Why Dither?

so this may seem like a noob question (prob is), but OK, I understand dithering is meant for when you are reducing bit rate.. say you are exporting a 24 bit project to a 16-bit file for CD burning, but why can't I just export as 24 bit and then convert it outside of Cakewalk using an audio conversion program?
 
I guess i just dont understand why dither?  Also should I be dithering as I work in the "Playback and Recording" area in preferences?
 
Thank You,
Adam

Cool thank you.  What if I am exporting my music to a WAV file, then convert it to MP3 outside of Cakewalk?   Do I need dithering then?   Is it just for bouncing to 16-bit?
 
Also do I need it on in the prefs or just while exporting?   
 
Thank you interpolated!

To answer your first question, you can export a 24-bit file and convert it in another program. Just bear in mind that not all programs will yield the same results, nor have the options available that SONAR does for that conversion.

You only need to worry about dithering during export (if needed).

tlw
If you're working with 24 bit audio then turn dithering off until you do the final actual conversion to 16 bit.

This isn't necessary. SONAR won't apply dithering to any bounce/rendering process unless there's a reduction in bit-depth.

Most of the answers given that try to explain dither are wrong in whole or in part. They may be easy to understand but they are wrong.
 
The short answer:
 
Dithering is just adding random noise at roughly the level of the lower bit depth step size before reducing bit depth and it does two things:
 
1. It makes the often ugly quantization distortion sound like noise - essentially because the distortion becomes based on a random signal (the dither) instead of your signal.
 
2. It preserves part of the signal that's below the lowest level possible at the lower bit depth. Instead of the very quietest parts being cut off completely, they are still there to the extent that you can hear them in the noise.

Please remember that only 16-bit stereo wav files can be written to a standard audio CD (although you can save mp3s and other formats as data on a CD).  That is one reason to dither when you export from Sonar.
 
I am sure others have their own methods, but when I am finally finished with a song, I export it three times:
 
1-As a 24-bit wav (no dithering) to save as the master, to send to the mastering engineer, and as a download for those who want high-quality (but large) files.
2-As a 16-bit wav (dithered) to write on a CD for listening purposes in different environments.  If a mastering engineer is making the final CD version for me, then I usually compress this one just as a trial version for my own use.
3-An mp3 to send by email or other methods for which a wav is too large.
 
We had a lively discussion on this forum recently about whether the particular dithering option in Sonar makes a difference a human can hear.  We all agreed that dithering in general can make an audible difference (though not always obvious).  When it came to the discussion about whether it mattered much whether you use Rectangle, Triangle, Powr-1, Powr-2, or Powr-3, I said no one could tell the difference.  Some people agreed and some did not.  I normally use Powr-2 but can't really justify that choice.

brundlefly

tlw
If you're working with 24 bit audio then turn dithering off until you do the final actual conversion to 16 bit.

This isn't necessary. SONAR won't apply dithering to any bounce/rendering process unless there's a reduction in bit-depth.

I did not know this. I always set dithering to "None" when exporting to the same bit depth. Even with this knowledge I'll probably keep doing that because I'm an anal weirdo... unless of course there is a reason to NOT use that method.

Well... Every day is a school day 
 
I've always left my dithering option as Powr-1 only based on my total lack of knowledge.
 
I work in 44.1/24 bit, export as a 24 bit WAV and then open in SF10 for normalising/compression. From SF10 I then save-as a 320kbps MP3 file for Soundcloud.
 
I do not burn to CD nowadays...
 
If Sonar doesn't dither if exporting as same bit depth then I guess I can just carry on as I am, but I'm tempted to do the same as Beep from now on......