Dither can be explained very easily, but yet, it is a very misunderstood term in the world of audio production. How can something so simple be so complicated and hard to figure out? I asked this question because i see experienced professional audio engineers asking the same questions over and over.
I hear them ask:
"When do you dither?"
"Why do you dither?"
"is dither needed when going from 32bit float to 24bit fixed point?"
What Is Dither
Dither adds random low level noise to your audio files to lower the risk of errors that can happen when you convert the bit depth from higher to lower depths. Dither should be done at the very last step and it is done in the mastering stage. The mix should only go through the dithering process one time to keep its integrity. So if you are mixing in 32bit floating point inside your DAW, do not convert your audio files down. When you export them for mastering, export it as a 32bit floating point file. Dither is used for video data in almost the same way it is used for audio files.
The True Definition Of Dither - Dither means to tremble, quiver and shiver. It is also an act of being nervous and agitated.
When To Dither
Here are some scenarios for dithering, if you 'should' or 'should not' dither
You are importing your 24bit audio file into your DAW that converts everything imported to 32bit floating point, should you dither? NO! becasue you are going up in bit depth.
You're bouncing or exporting an audio file from 32bit floating point to 24bit, should you dither? YES! Becasue you are lowering the bit dep You are lowering the bit depth.
You are converting a 24bit audio file to a 16bit audio file, should you dither? YES! Becaasue you're going down in bit depth.
Maybe you want to save your PC's resources and bounce some audio tracks so they have all the plugin effects printed to them, should you dither? NO! Make sure your bounce settings in the DAW are set to the same bit dep Make sure your bounce settings in the DAW are set to the same bit depth.
You have 16bit audio files you want to import into your DAW and your DAW import properties are set to import all audio to 32bit floating point, should the import properties be set to dither? NO! Becasue you are going up in bit depth.
Conclusions Of Dithering
After reading this, can you think of a situation when you find it hard to decide if you should dither or not? Just remember that if you are going from a higher to lower bit depth, you dither. You only dither once and that is in the audio mastering stage. So never convert to lower bit depths when you are mixing. Keep them the same when bouncing, exporting and processing your audio files.