Thursday, April 20, 2017
(from last time in case needed)
This code plots the spectrum of a sound in a wav file: plot_spectrum.py
Example wav files: guitar low E, piano low F, brass bar
Here is the spectrum of the brass bar:
And here is the spectrum of the low piano note:
(Notice that the "fundamental" (the lowest frequency) is almost not present.)
Online tone generator in case it's useful
This code produces a sound with components we specify: replicate_sound.py
Let us see if we can synthesize the recorded brass bar sound above using frequencies and amplitudes read from the spectrum of the recording:
Let's record the sound a drum, and analyze and synthesize it.
[In case of difficulties, I prepared these in advance: small tom closed, small tom open]
Let's solve this problem by separation of variables, find the spectrum, and see if it matches the recording of the real drum.
Relationship between F and f:
Code that made the picture above: circular_membrane_modes.py
# enter frequency components here freqs = 120.*array([1,1.593,2.136,2.295,2.653,2.917]) amps = array([1.,1,1,1,1,1])
synthesized_drum.wav (first effort, just guessing frequency of fundamental)