risk.