A gain staging tone?

Steinberg Lounge
21

Hi, sorry it took so long to respond. I’d have to post some screen shots to show examples.

Kevin, Mosaic, the topic I’d suggest you both explore more is “Unity Gain.” This means, very basically, that input signal is equal to the output signal. While a 32 bit file might not be able to be “clipped” this is really another question. We’re talking, here, about the system’s audio inputs and outputs and those can be clipped. Be careful is you start changing Cubase’s defaults on this!

I’d suggest working with the TG (Tone Generator) and you’ll quickly see what’s going on with it. I"ll post a few screen shots next week some time. Maybe we’ll get lucky and some other people will as well. Setting your base-line levels really is a very important thing to discuss. I’m sure some of the others here could offer suggestions for optimizing signal quality and preserving headroom and how the TG can help that process.

Most professional mixing desks include a built-in TG which is used to establish “line-up” levels. Typically, Test Tones are recorded at the head of nearly all mixes and masters, TV spots and shows, films. This way one facility knows what levels were used in a recording it receives for use in whatever purposes. Test tones, combined with a simple verbal slate is essential for a clean hand-off. “This was recorded on (date), at (location), by so and so, using a sampling rate of X, time-code (give TC reference used), on (recorder type), other relevant information (camera roll, e.g.) as needed, contact information (or not – depending on the client :imp:) … What follows is line-up at 1K referenced to X (Reference level you used)” 60 seconds of Tone at the stated reference level, sine wave understood. (For video, the camera displays color bars, the audio channels have the tone, “bars and tone.”)_

Studio Mixes and Masters typically have a full set of tones at different frequencies and levels to help the engineers line up their levels with a previous studio’s levels.

In the Tape Days, professional studios had very expensive Test Tapes that were pre-recorded with a whole host of Test Tones for different purposes – setting levels, biasing tape deck inputs and so on, checking a submitted tape’s stated levels against a known reference, checking the performance of a recorder.

In Cubase, each audio channel has the Pre-Gain setting. So to get an optimal signal chain, you might consider reducing the channel trim by say -3 to even -10 db or more; the TG can be a great help with this kind of thing. Preserving headroom, optimizing dynamic range. This way your mastering engineer has room for the finishing touches or whatever else is needed for the project.

Anyway, I’ll post a few screen shots and maybe we’ll get lucky and some others will jump in on this. I hope this helps a bit. It’s something worth working with and it will help your tracks sound better and if you have to hand-off to another studio, it will help them get it right. Good luck on this. It is important. Some great youtube videos over at MixBus TV on subject – that’s one place I’d look for sure.

Good luck. :slight_smile:

22

Very nice post, thank you.

I wanted to highlight something about the part in bold - it’s important to note that if the level display is set to “input”, you will not see changes in the fader’s displayed signal level when the pre-gain trim control is manipulated.

So if the signal is hot enough coming in to a channel to be way high in the fader level, adjusting the pre-gain trim will not change that.

23

So I’m going to try to map this to my current way of recording.

Currently, I try to mix so that my master buss maxes out at -4 dB so that I have headroom for when I do mastering (separate project). However, I have at times accomplished this by pulling back on the master fader. It sounds like, instead, I should avoid doing this at all costs since it would mean that the individual tracks are still too hot.

In other words, mix the project so that the master fader is set to unity and the max peaks are still at -4 dB. Does this sound about right?

Now let me add another bit to this: in the (near?) future I may send out the signal through a tube pre to warm things up (in lieu of a reel-to-reel tape deck) as a prep step for mastering, but right now I mix / master 100% in the box. Does this all still apply?

24

from what I’ve been learning it seems De rigueur to have the faders on input and set to between neg 12 and neg 18 with the master set to around neg 10…this leaves lots of headroom for whatever you wanna chuck on it later…seems reasonable to me…doing it now and I feel like I’m nearly a producer… :laughing: :laughing: :laughing:
I was always recording things too hot because i never had the faders set to input, now I’m operating this new (to me) system everything sounds so much cleaner…
I have the track faders set at neg 6 so there is some up and down room :slight_smile:

25

Not necessarily. Cubase can handle it, you can’t clip there. The only time an individual track is “too hot” is if you’re rendering it directly to hardware (where it might cause the hardware to operate in too high a range, and sound strained, or ultimately distorted), … OR … even if you’re staying in the software domain, if the track is routed to something like a plug-in that is meant to be fed audio at a lower level.

