fader clipping in a DAW... ok unless tracking or clipping the master fader?

[dannygold]

A lot of people seem to be saying if you clip a fader in a DAW that's bad. I don't see it that way. Certainly when TRACKING I leave plenty of headroom, but when mixing clipping an indivitual fader should not be a problem in my experience, nor from what the manufacturers of at least two major DAWS that told me. Hear me out...

YES: If you clip a fader in a DAW and send that clipping fader to a D/A converter you'll incur distortion because you're taking the huge headroom of 32 bit float or 48 bit fixed and knocking it down to 24 bit. What the clipping indicator in a DAW is really saying is "if you were to render this to 24 bits it would clip". If you do not render it to 24 bits you should not have a problem because of the huge headroom of 32 bit float or 48 bit fixed... something like 1000dB in the case of 32bit float. If you truly mix ITB just keep your master fader from clipping and you'll be fine even if individtual tracks clip. Aside from D/A example as per above other ways to run into 24 bit clipping problems are: Recording that clipping track to another track in the DAW via a bus... again you'll incur distortion because you turn the 32bit float or 48 bit fixed track into a 24 bit file... unless of course your DAW records 32bit files, whcih some do now. Another case where one might incur distortion would be plugins that only process at 24 bit, but I doubt many new plugins are not 32 bit float or 48 bit fixed.


A lot of people are going to disagree with me and say that clipping a fader in a DAW is always bad. I've seen them do so numerous times around here. So I setup this little test in DP. Should be no different in any modern DAW. Note in the picture below that I am clipping the heck out of the individual tracks which have identical sine waves on them... also note the trim plugins which each add 40dB of gain each, meaning not only is the individual fader super clipped as evidenced by the clip indicators, but so is the 2nd trim plugin.



Yet by attenuating the master fader and recording these several clipped to heck tracks to a new track via a bus you'll see the result is a pure sine wave in the picture below. No distortion is incurred because I managed the digital gain staging correctly for a purely ITB mix.



I do not, personally, consider keeping individual track from clipping during mixing part of managing ITB mixing. Unless I'm spreading things out to different faders on a console. Which isn't really ITB mixing but more a hybrid approach. When you tell me I'm wrong please tell me why the sinewave I recorded is free of distortion if clipping a 32 bit float based fader or plugin is so bad.

[tenderboy]

that should be true in theorie, as long as you have no plugins inserted postfader that can't handle hot levels

[fragletrollet]

Yep! Happy to see my fantasies have root in reality :p

[Skip Burrows]

In Theory, however in application, its always better to use the same voltage levels as you would in an analog console. IE 1.23 volts = Ovu and in digital this same voltage reference should = -20 from 0DBFS, INVHO.

[Brad McGowan]

Skip,

I've been following your other two threads and generally practice trimming my levels because I insert a lot of outboard gear in my mixes. But if you are using all floating point plugins (let's pretend we've verified this to be true) and truly keeping your mix in the box then I see no reason why one should adhere to 0VU = -20dBFS. As the OP stated, as long as you pull down your master fader and render a 24-bit fixed point mix that is free of clipping then you will not experience problems. This is how Cubase/Nuendo are designed to work as well.

Brad

[Skip Burrows]

Originally Posted by Brad McGowan

Skip,

I've been following your other two threads and generally practice trimming my levels because I insert a lot of outboard gear in my mixes. But if you are using all floating point plugins (let's pretend we've verified this to be true) and truly keeping your mix in the box then I see no reason why one should adhere to 0VU = -20dBFS. As the OP stated, as long as you pull down your master fader and render a 24-bit fixed point mix that is free of clipping then you will not experience problems. This is how Cubase/Nuendo are designed to work as well.

Brad

Well brad, Remember that most convertors still come at 1.23 volts = - 18. You said yourself that you use lots of Outboard. That equipment was designed to work best at the 1.23 volt reference. You can re-config your convertors to work at - 12 or hell even -10. But with your signal to noise error being over 100 db down from -20, Why? Many plugins use rather fuzzy math at best, and if you have nice old vintage gear, trust me that many of those classic units dont sound to sweet when being hit with upwards of 9 or even 10 volts!. Hey But I could be wrong. Good Chat.

[Brad McGowan]

I totally get that. I don't think the OP is proposing recording ridiculously hot signals. Although it's not uncommon for a snare drum to hit -1dBFS even with the gain all the way down on the mic preamp (RMS level of that snare is still around 0VU = 1.23V).

I think the OP is saying that once you've captured the signal using proper analog gain staging that one shouldn't worry about the level creeping up due to processing or fader rides. Or the summing of multiple tracks at the master bus for that matter, since you can simply lower the master fader.

I would disagree with your claim that "many plugins use fuzzy math at best". I think that's rather unsupported and dubious. I would claim that professional plugins from companies like Waves and UAD use very well implemented math that conform to the standards of the architectures for which they are developing.

