# Always use dither when bouncing



## Kejero (Nov 5, 2015)

Ian (whom I'm sure a lot of people know around here) gives the following advice in http://productionadvice.co.uk/when-to-dither/ (this blog post): "Always use dither when saving out to 16 or 24-bit files". The http://productionadvice.co.uk/dither-or-distort/ (video he mentions) is worth checking out too to grasp what he's talking about.

It's the first time I've heard anyone say that. Like he mentions, the advices I've always heard are "Never dither more than once" and "Only dither if you're bouncing to a lower bitrate."

I always thought dither is only needed if the file you're delivering will/may be converted later (by yourself or someone else) to a compressed format like mp3, because during the conversion, artifacts may be created. So my own rule of thumb has always been: "Only dither on the final bounce (be it 24 or 16-bit, regardless whether my original audio files and project settings are 32, 24 or 16), and only if the file may later be converted to a compressed format."

Looks like I've been completely misinformed about the at least part of why dithering is needed, and apparently when. I'd be interested to hear some thoughts about this, since needless to say, I've been taken by surprise by this revelation!


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## KEnK (Nov 5, 2015)

Very interesting Kejero-
I also was under the impression that dithering should only happen once and when lowering the bit rate.
I've learned a lot from Ian Sheperd's blog and vids, and he names legendary Paul Frindle as backing him on this-
It bears investigation-
Anyone else have any thoughts on this?

k


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## d.healey (Nov 5, 2015)

Don't bother with dither - http://ethanwiner.com/dither.html


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## ZeeCount (Nov 5, 2015)

d.healey said:


> Don't bother with dither - http://ethanwiner.com/dither.html



That's not quite what he said in that article:

"To be clear, using dither is never a bad thing, and it can sometimes help on soft material recorded at very low levels. So I'm not arguing against using dither! But I've never heard dither make any difference when applied to typical pop music recorded at sensible levels. I'm merely pointing out that not using dither is never the reason a newbie's mixes sound bad."


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## d.healey (Nov 5, 2015)

ZeeCount said:


> That's not quite what he said in that article:


 just my opinion


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## ZeeCount (Nov 5, 2015)

d.healey said:


> just my opinion



Of course, we can only post our own opinions on these things. I just wanted to point out that that wasn't necessarily what the link you posted was trying to say.


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## d.healey (Nov 5, 2015)

It's a good link, you should watch the audio myths video, very informative!


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## ZeeCount (Nov 5, 2015)

d.healey said:


> It's a good link, you should watch the audio myths video, very informative!



Yeah, I've seen it before, it is an excellent presentation. They make a lot of good points about how the psychology of hearing and visual factors have a large impact on how we perceive audio.

As for dithering, I personally have never felt like it made a difference to the stuff I produce and, as a general rule, if I don't hear something doing anything I don't use it. I understand the mathematics of how it works but we're talking about changes that are so subtle that I would never notice them in a mix unless it was just a solo instrument at very soft levels.


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## 1982m (Nov 5, 2015)

Dither only once at the final stage & if you're going to down a lower bit rate.


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## Gerhard Westphalen (Nov 5, 2015)

Although I don't know all that much about digital audio, it's my understanding that dither will be applied by A/D and D/A converters so I don't see why adding it additionally to the file. If it were going to a D/A that didn't have dithering for some reason then it would be important to dither since it reduces quantization error.


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## tomaslobosk (Nov 7, 2015)

When reducing bit-depth of an audio file, quantization error happens, and this is translated into harmonic distortion, dithering "solves" this issue randomizing quantization error values, so instead of harmonic distortion you get a constant noise floor.
That's all about dithering.
It definitely helps with music at near-zero levels.


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## EastWest Lurker (Nov 7, 2015)

Maybe for bit rate downsizing with very quiet source material. Personally, I have never heard the difference.


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## 1982m (Nov 7, 2015)

Try listening to reverb tails closely using different dither types & bit rates. There are quality differences although it probably won't make a huge difference to the listener on a full mix.
It's similar to comparing 320 mp3 & 16b Wav.


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## tomaslobosk (Nov 7, 2015)

EastWest Lurker said:


> Maybe for bit rate downsizing with very quiet source material. Personally, I have never heard the difference.


