How are audio signals routed in a mix? It is gain staging. With this simulator, you can send a musical source through six actual gain stages. With a click of the mouse (or with speedier computer keyboard control), you’ll be able to hear changes in levels, even identify overloads. The idea is to maintain a healthy signal-to-noise ratio but also preserve headroom before the final bus.
Each point in the signal chain is represented by a vertical fader, six of them on the interface. There’s a gain slider, a peak meter and a lamp for the clip indicator at each stage. From left to right they are: input trim, insert input, compressor out, channel fader, bus trim, and master out. Adjusting those faders sets the gain at each handoff. If a signal coming into one of those stages clip (goes to zero dBFS), a red lamp lights up. Once clipped, it can’t be recovered through lowering the volume later on; the flattened waveform is gone.
How to Use the Gain Staging Simulator
To start the audio flowing, click Feed the console. A signal should now be coming into the chain from the source. By default that’s a bass-and-drum loop; press Source to choose either a 1 kHz calibration tone or electric-key chords. Use the calibration tone to make precise tweaks and the loops for audible examples of how clipping affects real-world material.
To set your total listen level, use the Master monitor slider. This doesn’t affect the gain structure inside. Drag the faders while watching the meters and the headroom rail at the bottom of the screen. The headroom rail is an indication of how far away you are from 0 dBFS with respect to whatever target you’ve selected.
As you set levels, the Engineer’s note section give you a real-time commentary on what you’re doing. If you fall below target, go above target, or land right on the mark it will let you know. It will estimate your signal-to-noise and noise floor based on your gain distribution.
To move between and tweak the faders, you just use your computer keyboard. To jump to each stage of the chain, push the corresponding number keys from 1-6. Then by pushing the up/down arrows you’ll be able to finely adjust the gain in tiny increments without having to click and drag around. By pressing the space bar you begin/stop the audio feed. If you like, hitting the R key will automatically find the first red lamp. This means it finds the first overload and leaves a decibel of headroom.
A few pre-configured action presets are available that will let you experiment with the widget. Reset all faders back to unity gain to create a normal signal flow, then click on the Calibrate to minus 18 button. Introduce a problematic gain structure with multiple stages pushed too high, then try to identify and fix the first point of clipping by clicking on Load a hot mistake.
Instead of aiming at the usual minus 18 dBFS, change the target challenge to go after peaks closer than minus 6 dBFS or even minus 12 dBFS. The point of gain staging is to be able to tell where you are clipping. In addition, as the simulator reiterates, when something clips and you fix it further down the chain it doesn’t undo what’s already happened. This is illustrated by pushing the Trim first red lamp button which adjusts the first stage it sees that’s clipping.
How does that sound compared to manually dropping your subsequent fader? It’s the only way to get the wave form back to its proper shape.
The Headroom Rail
This will give you a visual idea of what level you’re getting out. As you increase the master gain, the headroom rail will fill as your peak reaches closer and closer to your target level. Look at the Engineer’s note for a quick indication that your signal is healthy. You want a high signal-to-noise ratio that shows you your gains is set just right. They aren’t too hot, they aren’t too low. Try to maintain your final bus at plus or minus a single decibel from your chosen target.
The widget has a fullscreen option for the meters and patchbay, which can be helpful if you’re using it on a smaller display or just want to concentrate on gain staging without distractions. If you ever get confused about the keyboard shortcut and control options, there’s a help panel that quickly shows what they do. By default, it stays out of sight so as not to clutter up the UI, but you can summon it with the How to play button.
Play around with your different settings in terms of both source material and gain. See what happens when you push one stage into the red. And then back off using the trims. You’ll find that changing the input trim alters the signal level everywhere along the chain. It’s all about feel, and this type of hands-on experience builds an intuitive understanding of levels. It emulates the way a signal flows through an actual system with clipping points along the way that can’t be undone. It’s just like how digital plugins or analog gear will hard clip at 0dBFS. Using this widget will help you build up those skills that you’ll use in your real world mix session. And you’ll discover that even distribution of gain throughout the chain increase dynamic range.
Experiment with each of the various presets and controls. Dial in exact levels by using the calibration tone first. Next, try out some music playing through the loops. Make quick and efficient adjustments using keyboard shortcuts. You want your signal to be high enough for a good signal-to-noise ratio yet not so high as to clip it.
Gain staging is always important for every mix. You want compressors, limiters, etc., to do their job correctly. You also avoid having to boost things so hard later on that they create more unwanted noise. The simulator will let you safely experiment and learn. And if you mess up, you could of wiped it all back to the beginning.
Watch that estimated noise floor readout in the dashboard. You might be able to increase the signal by increasing gain early in the chain, but doing so will also increase the noise floor. This balance is one aspect of the art of mixing. With the widget, you can see this tradeoff as it happens in real time.