Agreed--people should generally not push their analog gear past the operating levels for which there were designed, including analog stages of modern converters. But people should understand how their DAWs and plugins are designed to operate and feel enabled to work within those (more expansive) boundaries once they are inside the computer.

Brad

[dannygold]

Originally Posted by Skip Burrows

In Theory, however in application, its always better to use the same voltage levels as you would in an analog console. IE 1.23 volts = Ovu and in digital this same voltage reference should = -20 from 0DBFS, INVHO.

But if you're staying ITB what do voltages of the D/As matter? As long as the master output fader isn't clipping, the internal "clipping" really doesn't have anything to do with voltages... it has to do with floating point math. The DAWs clipping indictors are merely an early waring... if you're not going D/A there is nothing to worry about. You can keep in at -20 or at 0 or at zero plus 900dB and it still won't clip the 32 bit float.

[dannygold]

"I don't think the OP is proposing recording ridiculously hot signals."

Thank you for noticing Brad...

My exact quote, quite early in the post actually:

Certainly when TRACKING I leave plenty of headroom

[Slikjmuzik]

I know the converstion is already way past this, but going back to the OP's suggestion. Yes, I clip channels itb, as well as output busses. Not all of them of course, but for example.....I use a Dangerous 2bus. Obviously I create multiple stereo and mono output busses that see the channels of my Lynx Aurora. My tom bus and snare bus always clip read, however, my Lynx is not clipping and the Dangerous I know has an even higher decibel level that it can withstand before clipping. I believe the Dangerous won't clip till +25 or +26dbu I believe is what Bob Muller told me. Obviously the published specs play it safe, but I've sent some pretty sick levels to it when I first got and cranked the output volume knob and there was no audible/discernable artifacts upon controlling input volume hitting my Adams. So yes, at 24bit recording scale, you do have plenty of headroom to work with, I just hate that I have to set things up differently itb versus how I do on a console, so I just prefer doing things the old fashion way inside Cubase. I am not talking about input/tracking levels however. I track with peak levels hitting -12 generally for proper use of plugins later. I might hit -8 or -6 with vocals because I like how that make my UAD Fairchild plugin both react and sound, but that's a whole other topic.

[Brad McGowan]

If you are sending audio out of D/A converters and the meters on those tracks are saying you are clipping then you most certainly are clipping. Whether or not you can hear it is up for debate. I suspect a lot of people don't know what 2 samples of clipping on a snare drum sounds likes. I think the only thing to do is set up two mixes. One with D/A converters clipping like you normally operate and another mix where everything is trimmed back 10 dB. Leave off plugins and just do a level/pan only mix for simplicity. Try it and post your results. I'd be curious to hear the level-matched results.

Brad

[dannycurtean@yah]

Originally Posted by Brad McGowan

If you are sending audio out of D/A converters and the meters on those tracks are saying you are clipping then you most certainly are clipping. Whether or not you can hear it is up for debate. I suspect a lot of people don't know what 2 samples of clipping on a snare drum sounds likes. I think the only thing to do is set up two mixes. One with D/A converters clipping like you normally operate and another mix where everything is trimmed back 10 dB. Leave off plugins and just do a level/pan only mix for simplicity. Try it and post your results. I'd be curious to hear the level-matched results.

Brad

If its of any help, I tried the trim plugin -14 db down on a finished mix, and I have to tell you, I can finally use the V-Comp and the SSL buss compressors properly without leaving the threshold all the way down or being forced to insert a trim plugin before it to pad it down. So Skip is totally right about the reference levels of plugins and where they are designed to work. i think that Skip's idea is a completely revolutionary idea and a genuine one that has been hidden from us ITB guys for the most part. It made a huge difference for me, everything had more......air, everything was more comfortable, and I was compressing the same amount.

PS - I am talking about a trim plugin on every channel....

[Lawrence]

Track meters (inside the daw after recording and before hitting hardware outs) are almost irrelevant these days.

There are no clip indicators in the latest DAW offering's mixer channel meters, for good reason, it can't clip there. The only plug I found so far (that I personally own) that clips internally at the 24-bit scale limit is Waves Linear. The rest of them I never have to worry about. RenComp pulling 3db compression with an input level of +10 should sound just like RenComp pulling 6db with an input level of -6... if the attack/release are set the same and the level is adjusted on the other side, they should null. The only difference will be where the thresholds are set.

Anyway, many plugs have I/O trims anyway so... why bother sticking a digital trim on every channel? Most people have no real idea of how much headroom is in these daws and how much this kinda stuff doesn't even matter. If you're going out to hardware and you feel it's too hot for the hardware for some reason or another ... pull the bus fader down?

If people would stop chasing unicorns and just work on the craft it all kinda works itself out. No offense meant to anyone here by that comment, just in general.