uw-labview/week7 — pull request #7 by calebdmoore (2014-12-05 01:34:37+00:00)
Title: Week 7 - Caleb Moore, Chris Nee

**Questions**

1. Changing the pulse width does not affect the spectrum much. The speaker needs an AC signal to produce sound, and it is the falling edge of the pulse that triggers the acquisition. The only change is a longer experiment time due to the delay. If the pulse width is shorter than the decay time of the reverberation of the sound produced by the rising edge, the experiment may record that sound too, but this appears to be negligible in the data.

2. Changing the sample rate affects the frequencies available to the FFT. A sample rate of 1000 Hz is barely enough to see any detail, with the FFT cutting off after 500 Hz and a very messy resulting spectrum and a 100000 Hz sample rate provides a very clean spectrum all the way up to 50000 Hz. The minimum sample rate to describe the response up to 2000 Hz is 4000 Hz (the Nyquist frequency).

3. Reducing the volume of the pulse increases the relative amplitudes of the lower frequencies in the power spectrum.