Clipping Logics Output 1-2 Channel ?

[altairuk2008]

Hi.

 

I have a few questions regarding logics output1-2 channel and also the Master Volume Fader.

 

1. I was under the impression that if you were to go into the red on the output channel by any amount that you should hear digital clipping... why is this not the case in Logic ? I can often push the output channel a few db into the red before i even hear any noticeable artifacts ? surely in the digital domain the second you go over 0.0db you are going to hear the horrible sound of Digital Clipping ?

 

2. I have been told that if you push the output 1-2 or the Master Volume up so the output goes into the red you a theoretically brickwalling your mix as pushing it into the red makes it act as a limiter and this is the reason why you dont hear clipping when you go over 0.0db on the track... im not sure how true this is and this is why im posting on this forum.

 

If someone could explain to me how this all works it would really be appreciated.

 

Cheers

[David Nahmani]

1. The minute you go over 0.0 dBFS on the Out 1-2 meters, you are distorting your audio signal by adding digital clipping. That doesn't mean you're going to hear that distortion right away. Depending on the audio signal, you may be able to push the level quite far into the red before you hear the clipping. Nonetheless, it is happening.

 

2. This would only be true if a brickwall Limiter worked by simply clipping your signal. Obviously, if it was the same thing to limit or clip the signal, there wouldn't be any need for limiters (all you'd have to do is clip with the volume fader). Limiting is ... a little more advanced than digital clipping.

[altairuk2008]

Cheers for the quick response david...

 

if i could refer you to T-Powers posts in this thread http://www.dogsonacid.com/showthread.php?threadid=580545&cache=18

 

could you confirm that what he is saying is correct or not ? he is saying putting the master output to +6db works as well as any limiter he has used before, so long as your mix is mixed well enough to handle pushing it by +6db.

 

Its just confusing to me as iv always been told that under no circumstances should you ever push the output1-2 fader into the red.

[David Nahmani]

Its just confusing to me as iv always been told that under no circumstances should you ever push the output1-2 fader into the red.

 

Again, it's going to sound totally different depending on the material. Saying "Under no circumstances" assumes too much about those circumstances. Of course if you want a faithful reproduction of an acoustic vocal recording, don't go in the red. But what if you want to give a little edge to a dance or hip-hop beat? Give it a go, why not? And if you like the way it sounds, why not use it? While many theoreticians will tell you what you shouldn't do under any circumstances, tons of producers busy selling millions of records are doing it every day, I can guarantee you.

 

At the end of the day, use your ears.

[ski]

I read that post. I don't buy it. If I start to go into the red on any of my outputs I hear distortion every single time.

 

But hey, try it. If it works for you then it works. Like David said, use your ears. However, AFAIK there is no secret brick wall limiter built into Logic's master fader. In fact, the master fader is really nothing more than a "remote control" for bringing the levels of all of your outputs up or down simultaneously (without actually showing a reflection of the gain increase/decrease on the actual faders o the outputs. In other words, it works like a VCA trim). Even the poster on that website said as much.

 

And sure, clipping a signal gives the waveform the appearance that it's been brickwall-limited, but that's about it.

[David Nahmani]

AFAIK there is no secret brick wall limiter built into Logic's master fader. In fact, the master fader is really nothing more than a "remote control" for bringing the levels of all of your outputs up or down simultaneously (without actually showing a reflection of the gain increase/decrease on the actual faders o the outputs. In other words, it works like a VCA trim). Even the poster on that website said as much.

 

(I haven't read the linked article)

 

In a way, Logic, like any other DAW, is limited to spit out samples at a max value of 0 dBFS. So raising the volume on the Out 1-2 (or on the Master Fader, which would give you the exact same results) usually gives you a sensation of increased perceived volume, along with the digital clipping distortion. That's a pretty crude way of limiting, but maybe that works fine for him, his tastes and the material he mixes.

[ski]

(I haven't read the linked article)

 

Not really necessary either. And the overall appearance of that website will make you go blind.

[David Nahmani]

Not really necessary either. And the overall appearance of that website will make you go blind.

 

When I originally clicked the link, it took me about half a second to automatically close that window. It was like a reflex, rather than a decision.