It's very noticeable!, check this out:

*CAUTION! VOLUME WARNING:*

Without dithering:
https://drive.google.com/file/d/0B3iPwahfmBfXMF9ob25iTHJwZ28/view?usp=sharing
With dithering:
https://drive.google.com/file/d/0B3iPwahfmBfXSE40QWJOdEF0NUU/view?usp=sharing


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## tomaslobosk (Nov 7, 2015)

You can even do noise-shaping so that the noise-floor isn't that noticeable:
https://drive.google.com/file/d/0B3iPwahfmBfXc0QzcFFYU0RjVXM/view?usp=sharing


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## Kejero (Nov 7, 2015)

TomiLobosK said:


> When reducing bit-depth of an audio file, quantization error happens, and this is translated into harmonic distortion, dithering "solves" this issue randomizing quantization error values, so instead of harmonic distortion you get a constant noise floor.
> That's all about dithering.



Yeah I believe that is the conventional wisdom on the matter. But if I understand Ian correctly, he's saying that you should dither *even when you're not reducing bit-depth* (unless you're bouncing to 32 bit). Hence this topic.


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## germancomponist (Nov 7, 2015)

You can hear the differences in a well treated room with best speakers or with a best headphone, this is true.

But 99,9% of all listeners do not listen to music in this way.


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## Kejero (Nov 7, 2015)

germancomponist said:


> But 99,9% of all listeners do not listen to music in this way.



I never liked that argument. If you only make music for those 99,9%, you're obviously not doing it for the art. Why even bother doing it at all.


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## Nick Batzdorf (Nov 7, 2015)

Ethan Winer is interesting and I like him personally, but I would recommend that anyone who reads his opinions seek some more opinions. Normally they'll differ from his. 

I'd be happy to explain how dither works when I have time, but the short answer is what 1982m says. Use it when you're reducing bits, and do that only once - at the last stage.

Whether you hear it is highly program-dependent, but there can often be a serious difference to low-level detail. In samples, maybe not, but definitely in recordings.


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## tomaslobosk (Nov 7, 2015)

Kejero said:


> I never liked that argument. If you only make music for those 99,9%, you're obviously not doing it for the art. Why even bother doing it at all.


Exactly, I know how dithering works, I like how it sounds, and if I can use it to enhance my listening experience, why not?


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## germancomponist (Nov 7, 2015)

Kejero said:


> I never liked that argument. If you only make music for those 99,9%, you're obviously not doing it for the art. Why even bother doing it at all.


Huh, this was not meant as an argument, but it is the truth, fact!
I would like it if people would spend more attention to all this, but they do not ... .


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## Kejero (Nov 7, 2015)

Sure. But I like to know that the 0.1% who do, will appreciate the effort.

I recently watched the Lost Interview with Steve Jobs, in which he said something along the lines of exposing people to the best possible version of things, so they get accustomed to what actual quality is, as opposed to accepting subpar crap. I mean, _of course_ I'm aware that the majority of people are perfectly fine with 128 bit mp3, but that doesn't mean everybody is, and it doesn't mean I have to be.

I no doubt completely f*d up the quote above, so here's another one (also from Jobs) that may drive my point home even better:



> When you’re a carpenter making a beautiful chest of drawers, you’re not going to use a piece of plywood on the back, even though it faces the wall and nobody will see it. You’ll know it’s there, so you’re going to use a beautiful piece of wood on the back. For you to sleep well at night, the aesthetic, the quality, has to be carried all the way through.


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## germancomponist (Nov 7, 2015)

I talked about this with a befriended and well known mastering Guru just 2 minutes ago, and he said:
"NEVER dither more than once. Only dither when reducing 24 bit to 16 bit. This is common knowledge.
Basic engineering. Nothing has changed."


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## Kejero (Nov 7, 2015)

So, _not_ Paul Frindle then, I presume?


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## germancomponist (Nov 7, 2015)

My friend


Kejero said:


> So, _not_ Paul Frindle then, I presume?


What I can tell you is that my friend mastered a lot of Hollywood best sounding music ... .


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## tomaslobosk (Nov 7, 2015)

germancomponist said:


> "Only dither when reducing 24 bit to 16 bit."


Only dither when reducing to any bit-deph*


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## Kejero (Nov 7, 2015)

Well I've been following the conventional advice pretty much my entire "career", and I'm not quite ready to change my dithering habits. But I've read some good advice from Ian on other stuff and his 'Perception' plugin has definitely helped me in my mixing and mastering, so when I read a theory like this coming from him, I get curious. And I ask myself, there has to be a reason why he's saying something that goes against common knowledge and practices. A reason other than recreational drugs.