Other than that, if you are comfortable seeing your levels pegged way up at the top, you don’t have to do anything.

26

+1 good point. My omission, glad you spotted it.

Getting the gain structure right is so important regardless to whether the project is a starting vocal, guitar demo or a more advanced project.

27

.

+10k.

Maybe someone here can help with a gainstaging question: When I have several tracks routed to a single group (for example, a voice with 4 sends to four comps, each in turn routed to one group; then that group and the dry voice routed to another another group), the input to that group is hot/hot/hot, even if all the individual tracks are not.

Now I know how to process it accordingly so it doesn’t hit the inserts on that group or the next group so hot (for example, using the input trim).

But it does bother me to see the input signal so hot on that fader. I don’t guess there’s any way to avoid that in the kind of set up I describe? Or maybe there is? …

28

I think there’s possibly some confusion going on. I think Alexis made good points though, for example.

In my opinion:

It isn’t.

I think there’s some confusion between “Calibration” and “Gain Staging”. When you calibrate your room/system you may indeed end up changing gain at different stages, which sounds like “gain staging”. And when you do this calibration a tool is indeed a source like a signal/test generator or pre-rendered audio file with some reference content.

But “gain staging” in a practical real-world mixing setting doesn’t require a test signal at all. In fact, I don’t even see the point in using one in an already calibrated system.

Gain staging is about setting the correct gain at different stages of the signal flow. If your input is hot, then you need to drop the level BEFORE that input. So if you’re looking at an input channel in Cubase and its meter is set to show channel input and is reading too hot, then you can’t change that in Cubase, because the meter ‘taps’ the signal at the very input. So, you have to find a different stage at which to change gain. For example:

Mic - Mic Preamp - A/D converter - DAW channel input

If the level at the DAW channel input is too hot, most likely you want to lower the output of the Mic Preamp. You probably don’t want to lower the A/D converter because a) it might not have controls that allow it, or b) because the only way you can is using its software mixer which likely handles levels after conversion, so if you’re clipping in your DAW you’re likely clipping there as well.

Another example:

Mic - Mic Preamp - compressor - A/D converter - DAW channel input

Here you can lower the output of the compressor instead, assuming it is receiving a correct level from the Mic Pre. As long as the level is lowered before A/D conversion you’re fine at that stage.

To me it doesn’t make sense to get into changing gain anywhere in the signal chain unless there is a reason for it. And that reason has to be the signal that’s flowing through the chain. Since it depends on the signal, it doesn’t really make sense to use a test generator. For example:

You insert a test generator on an input channel. You set the plugin to output a sinewave at 0dBFS (full scale). You then pull down the fader 10dB so that the output of that channel now reads -10dBFS. Now what happens if the actual signal you want to record - not the test generator - is averaging -20dBFS? The output of that channel is now -30dBFS. So you end up undoing your pre-set fader so that the output is where you want it. In other words there appears to have been no gain (bazing! pun-double-extra-points) in doing so.

To me, no. I think the bigger issue is in which domain you are when you are changing gain. If your entire signal chain is floating point up to the converters, then I don’t see how it makes any difference exactly where you lower your levels - with the exception of individual plugins possibly not operating optimally.

I hear mastering engineers asking for some headroom, but to me it seems to be more an issue of convenience rather than technology. After all, what difference does it make if you drop gain in your DAW or if they do it? Again this assumes staying in the same domain, which you in your example are doing since you’re mastering stuff yourself.

Well, sort of not. As you leave the digital domain for the analog, you have two things to worry about: 1) A/D/A conversion, and 2) optimal operating levels for your analog processor (tube). So, your converter likely has an optimal operating range and you’d probably want to be close to it, and the same applies to your tube processor. You’d have to figure out where to change gain to get the proper level for your tube in case you want it to overdrive more or less. So, if it has an input adjustment that could do the trick, and if not maybe run the levels out of your converters, either on them directly (probably not) or in your DAW (probably).

I don’t think that’s wise.

First of all, the meters should reflect what is important to you as an engineer. If you’re recording, you want input most likely, since that’s what’s of the greater concern. Of course, if you have a converter that has level indicators that may be enough. If the converter shows you if you clip the converters, then you don’t really need the meters to be set to input. (I’m assuming by “faders on input” you meant “meters on input”) Then, when you’re mixing, you’ll probably be better off with them showing output instead (though not in all cases). So you can switch between the modes as you see fit.

