XO Wave: Dither in XO Wave (Technical Note)

Important Notice: XO Wave is now discontinued as we prepare to bring you the next generation Digital Audio Workstation called Xonami. This site remains available for anyone who purchased XO Wave in the past. However, please keep in mind that as discontinued software:

This site may not contain up-to-date information.
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This page describes how dither is managed in XO Wave. For more info on dithering in general, see our article A Bit about Dither. You may also want to see our technical note on Resolution in XO Wave.

Default Dither Type: XO Wave uses a high-quality, noise-shaped triangular dither by default. This dither is less audible than plain "white" noise, because its energy is distributed primarily in frequencies that our ears are less sensitive to.

Custom Dithering: Dither can also be added manually by using the Dither/Noise effect. Combining the Dither/Noise effect with other filters on a dedicated track enables the creation of dither fine-grained control.

When Dither Is Used by Default: By default, dither is applied when outputting 16-bit and 8-bit AIFF and WAV files. It is not applied when creating QuickTime files because the QuickTime software does bit-depth reduction, and so it is usually not appropriate to add dither before passing audio to QuickTime. It is also not applied to 24 and 32-bit files because it is not needed at high resolutions. Dither is not applied to recorded audio, because the audio resolution provided to XO Wave usually matches the resolution of your sound device.

When Manual Adjustments Are Needed: When exporting files and creating CD Masters, it is rarely necessary to alter the default dither settings. For playback, however, the default is not always adequate because XO Wave may not be able to detect the resolution of your sound device, and because XO Wave's output may be manipulated by the operating system or device drivers. For example, XO Wave's output may be sample-rate converted, combined with output from another source, or have its overall level altered before its resolution is reduced. This may be the case in Mac OS X, and on Linux when using the ALSA and Jack interfaces.

Because XO Wave cannot know what will later be done to the audio it produces, it can be useful to manually modify the output dither settings in the Hardware Settings window. By default, XO Wave adds dither appropriate for 16-bit output. If your audio hardware is 16-bit, this is generally correct, although the results may not be optimal if the device is shared with other software or sample rate conversion is being performed. If your audio hardware supports a higher resolution, you may want to simply turn dithering off, since dither is rarely needed for resolutions above 16 bits. You will want to use the 8-bit setting when your hardware is 8-bit, or you are planning to output 8-bit files and wish to hear how they will sound. You may also wish to turn off dithering if absolutely no processing is taking place and you wish to maintain bit transparency.