Here, a sine function is replaced with samples at 32 points. Unlike
quantization, the function can take any
value at those points; but the
function is flat between these samples. 32 points per cycle corresponds
to a sampling frequency of 220 × 32 = 7040 Hz (at the default playing frequency of
220 Hz). This causes
aliasing, where new, unwanted frequencies will be introduced. For example
a frequency of 220 Hz, when resampled, will have aliases at 6820 Hz
(7040-220), 7260 Hz (7040+220), 13860 Hz (7040*2-220),
and so on. These
frequencies
can be heard when the function is played (by clicking the **Sound** checkbox).

Press **Sine**
to get a clean sine wave, and play it for comparison. Press
**Resample** to resample it, multiple times to use a lower sampling
rate.

Next: Clipping

Previous: Quantization Distortion

Index

Generated Tue Sep 9 2008