Hi, Andy. Welcome here. We’ll be gentle! This is a good question, basically a general question. The answer of course is it depends on the DAW. Pro Tools does not have built in dither so dithering has to be done with a plugin WITHIN the daw. But I just learned from a friend that the export function (Command-Shift-K on MacOS) will apply noise shaped dither to the export if you choose a fixed point export. I don’t recommend going to 16 bit with that export in PT because there are no choices of noise shaping or no noise shaping in that export menu and there will certainly be better choices using external tools. But if you choose 24 bit export, then noise shaped 24 bit dither may not be your preference but in my professional opinion it’s harmless and potentially more beneficial than truncation. PT does not give you any choice of truncation in the export, this is the first case I’ve seen of a DAW dithering “behind the scenes” and doing something beneficial without user intervention. Since it’s ONLY on export I don’t see any harm in this algorithm. People can bitch and moan about it being noise shaped but at 24 bits, any HF noise due to the shaping is going to be inaudible. And if it’s being sent to mastering, even if the M.E. jacks it up a zillion dB it’s still very very very very likely to still be inaudible and inconsequential. And if the user doesn’t even want to chance that possibility, then they can export to 32 bit float (which will not dither it) and the M.E. better be capable of handling a 32 bit float file for mastering.
Some DAWs give you dithering choices. In Sequoia, in the preferences (which I object to from an ergonomic standpoint), you can choose no dither, dither multiple outputs or only dither the main 1/2 outputs. You can choose Pow-R 1, 2 or 3. If it’s set to the main outputs you can choose 16 bit if you wish, but again, you have to remember the ergonomics and turn that off when you are finished with the 16 bit task. Very unergonomic. It will default to 24 bit if you turn it on and you are set to communicate 24 bit to your interface. That’s where I leave it so it will 24 bit dither (I use POWR-1 in that case) all outputs to external devices, etc.
Then there are plugins: You have Good Hertz dither, PSP X-Dither, Stillwell Audio PsychoDither. Google the rest 🙂
I also recommend you get a free plugin called “Bitter” from Stillwell audio. Put in in various places in your session to examine what’s happening to the wordlength and you will soon get educated on the signal flow and calculations within your DAW.
Hope this helps. Experts on other DAWs will hopefully chime in.