Accuracy of Audio Sampling and FFT

[jfdo]

Hi all,

I am intending to feed an audio signal of a guitar into the scope  input (through a microphone and amplifier) of Analog Discovery and then take the FFT to find the frequency components.

I would like to know what factors are affecting the accuracy of sampling an audio signal  that feed into the scope input of Analog Discovery and taking the FFT of that signal?

Thank you.

Best Regards

[D@n]

@jfdo,

Let's see ... the lowest typical guitar frequency is about 82Hz, and the next one up is 110Hz.  Figure each frequency will span (at best) two FFT bins, and that you want two FFT bins between them.  That means you'll want an FFT resolution on the order of about 7.5Hz, so you'll be doing about 20 FFT's per second of ... well, what's the highest frequency range of interest?  20kHz?  So, 5x/sec you'll be wanting to do an FFT of 16k samples?

Dan

[jfdo]

Thank you.