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vpde_lecture35 [2020/04/23 08:26] trinh |
vpde_lecture35 [2020/04/23 08:34] trinh |
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| The rest is about more fun stuff. | The rest is about more fun stuff. | ||
| - | ===== Real sounds from instruments ===== | + | ===== Pitch modification |
| - | + | ||
| - | ===== Tuning music and beats ===== | + | |
| < | < | ||
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| % sampling frequency. This is a cheap way of modifying pitch. | % sampling frequency. This is a cheap way of modifying pitch. | ||
| sound(fA, 659.3/ | sound(fA, 659.3/ | ||
| + | </ | ||
| + | |||
| + | ===== Tuning an instrument ===== | ||
| + | |||
| + | < | ||
| + | % Example of tuning | ||
| + | Fs = 2^13; T = 8; | ||
| + | t = 0:1/Fs:T; | ||
| + | |||
| + | % This is how tuning works. Play a 440Hz note with an off-tune 442Hz note | ||
| + | % signal | ||
| + | f = sin(2*pi*440*t) + sin(2*pi*442*t); | ||
| + | sound(f, Fs) | ||
| + | |||
| + | %% | ||
| + | |||
| + | % This is easy to show mathematically. When you add two sine waves together | ||
| + | % that differ very slightly in frequency, it gives a beating pattern | ||
| + | plot(t, f) | ||
| </ | </ | ||