[altairuk2008]

lol cmon guys the site isnt that bad, iv seen countless sites which are much worse.

 

ill just paste what he said so you dont have to visit the site...

 

"master out at +6db in Logic works better than any limiter i've tried, totally transparent and no colouration, brickwalling as it should be, just get your mixdown right first."

 

 

 

"basically, in logic 7 you have 2 faders for the main out, named, output 1-2 and master volume. Put the master volume fader up +6, the reasoning behind doing it on the 2nd fader is that you can have your multimeter setup on the output 1-2 track so you can verify that you are not running the unpushed level past 0db, and therefore have a better idea of how your frequencies are balanced before being truncated by the brickwall effect, i also run an instance of chanEQ before the multimeter to fine tune my overall levels and make mastering eq adjustments.

 

I tried Ozone 3, its the best of the rest and is an interesting plug in its own right but it does colour the sound field even in brickwall mode.

 

As a side note, you will find yourself using less limiting on each instrument in the mix using this method as you instantly can achieve a "mastered" feel to the track and i have tended to end up with a lot more dynamic range in my mixdowns as a consequence, it can make you lazy though so you have to make sure not to use this as a quick fix for a shabby mixdown."

 

 

 

"pushing individual outputs up +6db will NOT give you the same results, and will make it a complete and utter pain in the arse should you decide you dont want to listen to the track with the mastering stage on while you are writing or just dont want to limit as much as 6db.

 

theres one simple reason for doing it this way, you can then send an unmastered (non +6db clipped) for mastering along with a reference for the mastering engineer so he can hear that he can get at least 6db out of the track with his hardware and far superior limiters.

 

how your track is mixed down will dictate how much more volume a mastering engineer can get out of it, and if you employ the method i've shown you can find out instantly with no fuss if your mixdown can take an extra 6db, as a poorly balanced mixdown will fart at +6db.

 

this was the solution i came to after months of going back and forth with stewart hawkes at metropolis and spending a LOT of money doing so, employ this method and your mastering engineer will end up not even having to tweak your master eq, he'll just limit it till it squeaks."

 

 

 

 

"with logic you CAN run the master +6db into the red if your mix is under control, running individual channels into the red causes "mushiness" at the master in Logic, its better to be diligent and keep your individual channels as near to 0db as possible, and have your monitoring level on master output doing the same (use the multimeter its invaluable), by clipping the master output +6db you are applying the limiting "post" master channel, so you can have if you wanted a master compressor or mix enhancer etc, to clip all the individual tracks would be limiting "pre" to your mastering stage which is clearly problematic as your master compressor should always be "pre" to your final limiter."

[David Nahmani]

IMO this guy has it backward. "Red" levels on the track or instrument channel strips do not introduce distortion, red levels on output channel strips do. Edited June 30, 2008 by David Nahmani

[ski]

Beauty (or web-induced blindness) is in the eye of the beholder.

 

<---- before viewing that website

8) <---- after viewing that website (add the dog & cane in your mind's eye) LOL!

 

A few points from his comments:

 

"Brickwalling as it should be" -- this infers that there's some "intelligence" behind the processing that allows it to clip a la AdLimiter or similar, where peaks are smoothed, not simply cut off with a machete.

 

"you instantly can achieve a "mastered" feel to the track and i have tended to end up with a lot more dynamic range in my mixdowns as a consequence" -- how does limiting result in an increase in dynamic range?

 

One of the things you left out of your quotes was:

"just tried upping output 1-2 instead of master volume and it works fine as well, it used to cause problems with monitoring the levels in 6 iirc."

 

So is it the master fader that creates this instant mastered sound? NO! Because the master fader -- as I said before -- only remotely controls the level of your outputs. This is what that guy said as well.

 

So is the magical mastered sound created at the output? Hmmm... Well, unlike the individual channels which operate at 32 bit float, the outputs are 24 bit. If you put the signal into the red at the outputs you get clipping. If that clipping sounds pleasing to some people, well, what can I say other than "beauty is in the ear of the beholder".

 

Tell you what... why not post a short segment of one of your mixes that peaks at 0 and another that clips +6. Don't include any links to which one is which. Let people listening to them guess which one sounds better. Then we can make an evaluation, at least based on whatever kind of music you're making. Maybe others can do the same and collectively we can A/B them and see if this magic mastering trick is for real or not.

