To get the best sound when mixing music, you need to understand how your tools work.
That means knowing about concepts like dynamic range, headroom and signal-to-noise ratio.
They may seem like dry technical topics, you can easily make mistakes that make your sound worse if you neglect them.
In this article I’ll break down signal-to-noise ratio to explain what it is, why it’s important and how it affects your workflow.
Let’s get started.
What is signal-to-noise ratio?
Signal-to-noise ratio is a measurement that describes the performance of an audio system in terms of noise, signal quality and fidelity. It’s calculated by comparing the strength of the audio signal to the base level of noise in the system.
A high signal-to-noise ratio means that the content of your sound is strong and clear in comparison to the noise of your audio gear.
A low signal to noise ratio means that the system noise is very loud compared to your sound. This could make the content of the sound obscured, degraded or hard to hear.
You’ll often see strong signal-to-noise ratio listed as a positive feature of well-designed gear.
That’s important, but understanding the concept will help you get better results from every link in your—chain from tracking to the final master.
A high signal-to-noise ratio means that the content of your sound is strong and clear in comparison to the noise of your audio gear.
Noise floor
If you understand gain staging you’ll know that the usable area of an audio system is the space between its noise floor and its clipping point.
If that sounds complicated, you might want to go back and brush up on the basics of gain staging to get started.
So what does noise floor mean exactly? Think of it this way. No audio gear is perfect—no matter how much it costs.
Every audio system has a small amount of noise it produces just by being on. That level is the noise floor—it’s the amount of the noise your gear naturally produces—even with nothing plugged in.
Modern gear has very good noise performance, so you’ll often see manufacturers list noise floor figures more than 100 dB below the max.
Even so, there are plenty of ways that the noise floor can creep up and drag your signal-to-noise ratio down.
Every audio system has a small amount of noise it produces just by being on.
Clipping point and headroom
Good signal-to-noise ratio means your audio is strong enough to stay well above the noise floor of your gear.
But what if you go too far in the other direction? That’s when you’ll reach the clipping point.
Today’s music equipment is so good that most producers might not notice the noise floor unless there’s a problem.
But the clipping point is easy to reach if you’re not careful. Running your levels too high in your DAW sessions or recording your inputs too hot can easily produce signals over the 0 dBFS maximum.
Keeping good headroom means staying in the optimal range above the noise floor and below the clipping point.
Dynamic range
If the noise floor and clipping point are two the extremes, dynamic range is the entire usable area between them.
Good headroom is the sweet spot, but every signal in your system goes up and down over time.
That means that even if the signal is in the correct range on average, it might be much higher or lower at specific points.
I’m talking about moments like a fade-out at the end where sounds die out gradually until you can no longer hear them.
Big differences in volume can be so dramatic because the systems we listen to music on today have impressive dynamic range.
It’s another popular figure for gear manufacturers to brag about the quality of their equipment
But dynamic range is another part of the equation when it comes to signal-to-noise ratio.
For example, older analog gear often has a higher noise floor and lower clipping point. This means that the dynamic range is lower overall and the sweet spot of good headroom is narrower.
Why signal-to-noise ratio matters
Every link in your recording chain has an impact on your final product. Each individual piece of gear comes with its own noise and performance issues.
But how you use it matters too. Where do the sounds in your music come from?
If you record sounds with a microphone or use a DI to record hardware gear direct that equipment can introduce noise too.
Even if you’re just using sample packs and VST instruments, you can accidentally increase the total noise in your source if you’re not careful.
You never want to ruin a perfect take or a great mix with excessive noise that could have been avoided.
How to keep good signal-to-noise ratio
With so many elements to keep track of it might seem difficult to manage noise issues across all your entire signal chain.
Luckily, the concepts of headroom and noise floor apply in almost every audio system. If you’re aware of how they work you can easily avoid the worst issues.
The best approach is to always aim for the happy medium between the noise floor and clipping point no matter what piece of gear is involved.
That means listening for self-noise, gain staging properly and leaving enough headroom at every point in the process.
If you follow those rules and use quality gear, there’s no reason you should have excessive noise in your tracks and mixes.
To recap:
- Noise floor is the level of system noise produced by your gear
- Clipping point is the level above which signals become distorted
- Dynamic range is usable area between noise and clipping
- Healthy headroom means leaving plenty of space between for your signal to breathe on both ends
- Signal-to-noise ratio is the level of the system noise compared to the strength of the audio signal
Golden ratio
Signal-to-noise ratio sounds like an abstract scientific term, but it has real consequences for the sound of your mixies.
It’s part of an interactive set of audio qualities that every producer should understand.
But if you’ve made it through this article you’ll have a great start on issues related to noise floor, clipping point, dynamic range and headroom.