Harmonic Series and Spectrograms BY JORDAN KEARNS (W&L ‘14) & JON ERICKSON (STILL HERE )
220 Hz (A3) Why do they sound different? Instrument 1 Instrument 2Sine Wave
Waveform Piano Guitar Sine Wave
Overtones and Music Perception Overtones occur at integer multiples of the fundamental frequency when an object vibrates. The addition of these tones at regular intervals is musical to the human ear. Example: Fundamental (1 st Harmonic): 220Hz 1 st Overtone (2 nd Harmonic): 440Hz 2 nd Overtone (3 rd Harmonic): 660Hz Video produced by Brandon Pletsch Univ. of Georgia Medical School URL:
PianoGuitar Frequency Spectrum
Modes of Vibration: Standing Waves
Harmonic Motion in Guitar
Frequency Decomposition: Pure Sine Wave T = 2ms f = 1/T f = 500Hz
Frequency Decomposition: Pure Sine Wave T = 1ms f = 1/T f = 1000Hz
Composite Wave I
Composite Wave II
Waveform Piano Guitar Sine Wave
Spectrogram: Piano
Piano: Component Sine Waves Time Microphone Signal Amplitude
Piano: Component Sine Waves Composite Wave (From Previous Slide) Original Piano Wave Look how close with only three sine waves!!!
Fourier Series and Superposition
Why you should change strings A quick experiment with a spectrogram Old New