Using PASCO's FFT Ap for Investigation 16D

[FortranMan]

I was trying to incorporate this lab into the course, but when I try using a tuning fork on the FFT/Spectrum Analyzer app I can't get a well defined frequency reading. I tried doing the same thing on an opensource FFT app and had the same issue. I am thinking most laptop microphones these days have built-in background noise cancellation, which is why the FFT app cannot detect the clean frequency of a tuning fork. Is there anyway to jail break this so the app works properly? What open market microphone would anyone recommend that comes without built in noise cancellation? Also does anyone know of an FFT app that comes with a trigger threshold function? These were useful in my lab if you were looking for a particular event, rather than having to keep the soundwave constant till the update rate can pick it up.

 

[berkeman]

but when I try using a tuning fork on the FFT/Spectrum Analyzer app I can't get a well defined frequency reading.

Sorry, what does "Investigation 16D " mean in your thread title?

 

[vela]

I was trying to incorporate this lab into the course, but when I try using a tuning fork on the FFT/Spectrum Analyzer app I can't get a well defined frequency reading. I tried doing the same thing on an opensource FFT app and had the same issue. I am thinking most laptop microphones these days have built-in background noise cancellation, which is why the FFT app cannot detect the clean frequency of a tuning fork.

I wouldn't think background noise cancellation would get rid the sound from a tuning fork but would instead get rid of white noise. Have you checked if the microphone works at all? Does the FFT display show anything if you talk into the microphone?

 

[FortranMan]

That's why I suspect there is some noise cancellation going on. The FFT jumps around when I speak into the microphone, but if I hold a constant humming tone it quickly dies out. The resolution of the FFT seems pretty bad as well, which was why I was using a tuning fork as a calibration mechanism.
It refers to the specific PASCO lab that calls for students to use an FFT.