I do my MIDI / preproduction work in Sonar X3 -- currently Studio version -- and am now exporting a bunch of VSTi tracks to 24 bit audio so that it can be mixed elsewhere.
 
The Studio version tops out at Triangular dither - for my purposes (basically, converting individual virtual instrument track information to audio), will there be any noticeable difference between Triangular and POWR (which is only offered in Producer)?
 
Long story, but basically I purchased/installed Studio, thought better of it, and then called Cakewalk to purchase a tack-on upgrade to Producer.  So basically I'm mid-project now running Studio X3 and would prefer NOT to install Producer until I'm finished in a few weeks...but if the lack of the POWR dither is problematic I could bite the bullet and install Producer.
 
Thanks in advance for any input/advice. -- David

Dithering should only be applied at the last stage of mastering.
If you recorded at 24 bit, no need to dithering for exported 24 bit tracks.
You would only user dithering when downsampling, eg. . . from 24 bit to 16 bit.
When you need to dither, Powr dither would be preferred over Triangular.

Thanks noynekker for the response - I'm not talking about 24 bit recorded audio however, I'm talking about rendered audio from VST instruments, which I believe are rendered internally at 32 or even 64 bits.  So I think (?) I'm still in a downsampling scenario if I'm talking about 32 bit+ VSTi information that's going down to 24.
 
But maybe I'm overthinking this?  Maybe there's not enough bit reduction occurring when going to 32 to 24 to warrant worrying about it?  
 
 
 
 

A lot depends on the type of music you're doing. If you're doing classical sessions with acoustic instruments that exhibit a lot of dynamics in a complex acoustic space, you might notice a difference. For pop music, few can tell the difference between dithered and undithered material, let alone the difference between different dithering options.
 
Furthermore, with 24-bit audio, the issue becomes pretty much moot as any rapid switching in the lowest bits will almost certainly be happening below the noise floor of any associated audio electronics. I'd be happy to stand corrected if anyone knows more details about this.

I have to say I have always found dithering one of the more ethereal bits (ha!) of music production. I use it sometimes when downmixing to 16 bits but I always have to re-google exactly which settings would be preferable for the project and why, and am often left with the idea that it doesn't really matter that much.

Perhaps then, I'm not the best person to ask, but I would also say from what I know of the process, only do it at the final stage (because you don't want to do it if you need to process the audio any further), and don't obsess about the settings overly much, unless you are a professional mastering engineer (in which case it is your job to obsess about this stuff, so that we don't have to).

I'll always use dithering when going to 16 bits as noynekker suggests at the mastering stage -- I've read somewhere (maybe the R. Izhaki "Mixing Audio" book?) that there's enough bit reduction going down to 16 bits that dither is typically worthwhile in that scenario.  
 
I think 24 bits is a bit more up for debate (as Anderton suggests, at 24 bits maybe any of the bit action is happening at such low levels that it becomes moot).
 
The question for me really is this: if I'm going from 32 bits (VSTi source file) to 24 bits, is 1) better to use Triangular dither OR just leave dither *off* and 2) maybe more to the point, will anyone even notice when I'm doing a pretty full production (i.e. not classical or something similarly dynamic).
 
 

The easiest way to hear what dithering does is to reduce the level of a piece of audio to -85dB, or whatever level gives you truncation. Then you can apply dithering and hear the difference. I did an audio example for an online webinar using an orchestra, and you could really hear what the dithering did. Realistically, few listening environments allow hearing those kinds of low-level signals but when you can, it helps. It's not something you "hear" as much as "sense."

To answer the original question: it's not important.
 
Use triangular dither when exporting to 24 bits, it'll be fine. Or don't dither at all. That'll be fine, too. But please don't upgrade to Producer for PowR-N dither alone.

lillloyd
will anyone even notice when I'm doing a pretty full production (i.e. not classical or something similarly dynamic).

 
I highly doubt it. I've only encountered a handful of musicians who, even under studio listening conditions, could tell whether dither was applied or not.

Me thinks that a 32 bit VSTi has nothing to do with audio depth, rather the code running as 32 bit (originally optimized for 32 bit OS).  The important question is, the output resolution of the VSTi is sample rates.  For example, most KONTAKT libraries have 24 bit output resolution (the instruments were sampled at 24 bit).  Outputs from virtual synths that DO NOT use samples, are also usually 24 bits but not always.
 
So, for your question, the fact that your VSTi is a 32 bit plugin would only be material if its output audio resolution isn't 24 bit.  
 
When your project is complete and then you mix down to 16 bit (CD quality), then some type of dithering would be in order, in which Craig's advice would be appropriate.
 
Caveat:  I think I know what I am talking about but it wouldn't be the first time that I don't know what I think I know.
 
Jim