I've never been a fan of dithering inside Sonar. That's not to say there is something wrong with the dithering functions, but I always use a dedicated dithering device and do it outside of Sonar. It's given me the best sound and least amount of audible noise. Something from Waves, PSP Xenon, or the tools in WaveLab 6 are what I use these days.

If someone knows dithering could you answer this:
 
Why we are suppose to use noise-shaped dither if it can be clearly heard? Why not triangular, it´s still does the same dithering and it´s quiet.

The levels are cranked pretty loud to hear it, but not above what my JBL 4410's can handle with regular program material at that volume.   If you can't hear it, you may want to check your system's self noise.  It may be masking the dither noise.

I don't know. If anything, it's just that my ears won't go there any more, though they're pretty good for my age, I think. I was monitoring direct from the headphone out on my interface, ultimately with the level control cranked to max, and couldn't hear a thing when muting/unmuting the noise sample. I'm pretty sure my E-MU 1820m and BeyerDynamic DT770 headphones should be reproducing those high freqs as well as anything, and the headphone out is extremely quiet.

I played around with it some more, and if I bump the track level up 6dB, I can just start to hear it, but any normal signal would be absolutely deafening at that monitoring level; it was downright scary to have phones on with the knob all the way up.

I still can't imagine anyone would hear this at normal listening levels without knowing what they were looking for. 

...if it can be clearly heard?

I don't think that's yet been clearly established, yet. Can you hear it?

and BeyerDynamic DT770 headphones

I love my Beyer 770s :) And I'm trying out the 990s now.

To Poco, the only test you should do to try to hear dither is to play it back at your normal-to-normally loud listening levels. The whole point of noise shaped dither is that they move the energy of the noise from where the ear is most sensitive to where the ear is least sensitive.  And all that energy still has to be there, so the high frequency noise has to be at a much higher raw level. But since your ear isn't as sensitive at that level, you won't hear it under normal conditions.

So, are you listening under normal conditions? Adjust your monitors until they are as loud as you would like to listen. Not as loud as they can go, and not as loud as you can stand. Turn them as loud as you would ever want to listen to your mix--I'm going to guess that it's going to be around 95 dB sound pressure level.  Can you still hear the dither?

if you have to crank up your monitors to hear the dither, then it's fine. That's normal. Try it with any dither and you'll probably get the same results.

Not intending to be argumentative here, but it really does appear that Pow-r 2 is the better choice.  At the same levels that Pow-r 3 becomes apparent, 2 is still below the threshold, and it would appear (from the documentation) that you get nearly the same benefit as 3.  All I'm saying is that based on that, I am going to use Pow-r 2 dithering.

Funny story about using headphones:  I recorded a jazz trio the other night, and all sounded well.  We all listened to every song all he way through.  Listening to the project at work today on headphones, it's apparent the Hammond player was keeping a secret.  About halfway through one of the tunes, his cell phone went off.  Fortunately, it's in the same key as the song... 

  About halfway through one of the tunes, his cell phone went off.  Fortunately, it's in the same key as the song... 

That's funny. I occasionally have the opposite problem: I'm playing piano, and the overtones make me think I hear my phone ringing so I stop playing, and... nothing.

brundlefly

...if it can be clearly heard?

I don't think that's yet been clearly established, yet. Can you hear it?

 
 
Well I meant it´s clearly something that can be heard sometimes.
 
 
Let me refrase my thoughts:
 
Why would I use something like Powr3 to shape noise that I can´t hear in the first place (using triangular), even if it´s the most ear-sensitive freq range.
But instead I´ll add a lot of noise to the range that can also be heard, as annoying hiss. It´s a bit stupid?

But instead I´ll add a lot of noise to the range that can also be heard, as annoying hiss. It´s a bit stupid?

 
Yeah, you're right, all those PhD audio engineers who developed this stuff are a bunch of dolts.
 
Just kidding. I understand the conundrum, but it's still based on the premise that you can "clearly" hear an "annoying hiss" from dither, which I don't accept.
 
Dither operates at a level, and in a way which is meant to mask quantization noise (which happens at all levels, not just the quiet parts) when rendering from 24 bits down to 16. The idea is that you can't distinctly pick out the noise, but you can perceive the reduction in distortion due to quantization.
 
As I've already confessed, I know very little about the details, but it seems clear that the more sohpisticated noise-generation patterns and distribution of the various Pow-r dither algorithms are intended to enhance the effectiveness of the perceived reduction in distortion (or maybe more aptly the substitution of less obnoxious forms of distortion) without making the dither noise apparent at audible frequencies and levels.
 
If there is any hiss detectable at the tail end of a recording, it's only at extremely high listening levels which would probably render you incapable of hearing hiss at the end, anyway. It's not a reasonable test to crank up the volume to abnormally high levels and then only listen to a sample of dithered silence without listneing to the ear-splitting sound levels that would precede it in practice.
 
 

"If there is any hiss detectable at the tail end of a recording, it's only at extremely high listening levels which would probably render you incapable of hearing hiss at the end, anyway. It's not a reasonable test to crank up the volume to abnormally high levels and then only listen to a sample of dithered silence without listneing to the ear-splitting sound levels that would precede it in practice."
 
This makes alot of sense. And for those who haven't read it, get Bob's book above, it's excellent.