jsdafx – Digital Audio Effects in JavaScript

Oversampling

This script demonstrates the influence of oversampling on the power spectral density and quantization error. For a given quantization word length the noise level can be reduced with the oversampling factor. This applet allows to experiment this noise reduction effect, acoustically by modifying the oversampling and quantization factors, and visually with the spectral representation.

The following options can be set in the lower part of the user interface

• Quantizer
  • word length w leads to quantization step size Q=2⁻⁽ʷ⁻¹⁾
• Dither
  • rect dither - uniform probability density function
  • tri dither - triangular probability density function
  • high-pass dither - triangular probability density function and high-pass power spectral density
• Noise shaping
  • first-order H(z)=z⁻¹
• Up Sampling Factor
  • Factors from 4 up to 64 can be tested depending on the cpu performance of your machine.

You can choose between two predefined audio signals or your own local audio file to be processed.

Predefined music signal is licensed under CC-BY-3.0 by unfinite.