Render To Disk And Dithering

Help, Support & Bugs Beginners Questions - Renoise
1

Hi,

When rendering to disk at 16 or 24 bit is there any dithering done? I’ve got a processor on the master that has a dither option but I want to avoid dithering twice.

2

In the Audio tab of the Renoise Preferences, there is a toggle to enable/disable Dithering. I would assume this affects both playback and rendering.

3

Thanks I thought it might but being this option is located at the device settings I’m not entirely sure. Can anyone confirm this?

4

I’m gonna chime in here and ask more questions because I don’t really understand dithering.

What’s wrong with dithering twice?
Why is it so important anyways?
Why am I confused?

I know you should dither when down-bitting, but what the heck does that dithering check-box in the preferences do?

Why is it an option when renoise should/could do this internally automatically?

Am I making any sense at all? Just got home and smoked a joint.

5

When you’re reducing bit depth there will quantization errors → Every sample value has to be remapped and they won’t all ‘hit’ a quantization step exactly so some sort of rounding of the sample value has to take place. You want this process to be random because if you say for example a sample value of 4.6 will always be placed on 5 you are correlating the quantization error to the signal which results in distortion.

If the process is random, ie 4.6 will sometimes be placed on 4 and some times on 5 the quantization error is no longer related to the signal, it is random, meaning it is noise added to the signal. And this is what exatly what dithering does → add a tiny bit of noise to the signal.

A little bit of noise is much '‘nicer’ than distorion and that’s why dithering is very important when reducing bit depth. You don’t want to add noise to the signal though when it’s not necesary, like you would when dithering twice.

6

Thanks Mans

7

Anyone?

8

I can. Dblue is right (as usual)…

9

Much obliged :)

10

In addition - the problem with this sort of distortion is that it is related to the digital signal levels rather than harmonically related to the music.
So it doesn’t sound nice.