When to Use a Dither Plug-In
You should use a dither plug-in in any situation where you are reducing bit depth, for example, when mixing down to a 16-bit file with the Export Audio Mix command, or when sending your final mix to an external digital device that records at 16-bit resolution.
Since Pro Tools | First project audio files are 32-bit float, it necessary to a dither plug-in when exporting audio. Pro Tools | First uses 24-bit audio input and output signal paths, and internal 64‑bit floating point processing for mixing and audio processing.
For this reason, the following are recommended:
• When exporting to a 16-bit or 24-bit audio file, use a dither plug-in on a Master Fader track on the output source path.
• When bus recording a submix to a track in the same project, do not use a dither plug-in on the destination track.
• When mixing down to a 16-bit destination, use a dither plug-in on a Master Fader track on the main output path.
• When mixing down to a destination with any 24-bit capable interface, do not use a dither plug-in on the main output.
• During normal recording and playback, bypass any dither plug-in on the main output.