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## germancomponist (Nov 7, 2015)

Kejero said:


> Well I've been following the conventional advice pretty much my entire "career", and I'm not quite ready to change my dithering habits. But I've read some good advice from Ian on other stuff and his 'Perception' plugin has definitely helped me in my mixing and mastering, so when I read a theory like this coming from him, I get curious. And I ask myself, there has to be a reason why he's saying something that goes against common knowledge and practices. A reason other than recreational drugs.


I understand you 100%!
My suggestion is: Experiment!
And: Salut my friend!


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## Nick Batzdorf (Nov 9, 2015)

And if avoiding the harsher sound of truncation - just removing the quietest eight bits - is free, why would you not want to use it?


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## gsilbers (Nov 9, 2015)

Talk about splitting hairs!!


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## Goosewinkle (Nov 17, 2015)

I think Ian's advice is the same as the tenet of "dithering before any bit-depth reduction", since he's talking about converting from 32-bit floating point in the DAW to a 16- or 24-bit wav file.

Also it's not related to MP3 or compression algorithms. And I would agree that the effects are extremely minimal even at 16 bits, much less 24...


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## Igor Sena (Jun 29, 2018)

One thing that has always confused me was wether i should dither if i had a project with 16 bit sample library/samples and 24 bit sample library/samples mixed.

Have you guys/girls tried dithering in such a case and how did it went?


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## Divico (Jun 29, 2018)

My 2 cents.
Dithering makes only sense when you are up to lower the bit rate. Why?
Because it is supposed to tackle audible quantization distortion by basically introducing noise.
Thats why you DONT want to do it more than once. Nobody likes a high noisefloor (ok maybe some vinyl and tape freaks do).
Dithering is the most audible in silent passages and especially on reverb tails.
The point with dithering from the higher bit depth while mixing to 24 bit at the A/D is interesting and new to me.
As to dithering all the time I have to say that I am really sceptic about this due to increasing noise floor. It seems we have to get a compromiss here between quantization distortion and a noisy record.
What I definetly do not agree with is that noise in old recordings sounds good and that this is the difference between cold digital and pleasant analog. This is rather due to saturation effects not hiss. At least I hate noisy records.



Igor Sena said:


> One thing that has always confused me was wether i should dither if i had a project with 16 bit sample library/samples and 24 bit sample library/samples mixed.
> 
> Have you guys/girls tried dithering in such a case and how did it went?


I think you will gain something.
1. Because part of the audio was originally 24bit.
2. The information you add during processing -> especially reverb will benefit


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## Igor Sena (Jun 29, 2018)

Divico said:


> My 2 cents.
> Dithering makes only sense when you are up to lower the bit rate. Why?
> Because it is supposed to tackle audible quantization errors by basically introducing noise.
> Thats why you DONT want to do it more than once. Nobody likes a high noisefloor (ok maybe some vinyl and tape freaks do).
> ...



Hey, there, Divico =)

Thanks alot for your reply.

This dithering stuff is such a complicated mess. On one hand, like you also said, i always knew and heard you should only dither when lowering bit depth and only once but then it got complicated exactly because of my first question: If one should only dither when lowering bit depth but had a song/project/track with 16bit and 24bit elements combined it would be a contradiction of those "rules".

Thanks for your input =)

P.S. Just checked your music. Really nice and different stuff there. That Apollo 13 track is so awesome!


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## Divico (Jun 29, 2018)

Igor Sena said:


> Hey, there, Divico =)
> 
> Thanks alot for your reply.
> 
> ...


Thanks.

Keep in mind your DAW is upscaling your music. Reaper for example uses 64 bit float for mixing. Thats also the point in the video that dithering could be useful when rendering even to 24 bit. Imo when going down to 16 bit you should do it. But just once


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## Igor Sena (Jun 29, 2018)

Divico said:


> Thanks.
> 
> Keep in mind your DAW is upscaling your music. Reaper for example uses 64 bit float for mixing. Thats also the point in the video that dithering could be useful when rendering even to 24 bit. Imo when going down to 16 bit you should do it. But just once



Got you.

Thank you very much once again!


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## jcrosby (Jun 30, 2018)

The best way to understand what quantization error sounds like is to add a bit reducer plugin after a reverb plugin and listen to the reverb fade into squared-off bits.... Reverb tails are generally the easiest place to hear it easily... Similar to the noise you occasionally see when a scene in a film fades to black.


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## Divico (Jun 30, 2018)

jcrosby said:


> The best way to understand what quantization error sounds like is to add a bit reducer plugin after a reverb plugin and listen to the reverb fade into squared-off bits.... Reverb tails are generally the easiest place to hear it easily... Similar to the noise you occasionally see when a scene in a film fades to black.