Next, choose your target level using the Target challenge selector. For most digital audio workstations,; 18 dBFS is the typical goal, but other targets may be useful for particular projects. The hotter the target, the less space there is for peak levels and therefore the more care that needs to be taken with the mix. The cooler the target, the more margin for error, though it can mean mixing at a lower signal-to-noise ratio.
In terms of the widget itself, each of the faders represents typical gain stages found on a mixing console. These are limited by their ranges as they would be in reality. For example, there is no point in trying to raise a fader above its max level. It won’t go up. That means you have to work around limitations. This brings more of a real feel to the simulation and forces you to think through your decisions.
Keep your eyes on the clip indicators after every stage. That’s where your overload warnings will be. When you see one lighted, that means that stage is clipping the audio. The solution is to turn down the gain at that stage (or some previous stage). Turning down gain further downstream will simply make the clipped signal quieter, but not clean it up.
It’s been set up with an eye on efficiency. Keyboard shortcut keys is mapped directly to the six stages of the chain, which means you can move from section to section easily. Fine-tuning of gain controls is handled by the arrow keys. The space bar controls transport and the R key controls repair. Learn these shortcuts and your workflow will be smoother.
You can switch back and forth from windowed to full screen. Switching to full screen gives you maximum space for your dashboard and patchbay, while keeping the rest of the page out of sight in windowed mode. Use whatever helps you concentrate most effectively.
Keyboard Shortcuts and Help Panel
A summary of keyboard shortcuts and controls can be found in the help panel. If you want to remember how the simulation works, or need to know what a particular keybinding is, this panel is helpful. Because we didn’t want to clutter up the interface with too much going on, the panel is also collapsible. Use it as a quick reference whenever you need it.
Gains are one of those things that get better with practice. Experiment with pushing them around until you feel you have a good handle on how it changes the signal. Next, set a target level in mind, then bring the gain down trying not to clip. Do this a few times and your fingers will start to remember what works and you’ll develop an ear for how much gain is needed.
It doesn’t judge your decisions; it gives you feedback. If something is wrong, the Engineer’s note alerts you. If you’re on track, the widget lets you know that too. Tweak your strategy based on feedback. Over time, you’ll get better at predicting what a tweak will do without actually making it.
Gain staging is an important skill for every audio engineer. This is a targeted training exercise for staging. There are no distractions from a complete digital audio workstation, just levels. Mastering this tool will make you ready to tackle more advanced mix challenges. Set to defaults, then raise the difficulty step by step. Alter the target challenge level; notice what happens to your approach. Try different source material to see how varying the input affects the output.
The bass-and-drum loop has transient peaks that can easily cause clipping. The keys are a more manageable sustained sound. And don’t forget about headroom, leave some room between zero dBFS and your peaks for processing and dynamics. You can see where your headroom is on the headroom rail. Keep it filled but not overflowing. This is what makes your mix sound like a pro.
The simulator uses -72dBFS as a noise floor. This is quite realistic and applies to most preamps and audio interfaces these days. The higher you push the signal, the more the noise floor will increase with it. This also affects your signal-to-noise ratio. Maintain an adequate level of gain where there’s no clipping, but not so much that the signal isn’t clean.
Learn where the clips are coming from by using the Trim first red lamp button. Clicking that will find the earliest point of distortion and trim it. Notice what happens to the levels in the next stages? Try to do this manually by adjusting the faders yourself. This reinforces signal flow.
The responsiveness of the widget makes it clear what’s going on as soon as you begin touching the faders. The audio and the meters respond instantly to changes you make. That instant feedback teaches you what will happen with any adjustment you make. What does a clean signal sound like? A clipped signal?
When your ears are tired, take a break. Listening closely for slight changes in levels is key to gain staging. If you aren’t making good decisions because your ears are tired, take a minute off and come back refreshed. You’ll make better adjustments.
Now share what you’ve discovered with other aspiring audio engineers. Describe the impact of varying gain structure on the mix. Explain why it’s critical to fix things at the beginning of the chain. There is nothing better than teaching others to cement your knowledge. It also helps you demonstrate things.
So continue to experiment. In a virtual world, it doesn’t matter if you mess up. You’ll be able to reset and start over. That’s how we learn and that’s how we explore with total freedom. Have fun learning gain staging. Clean and dynamic is what you want to hear as a result. Never clip anything, ever, to keep things sounding good. Make sure the output is at or near the target so it will be compatible with other systems. Develop those habits by using the simulator. You’ll thank yourself later when you’re in real mixing sessions.
With that, here’s everything you need to know about working with the Gain Staging Simulator. Begin entering signals into the console, bring up the faders and start tweaking around. Use the keyboard shortcuts to increase efficiency. Get lost? Check out the help panel. Regular practice will make perfect. Proper gain staging is a benefit for your mixes. Enjoy the journey down the signal chain.