I'm all adither about dithering...

I'm into some heavy mixing for a large project.  I record at 48k/24bit.  When I export my files out as 16/44.1 what dithering selection (or none) should I use?? 
 

http://forum.cakewalk.com/tm.aspx?m=2039306 Ethereal Entity's post explains the differences.

yorolpal


I'm into some heavy mixing for a large project.  I record at 48k/24bit.  When I export my files out as 16/44.1 what dithering selection (or none) should I use?? 
 

Since most of my mastering chains end with FG-X (sometimes that's all I have) I let FX-G do my dithering. When I only use Waves L3 as my final mastering step (on those rare occasions where the stars are aligned) I let it do the dithering.


IOW I never use SONAR's dithering. If I'm exporting in SONAR to 16bit it's usually just a "perusal" copy of the mix.

The only difference between one algorithm and the next is that some purport to be less audible than others. Given that dither noise is almost never audible to begin with, the choice of algorithms is essentially moot for most genres. 

Bristol_Jonesey

Strangely, I used Powr3 recently, and when I imported it into CD Architect, CDA reported "possible digital clipping at hh:mm:sss".

I would think that would need to be run through a limiter before dither.

I can't tell the difference when using dither but it's supposed to bring up any data in the lower bits before being truncated. I didn't think it raised the overall gain.

tacman7

Bristol_Jonesey

Strangely, I used Powr3 recently, and when I imported it into CD Architect, CDA reported "possible digital clipping at hh:mm:sss".

I would think that would need to be run through a limiter before dither.

It is run through a limiter before dither

What if you didn't dither at all?  I generally don't.  The last thing in my master chain is either FGX or ProL.

If you don't need to dither and you do, is any harm done?

If you don't need to dither and you do, is any harm done?

Not really. A small amount of noise is added, but it's way down in the least-significant bits and will pretty much disappear when you subsequently truncate to a lower bit depth.

The Sonar manual (PDF file) has a description of each of the dithering types and what it is best for. 

Here is a plug in I recently purchased.  It offer different dithers and you can actually see where you are getting distortion from common dithering in real-time.  It's a bit pricey but it is also pretty amazing.
 
http://www.sonnoxplugins.com/pub/plugins/products/pro-codec.htm
 
 
Kevin

If you want to clearly hear the differences between the various dither algorithms, do the following:

Take a single snare drum hit and run that thru a reverb with an extended tail (bounce it down).
Now listen to just the decay of the reverb on a good set of headphones.
Open up the headphone amp so you can hear the decay all the way to the noise-floor.
NOTE:  Be careful when doing this!

Now... apply each dither algorithm and bounce (each) down to a separate 16Bit audio file.
Using the procedure above (headphones with amp up loud)... listen the resultant 16Bit audio files.
You'll find that the reverb decays are "smoother" on some than others.
You'll also find that some dither algorithms are more audible than others.

After doing this test, I find Pow-r algorithm 1 to be the overall best in Sonar's offerings.
Smooth results... and the dither isn't too audible (comparatively speaking).
The dither noise in Pow-r algorithm 3 (noise-shaped) "irritates" my ears.

In regards to smooth sounding results (and dither noise relatively quiet) , I find Pow-r algorithm 1 and UV22-HR right about equal.

Before anyone says it (Hi Bit  ), this type of listening *does* magnify the results (not a typical listening scenario).
That said, if I know one algorithm produces smoother less-audible results (even though the difference may be extremely subtle), I'm going with that algorithm.

I've been using Powr-3 for my final export mix, since it seems to be "best" according to Sonar documentation.  Jim & Bristol, you have me tempted to switch to Powr-1.  I don't doubt the results of your experiment, but that's only 1 scenario, so I wonder if Powr-1 would be superior in other scenarios as well ... from a dense rock mix to a quiet orchestral mix to a pristine solo piano ...

And no, I don't plan to do the testing.  It would be great to hear from someone at Cakewalk on this topic.

I think I'm going to repeat the experiment.
I set this up on my secondary rig, which is in a room with a lot of ambient noise and only limited headphone volume.

When I get a chance I'll do it again on my main rig

Jim Roseberry

Interesting experiment. I've just done this will all 5 algorithms, and I must say Jim, after doing this I think I prefer Pow-r 1 as well.

 
Yeah, Pow-r alg. 1 was clearly superior (in this scenario) to my ears.
In my way of thinking, the "decays into the noise-floor" is the only time you'd year quantization noise.
(You're not going to hear it while music is playing at normal levels)
So I think the test scenario is pretty valid...
 
Note:  You're ears may not hear things exactly the same.  This type of test is pretty quick/easy to setup/execute.  Within a few minutes, you'll know which alrgorithm you prefer... and you can decide for yourself if the difference is appreciable. 

+1 to this test.

It reveals why it should be done whenever you are reducing bit depth, the benefit becomes clear.

Once you've heard the effects of not applying it they become easier to spot and choose the appropitate algo for your needs. I've yet to come across something where 'Triangular' hasn't been sufficient for me but I'm thinking now I might re-visit Pow-R 1.

I'm sure Pow-R 3 has more advocates on account of it sounds like it must be better than 1 because it's 3 right?... i.e.  My mixes haz 2 more Pow-R's than anyone elses...