Its even simpler. Do it like me. 
I wanted to pull a hair out of my DT880s driver and ended up with a hole in the damn membrane.
Now a sine wave sounds like a [email protected]#%$ saw wave. What an irony.


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## richiejazz (Jun 14, 2019)

Igor Sena said:


> Hey, there, Divico =)
> 
> This dithering stuff is such a complicated mess.




Indeed! Do I dare venture into what dithering types/shapes are the best to use?
I generally dither when mastering down to 16 bit only and using Logic I just use the Apogee setting. I heard somewhere down the line this was the 'cleanest'....? I noticed a couple of producers on the rockier side used the Pow R setting so Ive copied this for heavier tracks. Honestly Ive never noticed the difference. Briefly switched to using the Waves one on whichever was last in the chain (usually an L3) and avoided Logic's bounce dither. But now I just turn off the waves ones and for ease of knowing exactly what Im bouncing just leave it to logic. As has been said - I presume you would never use a plugin one followed by the DAW...


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## Rob Elliott (Jun 14, 2019)

I could never hear any difference. I get a sense that my dog can BUT he is a terrible communicator on how it improves the bounce.


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## robgb (Jun 14, 2019)

I used to dither a lot but I've gotten more decisive in my old age.


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## richiejazz (Jun 14, 2019)

Rob Elliott said:


> I could never hear any difference. I get a sense that my dog can BUT he is a terrible communicator on how it improves the bounce.



Ha, exactly! Think its time to tick dithering off the list of things to procrastinate over..


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## Beat Kaufmann (Jun 15, 2019)

Actually, everything's been said. Still some theory to the video of Ian Shepherd:
With 8dB one has a theoretical dynamic range of 48.16 dB, with 16Bit one of 96.33dB and with 24Bit one of 144.49dB.

The video by Ian Shepherd shows a sine tone with a level of -65dB. With 8Bit this sound can theoretically not be captured at all. But he does it...?
Afterwards he shows the same sound with 16Bit resolution. OK this works. But the artefacts are at -125dB. But also these are far outside the possibilities of a 16Bit recording.

So, Ian Shepherd should take this video from the net. It is misleading in my eyes.

Personally I only use the dither when I have to reduce from 32Bit/24Bit to 16Bit, as long as the music itself doesn't contain any noise. My live sound recordings have enough noise anyway, even if they don't make much noise.

Beat


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## dgburns (Jun 15, 2019)

@Beat Kaufmann Yes!

Natural room noise is the best form of dither imho.


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## Fredeke (Jun 16, 2019)

Sorry I don't have the references underhand now, but here's what I remember from a course on dither:
- dither increases dynamic by smearing out quantization noise.
- modern software dither automatically, so you shouldn't worry about it.
- nevertheless, adding dither upon dither doesn't make anything worse (or better), so it won't hurt if you dither your bounces unnecessarily.
From that I would conclude: when in doubt... do it. At worst it won't make any difference.



dgburns said:


> Natural room noise is the best form of dither imho.


It's not the same. Room noise gets quantized along with everything else, and the purpose of dithering is to get rid of quantization artefacts. (Now I agree that a noisy recording will probably mask those artefacts more than a cleaner one, but still, it's not the same.)


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## dgburns (Jun 16, 2019)

@Fredeke NOPE! modern DAWS do not dither automatically.

Many have dither options, but when you move in and out of the DAW, you get truncated to 24 bit pcm from 64 float (assuming you're working with a 64 float engine and are writing 24 bit pcm files) No dither required when recording to 64 float files to disk, if you could. I/0 interfaces MIGHT have dither, but it would be on a case by case basis to the best of my knowledge. We're talking the very lowest volume stuff here anyway.

Basic triangle dither is safe to use in succession - especially in production. Careful with any noise shaped dither anywhere before the final output. Noise shaped dither pushes the distortion (noise or whatever voodoo algo they are using) to the extreme frequencies so we don't hear it as much) and it's usually applied to the bottom two bits of data in a pcm file. The more random the algo, the better apparently.

You want to dither when you go from a higher size to a smaller size. I still can't always tell the difference when applying dither to the output, but it is supposed to increase PERCEIVED resolution, so a smaller data rate file can sound better then it normally would without dither- it is supposed to retain the resolution of the higher data rate.

Room tone is a great dither.


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## Fredeke (Jun 16, 2019)

dgburns said:


> @Fredeke NOPE! modern DAWS do not dither automatically.


I stand corrected.


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