LIVE dithering

[chrispnyc]

I think everyone is confusing bit depth and bit rate. The 32 float bit depth is representative of internal processing only in Live. The majority of plug-ins (commercial at least) operate at 32 bit float. Some such as Ozone, Waves (I believe) operate at 48 point. a well written plug-in will convert the 24 bit audio signal to 32 or 48, perform its calculations and then dither back down to 24.

The bit rate that is set in preferences is the rate at which new audio is created when recording.

If you think that not dithering internally when doing calculations doesn't add up, I highly recommend you check out "Mastering Audio" by Bob Katz. It is the best book I have read about preserving signal quality.

Check out his website http://www.digitaldomain.com. there are a bunch of excerpts and free articles on there about this stuff that is really enlightening.

[huffcw]

You don't really need to render to 32-bit unless you have 32-bit files in your project

Yes you do the internal audio path (VSTs, summing, processing) is 32 bit.

Good point!

[melocoton]

Check out his website http://www.digitaldomain.com. there are a bunch of excerpts and free articles on there about this stuff that is really enlightening.

Wrong Digital Domain http://www.digido.com/

The thing I've always wondered is shouldn't Live be adding dither when converting from the 32 bit output of the plugin down to the 24 or 16 bit depth of the project?

[Hedroom]

Ok... I'd like to take advantage of some of your knowledge here people...

If I'm working at 24 bit and I stick a Waves L2 on my master with it's dither setting on 16, will exporting to 16 bit do the dithering properly?

Regards

Gareth

[huffcw]

The thing I've always wondered is shouldn't Live be adding dither when converting from the 32 bit output of the plugin down to the 24 or 16 bit depth of the project?

This is my understanding (please correct me if you think I am wrong)...

I don't think it matters or is needed while working within Live because everything is operating at the highest level (i.e., Live will process and mix in 32-bit floating regardless of whether or not your audio files are 32-bit - and there is no need to convert things from a lower bit depth to a higher one). You can set Live to record files as 16-bit audio files, but this doesn't change the fact the the project as a whole is still operating within Live at 32-bit floating (and the 16-bit files fit easily into that space).

Where dither matters is when the project files are converted down to a lower bit depth at then end of the process (in particular, exporting out of Live's 32-bit floating environment into one 16-bit file).

As far as the output of your audio card is concerned, it's not much of a concern unless you audio card operates at 16-bit (but in that case you can't do much about it because you are talking about hardware converters). However, most audio cards these days operate at 24-bit integer - and 32-bit floating converts to 24-bit integer without any audible audio degradation (remember there is a big difference between integer and floating and 24-bit integer is essentially the same as 32-bit floating as far as quality).

32-bit floating really only provides an internal processing advantage over 24-bit integer - e.g., when mixing digitally it provided increased dynamic range. There is really no need to record your audio input at any higher than 24-bit, for one your card's converters have a maximum dynamic range of 24-bits. However, 32-bit floating comes into play when you start mixing that 24-bit audio in Live - providing the increases in dynamic range.

There is a lot of debate over 32-bit floating being any better than 24-bit fixed. More in-depth reading comparing fixed integer to floating point: http://www.rane.com/note153.html

All in all, the whole discussion doesn't mean a whole lot. Things like microphone placement, your hardware converters and preamps etc. have a much greater effect on the final sound. I am think that the bit depth should be the least of our worries.

[lunabass]

Ok... I'd like to take advantage of some of your knowledge here people...

If I'm working at 24 bit and I stick a Waves L2 on my master with it's dither setting on 16, will exporting to 16 bit do the dithering properly?

I'm not entirely sure that it will. I use Pro Tools for my mastering (about all it's good for in my studio since I made the switch to Live) and it states that dither should be the last thing in the signal chain. This means that there should not be any other DSP stages including fade outs etc after the dither stage or the dither is undone...all you've really done is just add noise. If you read the waves literature it makes a point of saying the same thing. If your going to use the L2 for dither it must be the last thing in the signal chain. This is why Master Fader inserts in Pro Tools are Post Fader...if the L2 is in the last insert point on the master fader it is the last device in the signal chain.

In Live the plug-in inserts are pre fader. So the L2 would apply dither before volume automation...which it is not ideal. Live6 could fix this with the inclusion of Post fader insert points on the master fader...if it is included (that way I could almost ditch Pro Tools for good)

The following 2 quotes are the best advice in this thread in my opinion. It's good to have an understanding of these things but it's easy to get bogged down in it too. If you cant hear the difference then dont worry about it...if it sounds good it is good.

but in the end: let your ears be the guide. if you can't hear dithering yourself, stop wondering about it and start makin' some noise

All in all, the whole discussion doesn't mean a whole lot. Things like microphone placement, your hardware converters and preamps etc. have a much greater effect on the final sound. I am think that the bit depth should be the least of our worries.

cheers

[donnydonny]

In Live the plug-in inserts are pre fader. So the L2 would apply dither before volume automation...which it is not ideal. Live6 could fix this with the inclusion of Post fader insert points on the master fader...if it is included (that way I could almost ditch Pro Tools for good)

seriously, i don't know why EVERY DAW doesn't have this feature. at least on the master fader if not on every channel (a la Cubase).

[Hedroom]

If your going to use the L2 for dither it must be the last thing in the signal chain. This is why Master Fader inserts in Pro Tools are Post Fader...if the L2 is in the last insert point on the master fader it is the last device in the signal chain.

In Live the plug-in inserts are pre fader. So the L2 would apply dither before volume automation...which it is not ideal. Live6 could fix this with the inclusion of Post fader insert points on the master fader...if it is included (that way I could almost ditch Pro Tools for good)

cheers

Interesting... I'd never thought of that. I would have thought though (and I may well be wrong!) that the only reason that you wouldn't want to have the master fader after L2 would be because it could cause the exported file not to be normalised to the ceiling set in L2. Could it actually introduce other artifacts too?

Is the normal procedure with the L2 in a 24 bit projects to stick it on the end then render to 16 bit? Or would this activate some dithering process inherent in the audio software too?

[lunabass]

Could it actually introduce other artifacts too?

As far as I understand it, if the dither is not the last thing in the signal chain and some other dsp process happens after dither then the effect of the dither is undone and all you're left with is the dither noise...no gain in fidelity (for want of a better word) just more noise. I dont necessarily understand why the dither is undone but it mentions this in the waves literature i've read in the past...can anyone explain this?

Is the normal procedure with the L2 in a 24 bit projects to stick it on the end then render to 16 bit? Or would this activate some dithering process inherent in the audio software too?

In your 24bit mastering session when you're about to render your final 16bit master to disk , stick the L2 as the last thing in the chain (this cant be done in Live, so another program is needed). The audio is passed through the L2, dither is applied and then the 8 bits are lopped off the bottom as it's being written to disk...voila 16bit file.

[Hedroom]

Cheers