Dither

Dither is low-level, random noise that is added to a digital signal to mask the more obtrusive noise caused by quantization. Dithering should be used during the last stage of signal processing, when the bit depth is decreased.

The Dither plug-in also contains noise-shaping algorithms that hide the audible effects of the dithered signal by moving the noise into the higher range of human hearing.

Item

Description

Preset

If you do not want to configure the plug-in parameters, you can choose a preset from the Preset drop-down list.

Save Preset

Allows you to save the current settings as a preset. This preset can then be specified from the Preset drop-down list.

Delete Preset

Deletes the selected custom preset.

Quantization depth

This value determines the target bit depth of the audio. For example, if the audio is going to be rendered to a .wav file and written to a CD, you should select 16 bit to optimize the high bit depth signal flowing through the plug-in for the relatively low bit depth signal that is stored on CD.

Dither type

Choose a setting from the drop-down list if you're decreasing the file's bit depth and want to add dither noise to mask quantization noise. For example, if you want to burn a 24-bit audio file to an audio CD, dithering will produce a cleaner signal than a simple bit-depth conversion.

Rectangular

Eliminates distortion caused by conversion to a lower bit depth, but the noise level is dependent on the signal.

Triangular

Eliminates distortion caused by conversion to a lower bit depth and eliminates noise floor modulation by producing a slightly higher noise level.

Highpass Triangular

Eliminates distortion caused by conversion to a lower bit depth and eliminates noise floor modulation by producing a slightly higher noise level. Noise is shifted to higher frequencies than standard triangular dithering.

Gaussian

Does not perform as well as rectangular or triangular dithering, but may be suitable for some material.

Noise shaping

Choose a setting from the drop-down list to apply noise shaping to your signal. Noise shaping lowers the percieved noise floor of the signal by shifting most of the noise into the upper frequencies of human hearing.

Off

Does not apply noise shaping.

High-pass contour

Moves noise into high frequencies.

NOTE

The frequencies to which the noise is shifted (shaped) are close to the Nyquist frequency, so you should not apply noise shaping to files with a sample rate below 44.1 kHz. For example, a 22 kHz signal has a Nyquist frequency of 11 kHz. If you move most of the noise into that range, you are putting it into a sensitive area of human hearing and will produce a worse-sounding signal.

Equal loudness contour

Distributes noise equally into high and low frequencies.