[altairuk2008]

how does limiting result in an increase in dynamic range?

 

i think he is saying he gets better dynamic range by "pushing the master fader to +6" rather than using a traditional limiter...obviously an unlimited mix is going to have more dynamics.

 

The thing is he is a well respected dnb producer who has had an absolute ton of releases out since the early 90's including a top 10 hit in the UK singles chart so i just assumed he must known what hes talking about, but some of it didnt quite sit right with me hence why i posted on this forum to get others opinions.

 

in a few minutes ill post up a clip of one of my tracks peaking at 0 and then the same clip with master volume at +6...then you can say what u think

[David Nahmani]

a well respected dnb producer who has had an absolute ton of releases out since the early 90's including a top 10 hit in the UK singles chart so i just assumed he must known what hes talking about

 

That's not necessarily true. Linda Perry is an example of a very successful producer who says clearly she doesn't understand most technical stuff and just use her ears.

 

That guy may be using his ears to do something "right" (in the sense that it sounds better to him - which should be all that matters), but his technical interpretation of what's going on in Logic is wrong.

[altairuk2008]

Ok here you go...

 

I could only push the fader to +4.5db without audible distortion, anythying over that would make certain peaks distort.

 

Im not gonna try and make people guess what clip is what as its pretty obvious the louder clip is the +4.5db one.

 

anyway here is the example

 

http://www.sendspace.com/file/mwwro5

 

 

IMO this guy has it backward. "Red" levels on the track or instrument channel strips do not introduce distortion, red levels on output channel strips do.

 

this is what i was told, because of logics 32 bit floating point engine you can run audio/instrument channel strips into the red and not notice any distortion but that doesn't apply to the output fader.

[David Nahmani]

Is +4.5 dB the peak level of the sample, or the position of the fader (or both)?

[altairuk2008]

Is +4.5 dB the peak level of the sample, or the position of the fader (or both)?

 

+4.5 is the position of the output fader. the highest peak was at +4.1db (id have thought it would have been +4.5 seeing as before i put the fader to +4.5 it was peaking at exactly 0db)

 

for the first example the position of the output fader was 0.0 and the track was also peaking at exactly 0.0

[ski]

First of all, thanks a lot for taking me up on this idea and taking time to post a track for A/B.

 

After adjusting for the difference in level, the very first thing I heard was a kind of unpleasant "click" on the attack of the kick but overall the kick sounded a little bit beefier . Then at around 2:13 the background vocals got a little crunchy in the left speaker . Overall the HH sounded a little harsh too .

 

I heard a couple of wnat sounded like dropouts, but I'll chalk that up to it being an .mp3

 

Dynamics: one thing I noticed was that the swelling bass sound (towards the end of the clip) actually did sound more dynamic, to my surprise. It also sounded a little rounder and fuller.

 

This is all very nitpicky stuff, to be sure. But overall I found the second half a bit "annoying" to listen to, whereas with the first half I could just "float", if you know what I mean.

[David Nahmani]

But overall I found the second half a bit "annoying" to listen to, whereas with the first half I could just "float", if you know what I mean.

 

That's very interesting, because that sounds very close to a listener's typical reaction to an over-compressed mix.

[altairuk2008]

ok cool. could you tell me at what time the drop outs occurred as i couldn't hear any but then your ears are probably more trained than mine.

[ski]

ok cool. could you tell me at what time the drop outs occurred as i couldn't hear any but then your ears are probably more trained than mine.

 

1:56 and 2:02

 

Now that I listen to it really closely (like, actually concentrating on it rather than surfing the web) I think what I'm hearing are some 32nd note HH's under the vocal. They have the effect of making the vocal sound like there's a tape dropout. And it's a tiny bit more pronounced in the louder version.

 

ooh, tape!

[fader8]

the very first thing I heard was a kind of unpleasant "click" on the attack of the kick but overall the kick sounded a little bit beefier . Then at around 2:13 the background vocals got a little crunchy in the left speaker . Overall the HH sounded a little harsh too .

Isn't that the recipe formula for DnB?