To dither, or not to dither?

[dasdeck]

My 2 cents:
Depending on the DA converter, truncation noise, when coming from higher bit depth signals (64bit) can be quite strong. (I suspect that's what I'm hearing) I mix in headphones, and when I do not dither the signal at the output of my DAW, depth perception is quite off.
Since any dither imparts a sound, it may actually a side effect I'm hearing, nevertheless, the difference is there.

[enroe]

Since any dither imparts a sound, it may actually a side effect I'm hearing, nevertheless, the difference is there.

Hmm, interesting!

What kind of music? What dynamics? Is the signal or instrument fading
out into the silence? Has the track been normalized before?
Have you made an anonymous A-B comparison?

[dasdeck]

Since any dither imparts a sound, it may actually a side effect I'm hearing, nevertheless, the difference is there.

Hmm, interesting!

What kind of music? What dynamics? Is the signal or instrument fading
out into the silence? Has the track been normalized before?
Have you made an anonymous A-B comparison?

I'll have to a/b, thought (would have to create a dedicated setup, my A/B plugin will revert the signal back to 64bit) it is quite obvious when mixing. Without dither, I tend to overcompensate for sharpness, e.g. my signal will become way too peaky. It is very apparent with transient heavy material, like hip hop drums. The mix will sound very transparent, but boring and empty. The dither basically removes a certain amount of blur, wich would makes sense, if it is the truncation noise that is going away. Anyhow, I'm very aware that audio is a psychologically very tricky, but I'm pretty sure I'm already eliminating that variable to some extent. I'm using an airwindows dither, and those tend to be on the "colorful" side (very obvious with some of them), although I'm using a cleaner one, meant for monitoring (monitoring plugin 24bit).

[irpacynot]

Thank you, folks for all the replies.

[irpacynot]

One more last (I hope) question: Do you dither only when exporting the final master, or do you tend to do it (if you're going to dither) throughout a project (mid-project mixes, exported tracks using a lot of plugins, etc.)?

[osiris]

Only the one on TB Barricade.

[jupiter8]

It's by and large completely irrelevant. Have it on all the time if you believe it makes a difference and off if not. Worry about other stuff instead, that's using your time more efficiently. Don't worry about it. Test it if you're curious and hear for yourself.

[jamcat]

You are only going to notice quantization error very near -inf.

Let’s look at what dithering does:
It adds extremely low level noise to the high resolution (24-bit) mix. It’s so low that it would get quantized to -inf on its own when converted to 16-bit. But it may on occasion flip the LSB from 0 to 1 in the 16-bit conversion, if it just missed the rounding up cutoff, because sound mixing is additive.

The difference is pretty arbitrary unless it pushed an inaudible bit just into the audible range. This has the psychoacoustic effect of seeming to bring the ghost of sub-audible sound to the surface through partial representation. It results in slightly smoother fades to silence in the very quietest signals.

[irpacynot]

You are only going to notice quantization error very near -inf.

Let’s look at what dithering does:
It adds extremely low level noise to the high resolution (24-bit) mix. It’s so low that it would get quantized to -inf on its own when converted to 16-bit. But it may on occasion flip the LSB from 0 to 1 in the 16-bit conversion, if it just missed the rounding up cutoff, because sound mixing is additive.

The difference is pretty arbitrary unless it pushed an inaudible bit just into the audible range. This has the psychoacoustic effect of seeming to bring the ghost of sub-audible sound to the surface through partial representation. It results in slightly smoother fades to silence in the very quietest signals.

Hmm...okay.

Sounds like it could be quite useful, then.

But again, just curious if, after knowing that, if it's something that should be done simply when exporting the master, or throughout the project (mixes, submixes, etc.)?

[BertKoor]

Do it only when bouncing down to 16bits, so that should logically only be at final export of the master.

[jamcat]

You are only going to notice quantization error very near -inf.

Let’s look at what dithering does:
It adds extremely low level noise to the high resolution (24-bit) mix. It’s so low that it would get quantized to -inf on its own when converted to 16-bit. But it may on occasion flip the LSB from 0 to 1 in the 16-bit conversion, if it just missed the rounding up cutoff, because sound mixing is additive.

The difference is pretty arbitrary unless it pushed an inaudible bit just into the audible range. This has the psychoacoustic effect of seeming to bring the ghost of sub-audible sound to the surface through partial representation. It results in slightly smoother fades to silence in the very quietest signals.

Hmm...okay.

Sounds like it could be quite useful, then.

But again, just curious if, after knowing that, if it's something that should be done simply when exporting the master, or throughout the project (mixes, submixes, etc.)?

Dithering should only be applied during a downward conversion/export that reduces the original bit depth. You can actually add dithering with just a specially prepared white noise audio file mixed at just the right volume, no need for special plugins or converters.

But dithering is pretty pointless when only going down to 16-bit. In actual practice you’d have to have dog ears to hear a difference. It becomes far more useful the lower the bit depth is that you’re converting too, but at the same time, the more distinctly its effect sounds like a bed of white noise masking the tails.

And in actual practice, there is a near zero chance that you would be exporting below 16-bit. So is dithering still all that useful or necessary anymore? Probably not really. Using it or not is nothing to lose sleep over.

[osiris]

That's why I use it. I bounce down at 24 bit (48k), but the distribution wants 16 bit 44.1k. The tricky bit is loudness. I notice the LUFS jumps a little higher on the 16 bit dithered one.

[irpacynot]

I got it now. Thank you again, folks.

[soundmodel]

I guess the true answer is:

You need to listen to both and then decide whether the non-dithered quantization error sounds worse or better than the applied dither. The dither is meant to mask large errors in the quantization error.

However, if the algorithm to apply the dither is sensical, then it's expected that the dithered signal could in most cases sound better than the non-dithered one. Because it's meant to round out the quantization error (so it should not sound worse).

But you might also notice that more advanced forms of dither are more than just an on/off button:

https://external-content.duckduckgo.com ... ipo=images

So based on that, maybe you need to try out the switches and see which one fits best.

I am not sure whether the "Off" mode is for just already dithered files though. Could be. Which also reminds me of:

IMPORTANT: Dither should be applied only once. Otherwise you're mixing noise with noise and you might get phasing effects and/or a growing noise floor.

[irpacynot]

I guess the true answer is:

You need to listen to both and then decide whether the non-dithered quantization error sounds worse or better than the applied dither. The dither is meant to mask large errors in the quantization error.

However, if the algorithm to apply the dither is sensical, then it's expected that the dithered signal could in most cases sound better than the non-dithered one. Because it's meant to round out the quantization error (so it should not sound worse).

But you might also notice that more advanced forms of dither are more than just an on/off button:

https://external-content.duckduckgo.com ... ipo=images

So based on that, maybe you need to try out the switches and see which one fits best.

I am not sure whether the "Off" mode is for just already dithered files though. Could be.

Hmm...well, I'm keeping everything at 48khz throughout the entire project, individual tracks rendered, the mix, the master. However, most of my tunes are going onto Youtube, and it's my understanding they do 44.1. I'm not sure if I should export my master down to 44.1 with dithering or not.

And I'll be honest, I've tried to compare, but I couldn't tell you for sure if I truly noticed a difference (with dithering on or off). I seem highly susceptible to fooling myself with regards to such subtle changes.