Physical System
The physical set up of equipment is quite simple. The system itself consist of the 4 microphones composing the array, the D.A.Q device, and a speaker amplifier pair to generate the sound source. Obviously the computer running the system should be included in this list.
Equipment List
- Koss M-18 electret microphone
- the National Instruments NI USB-6210
- Signal Conditioning Board
- Standard Stereo Amplifier
- Generic Speaker
- PC running MATLAB
Sensors
The sensors used as mentioned above are the Koss M-18 electret microphone. The microphones were cut away from the stands to make them smaller and more simple to adjust. These microphones are omnidirectional and have a frequency response of 100 Hz to over 20 kHz. They use a 3.5mm, 3-contact plug which is meant to connect to a computer sound card. Additionally, a signal conditioning board was built to provide the microphones with the proper interface to the D.A.Q as well as adding a simple DC blocking filter to remove the extremely low noise present on the line. These are shown below
