FFT showing peaks at 0Hz?

1. Why is there a peak at 0 Hz in FFT?
2. What do peaks in FFT represent?
3. How do you increase the frequency resolution of FFT?
4. What is the frequency range of FFT?

Why is there a peak at 0 Hz in FFT?

Okay, the primary issue is that your audio signal has a negative offset. That explains the 0Hz peak.

What do peaks in FFT represent?

FFTs of complex vibrations have multiple peaks- one for each frequency present in the vibration. Low frequency peaks are shown at the left end of the graph. The left-most peak represents the fundamental. Other peaks indicate overtones.

How do you increase the frequency resolution of FFT?

The most intuitive way to increase the frequency resolution of an FFT is to increase the size while keeping the sampling frequency constant. Doing this will increase the number of frequency bins that are created, decreasing the frequency difference between each.

What is the frequency range of FFT?

The output of the generic FFT normally used in programming is 0-22khz for a 44.1 sample and 0-24khz for a 48khz input.