Secondly, as I mentioned earlier, there’s no inherent benefit to just drop faders by 12-18dB. You use them to adjust level if needed.

29

So, here’s the in my opinion biggest benefit of “gain staging” within a DAW. You can pull down faders to get the input you feel is most appropriate, and it makes sense to do so because sooner or later the level HAS TO drop before hitting the converters. Either you do it before hitting that final group, or you do it by lowering that group channel, or you do it by lowering the master. So in a sense I think it’s a matter of how you want to work and what you feel comfortable with.

I work mostly in post-production and levels are pretty well defined through standards. I also have a personal workflow that often ends up with similar processing in a lot of different projects. Since it does, I typically have templates with plugins already instantiated but turned off. So in my workflow I typically continuously adjust gain to have it sound loud enough but not too loud, and as I activate plugin after plugin in the chain I have to do little tweaking. If I allowed the signal to go hot at one stage then the plugin in the following stage would have to be adjusted a lot more every single time. So to me it’s about saving time by having things act predictably.

Know what I mean?

30

This has been an enlightening thread. Thanks everyone, especially Lydiot, for the insight.

I’ll create a separate thread asking for input on equipment recommendations.

31

Hi, good posts here.

Kevin’s original topic, gain staging tone was really a two or more questions in one post and I found myself going into some of the Uses of Tone Generators in the studio. I’m glad other posts covered the gain staging questions and Tone Generators can help with that.

Gain Staging, as some of the posts point out, is really a different question. There’s certainly a lot of excellent youtube videos on some methods for it from very good, working engineers. Just by listening to the work in “Made with Steinberg,” it’s obvious people in t–his forum are getting some excellent results regardless of their methods.

Gain Staging of tracks in a mix, is, of course, another big topic unto itself and posts in this thread have covered some interesting and useful way to approach that.

Here’s one method I use. After my tracks are recorded and I’m ready to begin getting some mix ideas going, I, first set all my tracks to Unity Gain along with any Sub-Groups and the final stereo Master Output. Turn down the monitors and let the tracks play with “hold peaks forever” on. After the section or song is finished, I observe the peaks on each track.
For example, you’ll see something like –
Track 1 +2, Track 2, +6, Track 3, +3, Track 4, +9 and so on.

Do the same for your groups and effects channels after checking your peaks on those and on the Stereo Master Output. Make note of the Meter scale you use since it is the reference generating your values, so know what scale you’re working with, and, if you get tracks from someone else, it’s best to know what scale they used in recording those tracks. Cubase offers several different ways to scale your meters.

Now, reduce the channel input trims by the same amount as the peak. This way your peaks are at “zero” so to speak and zero might be -20. You might have peaks at -3, or less some might suggest is best. This way the tracks to be mixed are aligned, in terms of gain, to the gain structure of the system they are being mixed on.

Anyway after the channel input trims are set, mixing can begin and you know where you are in terms the gain structure of your tracks. There’s much more to this topic and the actual math on it will make your head hurt, it does mine. I invite others offer their views on best practices for gain structuring tracks and mixes in Cubase, and, again, thanks to those who already covered this topic. Very helpful posts.

So, at last, after the track gains are set for the mix, it’s time to turn up the monitors, get busy mixing and enjoy your cool music.

32

I personally don’t touch speaker levels unless I’m either tired or need to check on low volume. Instead I have it calibrated so that content I deliver for post plays back at a nice level. Loud stuff sounds loud, soft stuff soft, and the stuff in the middle “medium”.

If anything I then do the opposite and pull the track faders down and add things back one by one. If I’m mixing music I’ll pull everything down and bring up drum kit mics. Balance. Bring up bass until it works with the kick. Bring up other rhythm instruments like guitars, keys etc. All of that stuff one by one. By doing it that way it never ends up being way too loud. When it sounds loud it is loud.

In addition I’ve gone through my metering setup and set the colors and response time so it makes sense to my eyes. They go from green at the bottom to yellow, then red. As long as a signal is mostly yellow it’s around -24dBFS. Peaks go into red (fine), and it sometimes drops to green (fine).

But as you said, to each his own.